Amyloid Deposition Within a Large Pelvic Chronic Expanding Hematoma

Introduction/Objective

Chronic expanding hematoma (CEH) is a relatively rare complication of trauma that is usually mistaken for a soft tissue neoplasm. The identification of amyloid protein is of paramount clinical importance to exclude serious conditions causing systemic amyloidosis.

Methods

The case was retrieved from the pathology files at the University of Miami Hospital (UMH). Morphology and special stains were reviewed. The study was approved by the Institutional Review Board at UMH.

Results

A 44-year-old man with past history of a stab wound in the left buttock in the 1990s, was admitted with worsening abdominal pain, constipation, urinary obstruction and acute kidney injury. CT-scan showed a large mass involving the left gluteal area and pelvic cavity involving urinary bladder causing outlet obstruction and bilateral hydroureteronephrosis. Multiple radiology-guided biopsies were taken all identifying only fibrin, blood cells, and necrotic inflammatory cells. Excision of the gluteal mass and drainage of the pelvic component was performed confirming the diagnosis of CEH. Amyloid deposition with congo red stain birefringence under polarized light was identified. The patient’s symptoms and renal function improved and have been under follow-up for 1 month.

Conclusion

We have identified amyloid protein deposition whiting a CEH. This is an unusual finding with no previous description found in our search. The identification of amyloid whiting tumor-like lesions is relevant to exclude causes of systemic amyloidosis.

Novel Gene Fusions in Rhabdomyosarcoma

Introduction/Objective

Rhabdomyosarcoma (RMS) encompasses a heterogeneous group of tumors with striated muscle morphology and/or immunophenotype. Molecular analysis of rhabdomyosarcoma has identified a number of aberrations useful for classification. Initially, fusion associated RMS was restricted to tumors with FOXO1 rearrangements, confirming the diagnosis of alveolar RMS, and identifying patients with poor-outcome. Spindle cell RMS, have been described with VGLL2 fusions, EWSR1/FUS-TFCP2 rearrangements, and myoD1 mutations. In addition, NCOA2-MEIS1 fusion gene was recently described in two primary intraosseous RMSs sharing primitive histology. Herein we report two cases of spindle cell RMS, harboring different novel fusion genes, one presenting EP300-VGLL3, and the second with NCOA2-MEIS1 and CAV1-MET.

Methods

Two cases of RMS were retrieved from the pathology files at the University of Miami Hospital (UMH) and Jackson Memorial Hospital (JMH). Morphology and immunohistochemistry were reviewed. A commercial genomic profiling test for both cases was also analyzed. The study was approved by the Institutional Review Board at UMH.

Results

Case #1 is a 36-year-old man presented with a 1.5 cm submucosal mass in the ventral left tongue. The biopsy revealed a malignant spindle cell neoplasm and immunohistochemistry showed tumor cells positive for desmin, SMA, myogenin and MYOD-1. A partial glossectomy was performed, achieving negative resection margins. Next- generation sequencing (NGS) identified an EP300-VGLL3 fusion. The patient is currently being followed and has been disease-free for 6 months. Case #2 is a 19-years-old male with no medical history admitted with lower extremities weakness and a large expansile pelvic bone lesion and multiple spinal metastases. Biopsy from the pelvic lesion revealed malignant primitive round cells and short spindle cells arranged in fascicles which were positive for desmin, MYOD-1, TLE-1 and CD99 and focally positive for myogenin and WT-1. NGS identified two fusion genes, NCOA2- MEIS1 and CAV1-MET.

Conclusion

Different types of rhabdomyosarcoma are associated with a variety of different gene fusions and some may be of prognostic significance. Our two cases are the first reported with EP300-VGLL3 and CAV1-MET fusion genes. CAV1-MET oncogenic potential has been described only in lung cancer. The prognostic significance of rhabdomyosarcoma with novel gene fusions requires longer follow-up and the identification of additional cases.

Albiglutide and cardiovascular outcomes in patients with type 2 diabetes and cardiovascular disease (Harmony Outcomes): a double-blind, randomised placebo-controlled trial

BACKGROUND

Glucagon-like peptide 1 receptor agonists differ in chemical structure, duration of action, and in their effects on clinical outcomes. The cardiovascular effects of once-weekly albiglutide in type 2 diabetes are unknown. We aimed to determine the safety and efficacy of albiglutide in preventing cardiovascular death, myocardial infarction, or stroke.

METHODS

We did a double-blind, randomised, placebo-controlled trial in 610 sites across 28 countries. We randomly assigned patients aged 40 years and older with type 2 diabetes and cardiovascular disease (at a 1:1 ratio) to groups that either received a subcutaneous injection of albiglutide (30-50 mg, based on glycaemic response and tolerability) or of a matched volume of placebo once a week, in addition to their standard care. Investigators used an interactive voice or web response system to obtain treatment assignment, and patients and all study investigators were masked to their treatment allocation. We hypothesised that albiglutide would be non-inferior to placebo for the primary outcome of the first occurrence of cardiovascular death, myocardial infarction, or stroke, which was assessed in the intention-to-treat population. If non-inferiority was confirmed by an upper limit of the 95% CI for a hazard ratio of less than 1·30, closed testing for superiority was prespecified. This study is registered with ClinicalTrials.gov, number NCT02465515.

FINDINGS

Patients were screened between July 1, 2015, and Nov 24, 2016. 10 793 patients were screened and 9463 participants were enrolled and randomly assigned to groups: 4731 patients were assigned to receive albiglutide and 4732 patients to receive placebo. On Nov 8, 2017, it was determined that 611 primary endpoints and a median follow-up of at least 1·5 years had accrued, and participants returned for a final visit and discontinuation from study treatment; the last patient visit was on March 12, 2018. These 9463 patients, the intention-to-treat population, were evaluated for a median duration of 1·6 years and were assessed for the primary outcome. The primary composite outcome occurred in 338 (7%) of 4731 patients at an incidence rate of 4·6 events per 100 person-years in the albiglutide group and in 428 (9%) of 4732 patients at an incidence rate of 5·9 events per 100 person-years in the placebo group (hazard ratio 0·78, 95% CI 0·68-0·90), which indicated that albiglutide was superior to placebo (p<0·0001 for non-inferiority; p=0·0006 for superiority). The incidence of acute pancreatitis (ten patients in the albiglutide group and seven patients in the placebo group), pancreatic cancer (six patients in the albiglutide group and five patients in the placebo group), medullary thyroid carcinoma (zero patients in both groups), and other serious adverse events did not differ between the two groups. There were three (<1%) deaths in the placebo group that were assessed by investigators, who were masked to study drug assignment, to be treatment-related and two (<1%) deaths in the albiglutide group.

INTERPRETATION

In patients with type 2 diabetes and cardiovascular disease, albiglutide was superior to placebo with respect to major adverse cardiovascular events. Evidence-based glucagon-like peptide 1 receptor agonists should therefore be considered as part of a comprehensive strategy to reduce the risk of cardiovascular events in patients with type 2 diabetes.

FUNDING

GlaxoSmithKline.

p53 overexpression in Ewing's sarcoma/primitive neuroectodermal tumour is an uncommon event

Aim-To determine the presence of p53 overexpression in Ewing's sarcoma/primitive neuroectodermal tumours (ETs) and to assess whether p53 accumulation has any prognostic value.Methods-From a prospectively compiled database of 76 patients with ETs, suitable tumour tissue was available for 38. The monoclonal antibody pAb1801 was used to detect p53 nuclear protein overexpression. Results-Nuclear staining was detected in the tumours of three (8%) of the 38 patients. Where tumours stained positively, over 10% of the tumour nuclei were postively stained. All three patients whose tumours overexpressed p53 died and in a relatively short time compared with the patients who did not overexpress p53 (mean 3.7 months compared with a mean of 38.7 months in the p53 negative group).Conclusion-Overexpression of p53 in ETs is an uncommon event. Overexpression of p53 has repeatedly been shown to correlate closely with p53 point missense mutations and therefore this oncogenic event appears not to be of primary pathogenic importance in ETs. There is a tentative indication that those uncommon ETs in which p53 overexpression can be detected may be-have more aggressively.

Predictive value of histologic tumor necrosis after radiation

Postsurgical evaluation of histologic changes of tumors after preoperative chemotherapy and/or radiotherapy has been a routine clinical practice of pathologists and oncologists. There appears to be secure evidence that the extent of tumor necrosis vs. viable tumor cells postchemotherapy is a clinically useful predictor of outcome. The significance of histologic tumor necrosis after radiotherapy, however, has not been clearly established and deserves further investigation. We investigated the correlation between histological extent of tumor necrosis, survival of tumor transplants, and radiation doses in an experimental model using three human tumor xenografts. Three human tumor cell lines were investigated: STS-26, SCC-21, and HGL-21. Tumors were grown subcutaneously in athymic nude mice and received external beam radiation of different doses. Tumors were excised 2 weeks postirradiation. One-half of the tumor was divided into 1-mm(3) fragments and transplanted to naive mice. The other half was examined for histologic tumor necrosis. Transplant survival was strongly correlated with radiation dose, TCD(p) (radiation dose that results in local tumor control in proportion, p, to irradiated tumors). In contrast, there was no clear association between transplant survival rate and the extent of tumor necrosis. The experimental model demonstrated a strong inverse correlation between radiation doses and tumor transplant survival. Histologic tumor necrosis did not correlate well with radiation doses or transplant survival rates. Despite common practices in histologic examination of tumors posttherapy, clinical interpretations and implications of histologic tumor necrosis after radiotherapy should be considered with caution.

Chondromyxoid fibroma of the metacarpal

This report describes a chondromyxoid fibroma which developed in the distal part of the second metacarpal of a 12-year-old girl. The tumor is rare, perhaps the rarest of all bone tumors, and the occurrence in a metacarpal of a young female is extraordinarily uncommon.

Orthopaedic implant-related sarcoma: a study of twelve cases

Sarcoma developing in association with a metallic orthopaedic prosthesis or hardware is an uncommon, but well recognized complication. We review 12 cases of sarcomas arising in bone or soft tissue at the site of orthopaedic hardware or a prosthetic joint. Nine patients were male, and three were female. Their ages ranged from 18 to 85 (mean 55) years at the time of diagnosis of the malignancy. Five patients had undergone hip arthroplasty for degenerative joint disease, four had been treated with intramedullary nail placement for fracture, two had staples placed for fixation of osteotomy, and one had hardware placed for fracture fixation followed years later by a hip arthroplasty. The time interval between the placement of hardware and diagnosis of sarcoma was known in 11 cases and ranged from 2.5 to 33 (mean 11) years. The patients presented with pain, swelling, or loosening of hardware and were found to have a destructive bone or soft tissue mass on radiography. Two sarcomas were located primarily in the soft tissue and 10 in bone. Seven patients developed osteosarcoma, four malignant fibrous histiocytoma, and one a malignant peripheral nerve sheath tumor. All sarcomas were high grade. Three patients had metastatic disease at the time of diagnosis. Follow-up was available on eight patients: five patients died of disease 2 months to 8 years (mean 26 months) after diagnosis; two patients died without evidence of disease 7 and 30 months after diagnosis; and one patient is alive and free of disease 8 years after diagnosis. Sarcomas that occur adjacent to orthopaedic prostheses or hardware are of varied types, but are usually osteosarcoma or malignant fibrous histiocytoma. They behave aggressively and frequently metastasize. Clinically, they should be distinguished from non-neoplastic reactions associated with implants, such as infection and a reaction to prosthetic wear debris.

Chondroblastoma-like chondroma of soft tissue: an underrecognized variant and its differential diagnosis

Soft-tissue chondromas are usually composed entirely of mature hyaline cartilage. Infrequently, however, they may exhibit morphologic features that result in diagnostic difficulty. The authors report a series of eight hypercellular soft-tissue chondromas composed of enlarged chondrocytes within a variable amount of chondroid matrix that often demonstrated delicate calcifications and contained numerous osteoclast-like multinucleated giant cells. This histologic appearance closely resembles that of chondroblastoma of bone. However, its extraosseous location, dense cellularity, and poorly formed cartilage can cause confusion with more aggressive chondroid neoplasms of soft tissue. The clinicopathologic features of these chondroblastoma-like chondromas are discussed, emphasizing the characteristics that facilitate their accurate identification.

Reticular perineurioma: a distinctive variant of soft tissue perineurioma

Soft tissue perineurioma is a relatively recently characterized, uncommon tumor composed of perineurial cells exhibiting immunoreactivity for epithelial membrane antigen (EMA). These lesions occur preferentially in adults and may arise in a wide variety of anatomic sites. We report the clinicopathologic, immunohistochemical, and ultrastructural features of six cases of a poorly recognized morphologic variant of soft tissue perineurioma, characterized by a highly distinctive reticular growth pattern. Four of the patients were women, two were men (age range, 34-61 yrs; median, 43 yrs). Four of the cases arose in the subcutis of the upper extremity; three were located distally (thumb, finger, palm), whereas one was situated more proximally near the elbow region. One case each was located in the gingiva and subcutaneous tissue of the inguinal region, respectively. In those cases in which clinical information was available (n = 5), the lesions were asymptomatic and had been present from 4 months to 10 years before resection. Tumor size ranged from 1.5 cm to 10 cm (median size, 4.25 cm). Microscopically the lesions demonstrated a predominantly lace-like or reticular growth pattern composed of anastomosing cords of fusiform cells with bipolar cytoplasmic processes and palely eosinophilic cytoplasm. Nuclei were centrally placed, ovoid to fusiform in shape, and no mitoses were seen. Transition to more cellular areas was focally present in all cases. The stroma was variably collagenous to myxoid. Immunohistochemically all six cases stained positively for EMA but not for S-100 protein. Two cases demonstrated focal positive cytoplasmic staining for cytokeratin, whereas one case was focally desmin positive. Ultrastructural examination of two tumors showed typical features of perineurial cells. Follow up (available in only two cases) showed no evidence of recurrence. Reticular perineurioma of soft tissue represents an unusual morphologic variant within the perineurioma group, which should be distinguished from myoepithelial tumors, extraskeletal myxoid chondrosarcoma, and myxoid synovial sarcoma.

Treatment of epithelioid hemangioendothelioma of bone using a novel combined approach

Radiofrequency (RF) treatment has been used for a variety of malignant and benign conditions. However, treatment of a bone malignancy has yet to be reported. The authors present a 21-year old woman with multifocal epithelioid hemangioendothelioma (EH) treated by a combination of surgical excision, chemotherapy and four RF ablations. Follow-up radiographs of the RF-treated sites reveal no evidence of recurrent disease 71, 58, 49 and 33 months, respectively, after treatment.

Epithelioid vascular tumors of bone: a review and proposal of a classification scheme

Skeletal vascular tumors composed of epithelioid endothelial cells commonly result in diagnostic difficulty. Although tumors with this morphology have been recognized for many years, there is a considerable degree of confusion regarding their nomenclature and classification. In this article what is believed to represent the morphologic features of this family of tumors is outlined, the historical context of epithelioid endothelial tumors is briefly discussed, and pertinent literature and texts pertaining to the subject is reviewed. It is proposed that the osseous epithelioid endothelial tumors should be classified in a similar manner to their soft tissue counterparts and it is suggested that this approach should help to clarify the confusion surrounding this subject of surgical pathology.

Chordoma periphericum: a case report

The authors describe a tumor that had the histologic and ultrastructural features and immunohistochemical profile of an axial chordoma, but arose in the distal ulna. A skeletal survey failed to show any other site of involvement. The tumor was resected, and the patient remains free of disease 2 1/2 years later. Rare tumors with the histologic features of chordoma have been reported in appendicular locations. Chordoma periphericum, a tumor that has the potential to metastasize, needs to be distinguished from parachordoma because no classic parachordoma has been reported to disseminate.

Primary lymphoma of peripheral nerve: report of four cases

Lymphoma presenting as a solitary tumor of peripheral nerve is exceedingly rare, with only six previously reported cases. The authors describe an additional four cases of primary lymphoma of peripheral nerve involving the sciatic nerve (two cases), the radial nerve, and the sympathetic chain and spinal nerve. The patients were two men and two women with an average age of 55.5 years. All tumors were high-grade B-cell lymphomas. Two patients experienced relapse of disease with involvement of other nervous system sites and died of lymphoma. One patient is alive with stable local disease at 57 months. The fourth patient is alive with no evidence of disease at 54 months. Expression of neural cell adhesion molecule (CD56) has been reported to correlate with an increased incidence of central nervous system involvement in peripheral T-cell lymphoma; all their cases were CD56 negative. Recent reports indicate a high proportion of primary brain lymphomas show loss of CDKN2A/p16 gene expression. Therefore, CDKN2A/p16 was evaluated in their patients both by polymerase chain reaction and by immunohistochemistry for the p16 protein. The authors found homozygous deletion of the CDKN2A/p16 gene in one of three patients studied, confirmed immunohistochemically by absent staining for p16. The fourth patient showed absent staining for p16, suggesting inactivation of the gene in this case as well. The two patients with p16 loss both died of lymphoma, whereas the two patients with normal p16 expression are alive. Primary lymphoma of peripheral nerve is a rare neoplasm, usually of large B-cell type, has a variable prognosis, and appears to have less consistent loss of p16 expression than primary central nervous system lymphoma.

Gastrointestinal stromal tumor versus intra-abdominal fibromatosis of the bowel wall: a clinically important differential diagnosis

Intra-abdominal fibromatosis (IAF) is an uncommon benign neoplasm that usually occurs in the mesentery or retroperitoneum and may, on occasion, mimic a gastrointestinal stromal tumor (GIST). Differentiating between these two entities is important clinically because IAF is a benign tumor whereas GISTs frequently have malignant potential. In this study, the authors identified 13 cases of IAF with prominent involvement of the bowel wall as well as 35 GISTs of the small intestine, colon, or mesentery and analyzed their clinical, gross, histologic, immunophenotypic, and ultrastructural characteristics to identify important distinguishing features. Patients with IAF were younger (mean, 34 yrs) than patients with GIST (mean, 54 yrs). Both types of tumors tended to be large, but GISTs were soft and lobulated with hemorrhage, necrosis, or cystification whereas IAFs were firm, tan, and homogeneous. Histologic features characteristic of GIST included the presence of spindle or epithelioid cells with variable architecture, mitotic activity (range, <1-95 mitoses/50 high-power fields [hpf]; mean, 15 mitoses/50 hpf), nuclear atypia, and myxoid or hyalinized stroma. Necrosis and hemorrhage were seen in 16 and 25 tumors, respectively. In contrast, IAFs were composed of broad, sweeping fascicles of monotonous spindle cells with mitotic activity (range, <3-11 mitoses/50 hpf; mean, 4 mitoses/50 hpf), bland nuclear features, and finely collagenous stroma. Necrosis, hemorrhage, and myxoid degeneration were not seen. Immunohistochemical studies performed on a limited number of GISTs and IAFs demonstrated that cells expressed vimentin (100% GIST and IAF), CD117 (88% GIST and 75% IAF), CD34 (42% GIST and 0% IAF), smooth muscle actin (63% GIST and 75% IAF), muscle actin (75% GIST and 75% IAF), desmin (8% GIST and 50% IAF), and S-100 protein (16% GIST and 0% IAF). Ultrastructural analysis of 21 GISTs revealed incomplete smooth muscle differentiation in some tumors whereas IAFs were shown to have complete myofibroblastic/fibroblastic differentiation. Information regarding clinical outcome was available on 29 patients and revealed that three patients with histologically benign GISTs were alive with no evidence of disease at 5 months to 6 years (mean, 3.5 yrs) and one patient with a histologically benign tumor died of disease after 7 years. Of patients with histologically malignant GIST, one died of surgical complications, 10 were alive without disease at I to 13 years (mean, 5.4 yrs), four were alive with disease at 4 months to 15 years (mean, 3.8 yrs), three had disseminated disease at operation, and seven were dead of disease at 10 months to 3 years (mean, 2.2 yrs). Follow up of eight patients with IAF demonstrated that five were alive without disease at 4 months to 15 years (mean, 5.3 yrs) and three had recurrences at 1 (two patients) and 2 years (one patient). In summary, IAFs can have many features (large size, infiltration of adjacent structures, mitotic activity) that can cause diagnostic confusion with GISTs and, importantly, the degree of mitotic activity present in IAFs may overlap that seen in malignant GISTs. These entities can be distinguished primarily by their light microscopic and ultrastructural features but there is a notable overlap in their immunohistochemical profiles. The distinction between these neoplasms is important because there are important clinical implications for the patient.

Giant cell tumors of soft tissue: a clinicopathologic study of 18 benign and malignant tumors

Primary giant cell tumors (GCTs) of soft tissue resembling osseous GCTs are uncommon but distinct entities. Malignant GCTs of soft tissue have been designated giant cell malignant fibrous histiocytomas; however, there is scant data regarding benign GCTs of soft tissue. Eleven benign and seven malignant GCTs of soft tissue were identified from the authors' consultation files and the surgical pathology files of the Vancouver General Hospital and Massachusetts General Hospital. The tumors occurred in adults (eight men, 10 women; age range, 25-89 years; mean age, 54 years) in the extremities (n = 14) and in the trunk, abdomen, and pelvis (n = 4). In each patient the skeleton was normal and there was no history of prior osseous GCT. Tumors ranged in size from 0.8 to 9.0 cm. Eleven occurred in the superficial soft tissue and seven occurred in deep soft tissue. Grossly they were circumscribed and frequently hemorrhagic. Cystic change was present in seven tumors. Nine tumors were partially surrounded by a shell of reactive bone. In all tumors, multinucleated osteoclast-like giant cells were distributed uniformly and evenly among mononuclear cells. The histologically benign GCTs of soft tissue were identical to typical osseous GCTs. The mononuclear cells in these tumors lacked nuclear atypia or pleomorphism, and the mitotic rate within this population was low (mean, three mitoses per 10 high-power fields [HPF]). In the malignant GCTs of soft tissue, the mononuclear cells exhibited anisocytosis, nuclear atypia, pleomorphism, and readily detectable mitoses including atypical forms (mean, 25 mitoses per 10 HPF). None of the benign or malignant tumors exhibited neoplastic bone production. The benign and malignant GCTs of soft tissue demonstrated a similar immunohistochemical staining profile to GCT of bone ( 12 tumors examined), exhibiting strong positive staining for CD68 within multinucleated osteoclastlike cells, and focal staining of mononuclear cells for CD68, Ham 56, and smooth muscle actin. All tumors were treated by surgical resection. Follow-up information is available for 15 patients (range, 0-108 months). No benign tumor has recurred or metastasized. Of the four patients with malignant tumors for whom follow-up information is available, one died of metastatic disease at 13 months and one developed a local recurrence at 84 months but is alive, apparently free of disease after additional excisional surgery. Primary GCTs of soft tissue are distinctive neoplasms that, like osseous GCTs, exhibit a wide clinicopathologic spectrum. These neoplasms should be distinguished from other giant cell-rich soft-tissue tumors with which they may be confused.

Conducting an inventory of informal community-based resources for children with physical disabilities: enhancing access and creating professional linkages

This article describes the process involved in conducting a sample inventory of community-based sports, recreation/leisure, and arts resources that include children with physical disabilities in Monroe County, New York. The inventory instrument, Community Resource Inventory for Children with Physical Disabilities, was designed to examine organizational or group capacity to provide activities for children with physical disabilities. The inventory was administered by phone to organizations and groups identified as meeting the definition of a community-based resource. One hundred and six CBR informants were interviewed, each reporting one or two recreational activities provided at their site. The activities included arts, sports, or leisure offerings, with a total of 127 activities identified in the sample. The results of the study support the premise that community-based resources are receptive to providing activities for children with physical disabilities and to potential collaboration with therapists. Numerous barriers exixts, however, including environmental inaccessibility, lack of personnel training, and including environmental inaccesssbility, lack of personnel training, and costs of participation. The results suggest several educational and system-based changes that may promote future collaborative efforts between therapists and community-based organizations.

Grading of spindle cell sarcomas in fine-needle aspiration biopsy specimens

We studied whether histologic criteria for grading sarcomas could be applied to fine-needle aspiration biopsy (FNAB) specimens of adult spindle cell sarcomas, without knowledge of the sarcoma subtype, by reviewing 36 specimens. Grade 1 was assigned for minimal nuclear atypia and overlap, no necrosis, and rare mitotic figures, and grade 2 for moderate nuclear atypia, at least moderate nuclear overlap, appreciable mitotic figures, and necrosis. Severe nuclear atypia distinguished grade 3 from grade 2. A major noncorrelation between FNAB and histologic grades was defined as a misclassification of grade 1 vs grade 2 or 3. FNAB grades assigned were grade 1, 1; grade 2, 25; and grade 3, 10. There was 1 major noncorrelation due to a probable FNAB interpretation error. In 15 of 16 FNAB specimens of grade 2 or 3 sarcomas lacking mitotic figures, necrosis, or both, the nuclear atypia reflected the grade. In the remaining case, the degree of nuclear overlap and necrosis determined the grade. The histologic grading of sarcomas can be applied accurately to most FNAB specimens of spindle cell sarcomas without knowledge of the sarcoma subtype.

Malignant transformation of neurofibromas in neurofibromatosis 1 is associated with CDKN2A/p16 inactivation

Patients with neurofibromatosis 1 (NF1) are predisposed to develop multiple neurofibromas (NFs) and are at risk for transformation of NFs to malignant peripheral nerve sheath tumors (MPNSTs). Little is known, however, about the biological events involved in the malignant transformation of NFs. We examined the CDKN2A/p16 gene and p16 protein in NFs and MPNSTs from patients with NF1. On immunohistochemical analysis, all NFs expressed p16 protein. The MPNSTs, however, were essentially immunonegative for p16, with striking transitions in cases that contained both benign and malignant elements. None of the benign tumors had CDKN2A/p16 deletions, whereas three of six MPNSTs appeared to have homozygous CDKN2A/p16 deletions. Methylation analysis and mutation analysis of CDKN2A/p16 in MPNSTs did not reveal any abnormalities. These results show that malignant transformation of NF is associated with loss of p16 expression, which is often secondary to homozygous deletion of the CDKN2A/p16 gene. The findings suggest that CDKN2A/p16 inactivation occurs during the malignant transformation of NFs in NF1 patients and raises the possibility that p16 immunohistochemistry may provide ancillary information in the distinction of NF from MPNST.

Primary pulmonary sarcoma: a clinicopathologic study of 26 cases

The clinical and pathologic features of 26 primary pulmonary sarcomas were analyzed. Fourteen patients were male and 12 were female; ranging in age from 18 to 75 years (mean, 48 yr). The tumors measured from 0.9 cm in greatest diameter to filling the entire hemithorax. Thirteen tumors were in the left lung and nine in the right lung; one was bilateral, two were in the pulmonary artery, and the location of one tumor was not available. The histologic diagnoses were malignant fibrous histiocytoma (7), synovial sarcoma (6), malignant peripheral-nerve sheath tumor (3), leiomyosarcoma (3), angiosarcoma (2), intimal sarcoma (2), fibrosarcoma (2), and one case of epithelioid hemangioendothelioma. Immunohistochemical and ultrastructural examination supported these diagnoses. Morphologically, the differential diagnosis often included sarcomatoid carcinoma or desmoplastic malignant mesothelioma Patients were treated with surgery, chemotherapy, radiation therapy, or a combination of these. Follow-up was available for 22 patients and ranged from 2 to 183 months (mean, 45 mo). Fourteen patients are free of disease, four died of disease, three are alive with disease, and one died of surgical complications. A variety of sarcomas, especially malignant fibrous histiocytoma and synovial sarcoma, arise within the pulmonary parenchyma. These tumors have the potential to behave aggressively but can be cured by resection, with or without adjuvant therapy. Immunohistochemistry and electron microscopy can be helpful in distinguishing primary pulmonary sarcoma from other tumors in the differential diagnosis.

Chondrosarcoma of the base of the skull: a clinicopathologic study of 200 cases with emphasis on its distinction from chordoma

Conventional chondrosarcoma (CSA) of the skull base is an uncommon neoplasm that can resemble chordoma, and indeed it is misdiagnosed frequently as such. This has important clinical implications, because when treated with similar aggressive treatment strategies, CSA has a much better prognosis than chordoma. In an effort to identify those morphologic and immunohistochemical features that help to identify conventional skull base CSA correctly and to understand its prognosis better, particularly compared with chordoma, when treated with surgery and proton beam irradiation, the authors performed a clinicopathologic analysis of 200 CSAs. The patients ranged in age from 10 to 79 years (mean, 39 years), 87 patients were male and 113 patients were female, and most presented with symptoms related to the central nervous system. Approximately 6% of the tumors arose in the sphenoethmoid complex, 28% originated in the clivus, and 66% developed in the temperooccipital junction. Histologically, 15 tumors (7.5%) were classified as hyaline CSA, 59 (29.5%) as myxoid CSA, and 126 (63%) as mixed hyaline and myxoid CSA. A total of 101 (50.5%) tumors were grade 1, 57 (28.5%) had areas of grades 1 and 2, and 42 (21%) were pure grade 2 neoplasms. The vast majority of patients originated from referring hospitals, and the diagnosis was changed prospectively at our institution to CSA from chordoma in 74 patients (37%). Of the tumors studied immunohistochemically, 96 of 97 (98.9%) stained for S-100 protein, 0 of 97 (0%) stained for keratin, and faint staining for epithelial membrane antigen was seen in 7 of 88 tumors (7.95%). All patients underwent high-dose postoperative fractionated precision conformal radiation therapy with a dose that ranged from 64.2 to 79.6 Cobalt-Gray-equivalents (median, 72.1 Cobalt-Gray-equivalents, given in 38 fractions. The 200 patients had a median follow-up of 63 months (range, 2.1 mos - 18.5 yrs). Tumor control was defined as lack of progression by clinical and radiographic assessment. Based on this definition, there were three local recurrences, and two of these patients died of tumor-related complications. The 5- and 10-year local control rates were 99% and 98% respectively, and the 5- and 10-year disease-specific survival rates were both 99%. In contrast to CSA, the 5- and 10-year survival rates of chordoma have been reported to be approximately 51 % and 35% respectively, and in our institution intensive treatment has resulted in 5- and 10-year progression-free survival rates of 70% and 45% respectively. CSA of the skull base can be distinguished reliably from chordoma, and this distinction is important because skull base CSA has an excellent prognosis when treated with surgery and proton beam irradiation, whereas chordomas have a substantially poorer clinical course despite similar aggressive management.

Hyalinizing spindle cell tumor with giant rosettes: a report of three cases with ultrastructural analysis

We report the light microscopic, ultrastructural appearance and immunohistochemical staining profile of three distinctive soft-tissue tumors recently designated hyalinizing spindle cell tumor with giant rosettes. The tumors occurred in two men, 41 and 54 years old, and one woman, 62 years old. Two tumors arose in the lower extremities and one in the upper arm. Two tumors were resected and measured 3 and 13.2 cm in greatest diameter; a biopsy only was done of the third tumor. Grossly, the tumors had a tan, pink, or white cut surface. The largest tumor exhibited central cystic change. Microscopically, they all displayed similar features and were composed of fibromyxoid regions, with areas of hyalinization in two tumors and focal ossification in one tumor. Scattered throughout each of the tumors were rosette-like structures in which neoplastic cells were arranged around a central collagenous core. Ultrastructurally, the neoplastic cells demonstrated the features of fibroblasts. In all tumors, there was abundant extracellular collagen fibers and in one there were large aggregates of amorphous extracellular external lamina-like material. The center of the rosette-like structures was composed of banded collagen fibers and the cells at the periphery of the rosettes had ultrastructural features similar to the neoplastic spindle cells located elsewhere in the tumor. Immunohistochemically, the tumor cells stained for vimentin. There was focal staining of the widely distributed spindle cells and cells that formed the rosettes for Leu-7, S-100 protein, and CD34. In one tumor, there was faint diffuse staining of the spindle cells for neuron-specific enolase. One tumor (with the amorphous extracellular material) stained for type IV collagen. There was no staining for desmin, muscle actin, smooth muscle actin, keratin, or epithelial membrane antigen. These results demonstrate that hyalinizing spindle cell tumor with giant rosettes is composed of fibroblasts. We did not demonstrate any ultrastructural or immunohistochemical differences between the spindle cells that comprised the majority of the mass and those that surrounded the rosette-like structures. There was no ultrastructural evidence of neural differentiation to explain the focal S-100 protein and Leu-7 staining of the tumor cells.

Proton radiation therapy for chordomas and chondrosarcomas of the skull base

OBJECT

Local tumor control, patient survival, and treatment failure outcomes were analyzed to assess treatment efficacy in 58 patients in whom fractionated proton radiation therapy (RT) was administered for skull base chordomas and chondrosarcomas.

METHODS

Between March 1992 and January 1998, a total of 58 patients who could be evaluated were treated for skull base tumors, 33 for chordoma and 25 for chondrosarcoma. Following various surgical procedures, residual tumor was detected in 91% of patients; 59% demonstrated brainstem involvement. Target dosages ranged from 64.8 and 79.2 (mean 70.7) Co Gy equivalent. The range of follow up was 7 to 75 months (mean 33 months). In 10 patients (17%) the treatment failed locally, resulting in local control rates of 92% (23 of 25 patients) for chondrosarcomas and 76% (25 of 33 patients) for chordomas. Tumor volume and brainstem involvement influenced control rates. All tumors with volumes of 25 ml or less remained locally controlled, compared with 56% of tumors larger than 25 ml (p = 0.02); 94% of patients without brainstem involvement did not experience recurrence; in patients with brainstem involvement (and dose reduction because of brainstem tolerance constraints) the authors achieved a tumor control rate of 53% (p = 0.04). Three patients died of their disease, and one died of intercurrent disease. Actuarial 5-year survival rates were 100% for patients with chondrosarcoma and 79% for patients with chordoma. Grade 3 and 4 late toxicities were observed in four patients (7%) and were symptomatic in three (5%).

CONCLUSIONS

High-dose proton RT offers excellent chances of lasting tumor control and survival, with acceptable risks. In this series all small- and medium-sized tumors with no demonstrable brainstem involvement have been controlled; all such patients are alive. Surgical debulking enhanced delivery of full tumoricidal doses, but even patients with large tumors and disease abutting crucial normal structures benefited.

Extraskeletal myxoid chondrosarcoma of the knee

Extraskeletal myxoid chondrosarcoma is an uncommon neoplasm, accounting for less than 2% of all soft tissue sarcomas. It affects adult males with a median age in the fifth decade at the time of diagnosis. The tumor usually arises in the deep soft tissues, especially in the lower extremities. Patients present with a gradually enlarging mass that may or may not be associated with pain. This report describes a 25-year-old man who initially presented with a 4- to 5-year history of right knee pain and an enlarging mass in the right knee. Evaluation revealed a cartilaginous neoplasm with no evidence of metastatic disease. The tumor was widely excised and an allograft reconstruction was performed. The patient was closely followed with an eventual above the knee amputation for recurrent myxoid chondrosarcoma. At 34 months, retroperitoneal metastases were noted on abdominal CT. The patient underwent a left radical nephrectomy, renal vein thrombectomy and enucleation of the mass in the right kidney, distal pancreatectomy, and splenectomy. The patient received postoperative chemotherapy. Forty-eight months after initial diagnosis, the patient was found to have recurrent abdominal and retroperitoneal lesions. At 64 months, the patient died from complications of extraskeletal myxoid chondrosarcoma.

Hemorrhagic epithelioid and spindle cell hemangioma: a newly recognized, unique vascular tumor of bone

BACKGROUND

Epithelioid vascular tumors of bone are uncommon and include epithelioid hemangioma, epithelioid hemangioendothelioma, and epithelioid angiosarcoma. It is important to distinguish among them because they have significantly different biologic potential and require different forms of therapy. In the current study the authors describe six cases of a distinct benign epithelioid and spindle cell vascular tumor of bone that, because of their unusual morphology, were confused with aggressive vascular neoplasms.

METHODS

Cases were retrieved from the surgical pathology files of the Department of Pathology or from the consultation files of one of the authors. Hematoxylin and eosin stained slides were examined. Immunohistochemistry was performed on two cases and electron microscopy was performed on one case.

RESULTS

The tumors arose in the small bones of the hands and feet and the tibia. Three patients had multifocal bone disease at the time of presentation. Histologically, all lesions were comprised of lobules of spindle cells that grew focally in a fascicular pattern and were associated with abundant hemorrhage. Plump epithelioid cells were intermixed and were present focally in the interlobular areas as well, in which they lined larger, more well developed vascular spaces, often protruding into the vascular lumen in a "tombstone" fashion. Immunohistochemically and ultrastructurally the neoplastic cells had features of endothelium. One case was treated by amputation, one by resection, three by curettage, and one by curettage plus radiation therapy. None of the lesions was locally aggressive nor did any metastasize.

CONCLUSIONS

The authors believe that hemorrhagic epithelioid and spindle cell hemangioma of bone is a histologically benign bone tumor. It should be distinguished from malignant epithelioid vascular tumors of bone, which have metastatic potential and need to be treated more aggressively.

Chondromyxoid fibroma: a tumor showing myofibroblastic, myochondroblastic, and chondrocytic differentiation

Chondromyxoid fibroma (CMF) is a rare primary benign tumor of bone that demonstrates variable histologic features and is often confused with chondrosarcoma. Although the chondroid elements in CMF have been reported to be S-100 protein positive and to have chondrocytic features ultrastructurally, the immunohistochemical and ultrastructural profile of CMF, especially with respect to the peripheral nonchondroid elements, has not been extensively studied. Formalin-fixed, paraffin-embedded tissue from 10 CMFs were stained immunohistochemically with antibodies to vimentin, desmin, muscle actin, smooth muscle actin, S-100 protein, and CD34. Six tumors were also examined ultrastructurally. The chondroid areas showed variable staining for S-100 protein but did not stain for muscle actin or smooth muscle actin. The peripheral areas surrounding the chondroid areas stained diffusely for smooth muscle actin and muscle actin but did not stain for S-100 protein. CD34 highlighted the extensive vascularity that was especially prominent in the peripheral areas; no tumor cells stained for CD34. There was no staining for desmin. Ultrastructural examination showed three different cell types. Some cells showed the classic features of chondrocytes, other cells had the features of myofibroblasts, and the third cell type had the features of both chondrocytes and myofibroblasts ("myochondroblasts"). These findings support the conclusion that CMF is a tumor showing myofibroblastic, myochondroblastic, and chondrocytic differentiation.

Chondrosarcoma of bone: an assessment of outcome

BACKGROUND

The data on 227 patients who had been managed for a chondrosarcoma at one institution were reviewed to determine the nature of the lesions, the predictors of outcome, and whether there were any ways to change the treatment approaches to improve the results.

METHODS

The patients were followed for a mean duration of six years (range, three to twenty-five years). The mean age of the patients was forty-seven years (range, nine to eighty-four years). The most prevalent sites of the tumors were the femur (seventy-eight), the pelvis (fifty-one), and the humerus (thirty-nine). The tumors were divided into two groups according to histological grade. Eighty-six tumors (sixteen atypical enchondromas and seventy grade-1 chondrosarcomas) that were locally destructive but were associated with a low likelihood of metastasis were considered to be low-grade. The remaining 141 lesions, which were locally destructive, potentially metastatic, and capable of causing death, were thought to be high-grade. One hundred and three of these 141 lesions were grade 2, and thirty-eight were grade 3 (eighteen of the thirty-eight were grade 3 only, and twenty were both grade 3 and dedifferentiated). Two hundred and twenty-four patients were managed with resection and a limb-sparing procedure; the remaining three patients had an amputation. Postoperative adjuvant radiation was used for fifty-six patients; chemotherapy, for thirty-five; and both radiation and chemotherapy, for nineteen. Flow cytometric patterns were analyzed for 105 patients.

RESULTS

The patients who had a high-grade tumor were older than those who had a low-grade tumor (mean age [and standard deviation], 50+/-17.0 years compared with 40+/-15.9 years; p < 0.001). Pathological fracture, metastasis, local recurrence, and death were more prevalent in the group that had a high-grade lesion (p < 0.001). Predictors of metastasis and death in that group of patients included local recurrence, a pelvic location of the tumor, a tumor that was more than 100 cubic centimeters in size, a ploidic abnormality (aneuploidy coupled with a high mean DNA index), a histological grade of 3, and a dedifferentiated type of tumor (p < 0.001).

CONCLUSIONS

Although the data are suggestive, with the numbers available for study we could not detect a significant difference in the rates of pulmonary metastasis and death between the patients who had a grade-3 lesion and those who had a grade-3 lesion that was also dedifferentiated. However, the interval between diagnosis and death was 32+/-22.8 months for the patients who had a grade-3 lesion compared with 5+/-3.7 months for those who had a grade-3 lesion that was also dedifferentiated (p < 0.001). Overall, patients who had had a resection with wide margins (margins extending outside the reactive zone) had a longer duration of survival than did those who had had a so-called marginal resection (margins extending outside the tumor but within the reactive zone) or an intralesional resection (margins within the lesion) (p < 0.04). Adjunctive chemotherapy or radiation, or both (which, it must be noted, was used, without a protocol, in a relatively small number of patients), after an intralesional resection, for recurrent disease, or for distant metastasis did not appear to alter the outcome.

Infiltrative subcutaneous malignant fibrous histiocytoma: a comparative study with deep malignant fibrous histiocytoma and an observation of biologic behavior

Malignant fibrous histiocytoma (MFH) is one of the most common soft tissue sarcomas of adulthood. Although it is usually intramuscular and pseudocapsulated, we have recently observed MFHs with extremely infiltrative growth margins, which are predominantly located in the subcutis. These lesions are often associated with incomplete primary surgical excision, the subsequent need for additional surgery or adjuvant therapy, and an increased risk for local recurrence. To further analyze the growth pattern and clinical implication of the subcutaneous infiltrative MFHs, we reviewed a series of 24 subcutis and 21 intramuscular MFHs of the extremities. Morphologically, we defined "infiltrative" as tumor extension along normal tissue planes for a minimum measurable distance of 2 mm from the edge of the main mass. Radiographic findings were correlated with pathologic findings. Of the 24 subcutis MFHs, 83% showed an infiltrative growth pattern, involving 5% to 90% (mean, 51%) of the evaluable margin. Fifty percent of patients with subcutaneous MFH had both an infiltrative growth pattern and positive surgical resection margin on initial resection. Only 25% noninfiltrative subcutaneous MFHs had a positive initial surgical resection margin. Of the 21 intramuscular MFHs, only 5 (24%) had an infiltrative growth pattern that involved 5% to 90% (mean, 40%) of the evaluable margin. One of the five tumors had 90% margin infiltration with multiple positive surgical resection margins. Of 16 noninfiltrative intramuscular MFHs, 3 (19%) had positive resection margins. Magnetic resonance imaging (MRI) and/or computed tomography (CT) scan correctly identified the growth pattern in 87% of subcutaneous and 88% of intramuscular MFHs. Patient follow-up evaluation showed that four (17%) patients with subcutaneous MFHs had resection-proven recurrences, 6 to 57 months after diagnosis. All four of these tumors had infiltrative growth patterns and positive margins on the original surgical resection. There were no local recurrences of the intramuscular MFHs. Two patients of 20 in the infiltrative subcutaneous MFH group and two patients of four in the well-circumscribed subcutaneous MFH group had biopsy-proven metastases, which developed within 5 years after diagnosis. Six patients had metastases in the intramuscular MFH group. A group of MFHs, predominantly subcutaneous, have an extremely infiltrative growth pattern. This growth pattern, documented by radiographic methods and/or light microscopic examination of biopsy specimens, should indicate that a wider margin on initial resection is necessary to entirely excise the lesion. The presence or absence of an infiltrative growth pattern is not predictive of the tumor's metastatic potential.

Subchondral acute inflammation in severe arthritis: a sterile osteomyelitis?

Although arthritis is often associated with synovial inflammation, the osseous changes in inflammatory and degenerative arthritis are principally reactive, and typically lack an acute inflammatory component. We have recently encountered several osteoarticular specimens removed at the time of large joint arthroplasty that have shown a distinctive pattern of subchondral acute inflammation (SCAI) resembling acute bacterial osteomyelitis. These microscopic findings heretofore have not been recognized as a component of the histopathology of arthritis. To determine the frequency of SCAI, we examined slides (mean four per case) from 164 hip arthroplasties performed at one of our institutions in a single year. A total of 10 cases of SCAI, including the 4 original examples (2 humeral head specimens, 2 femoral head specimens) and 6 identified from the slide review are described in this report. Eight patients were female and two were male (ages 54-86 years, mean 70, median 70). All had severe degenerative joint disease, six had rheumatoid arthritis, and three had osteonecrosis. In none was there a clinical or intraoperative suspicion of infection. Cultures of joint fluid or bone were not performed. In all cases, the inflammation was subchondral (within 1.0 cm of the joint surface), and it was frequently associated with subchondral cysts. In osteonecrotic foci, the suppurative inflammation was diffuse within the marrow space, whereas in viable bone it was nodular and vaguely granulomatous. Special stains for organisms were negative. None of the patients was treated with long-term IV antibiotics. There has been no septic loosening of the prostheses at follow-up intervals ranging from 5 to 36 months (mean: 17 months). Our observations, to the best of our knowledge, are novel. Although we cannot definitively exclude bacterial infection as a cause of SCAI, the histologic and clinical features suggest that SCAI likely represents a noninfectious sterile form of inflammation. Subchondral acute inflammation is possibly secondary to synovial fluid insudation into subchondral cancellous bone in the setting of severe osteoarthritis and/or rheumatoid arthritis.

Matrix metalloproteinase digestion of aggrecan in human cartilage tumours

Substantial experimental and clinical evidence suggests that the catabolism of extracellular matrix components is a prerequisite for invasive and metastatic behaviour of solid tumours. Chondrosarcomas are malignant cartilaginous tumours that most commonly arise in bone, and the large aggregating proteoglycan aggrecan is a major component of the extracellular matrix of these tumours. Matrix metalloproteinases (MMPs) have been implicated in tumour invasiveness. The purpose of this study was to determine whether MMPs play a role in aggrecan catabolism in cartilage tumours. In order to detect aggrecan digestion products resulting from in vivo cleavage at the MMP site, protein extracts from human articular cartilage and from various cartilage tumours were analysed by Western blot using an antibody to the FVDIPEN neoepitope generated by MMP cleavage. Examination of cartilage extracts revealed a trend of increasing aggrecan digestion at the MMP site with age. One hyaline chondrosarcoma and three osteochondromas lacked detectable aggrecan fragments with the carboxy terminal FVDIPEN neoepitope. Two osteochondromas gave weak signals. However, all chondrosarcomas with degenerating extracellular matrix or with a myxoid component exhibited strong FVDIPEN immunoreactivity. These results demonstrate that, in contrast to the benign cartilage tumour osteochondroma, human chondrosarcomas contain abundant aggrecan degradation products resulting from cleavage in vivo at the MMP site in the interglobular domain. These data support the concept that MMPs participate in the degradation of extracellular matrix in chondrosarcoma, allowing the neoplastic chondrocytes to escape local confinement, migrate, and invade neighbouring and remote tissues.

Intramuscular myxoma: a clinicopathologic study of 51 cases with emphasis on hypercellular and hypervascular variants

Intramuscular myxoma (IM) is a benign soft-tissue tumor that presents as a deeply seated mass confined to skeletal muscle. Surgical excision is virtually always curative. Recurrence, even after incomplete resection, is exceptional. Intramuscular myxoma is classically described as hypocellular and hypovascular, and is composed of cytologically bland stellate and bipolar fibroblasts separated by abundant extracellular myxoid matrix. What is underemphasized, however, is that IMs often show areas of increased cellularity and vascularity that can lead to a mistaken diagnosis of sarcoma, especially myxofibrosarcoma, low-grade fibromyxoid sarcoma, and myxoid liposarcoma. In this report, we describe the clinicopathologic features of 51 IMs with special emphasis on those that exhibit these "hypercellular regions." The patients included 35 women and 16 men who ranged in age from 27 to 89 (mean 52) years. The tumors measured from 2 to 15 (average 5.6) cm and all had a gelatinous, lobulated cut surface. Histologically, they all demonstrated classic hypocellular, hypovascular regions. Thirty-eight tumors contained areas of relative increased cellularity that occupied from 10 to 80% of the tumor. These foci had increased numbers of cells, more prominent vascularity, and often increased collagen content. The hypercellular regions were not associated with cytologic atypia of the constituent cells, mitotic activity, or necrosis. Follow-up information was available for 32 patients and ranged from 3 to 108 (average 30) months. No tumor recurred or metastasized. Areas of hypercellularity are common in IMs. Their recognition is important to avoid an erroneous diagnosis of sarcoma.

Accuracy of CT-guided needle biopsy of musculoskeletal neoplasms

OBJECTIVE

The purpose of our study was to assess the accuracy of CT-guided biopsy of musculoskeletal neoplasms with respect to technique, anatomic site, and histology.

MATERIALS AND METHODS

During a 3-year period (January 1992 to December 1994), 176 core needle biopsies and 45 fine-needle aspirations were performed under CT guidance on patients with musculoskeletal neoplasms. To assess the accuracy of these procedures, we compared the diagnosis at biopsy with the final diagnosis as determined at the time of definitive treatment of the lesion. All biopsy findings were categorized as a primary malignancy (excluding round cell lesions), round cell lesion, local recurrence, or metastatic carcinoma. In addition, each lesion was analyzed according to which biopsy technique was used, whether frozen tissue section or rapid cytologic evaluation was used, and at which anatomic site the mass was found.

RESULTS

The accuracy for needle biopsy was 93% and that for fine-needle aspiration was 80%. The complication rate for both techniques was less than 1%. Accuracy rates for the four categories of primary malignancy, round cell lesion, local recurrence, and metastatic carcinoma were 87%, 75%, 94%, and 100%, respectively. The mismatch rates were similar in soft-tissue lesions (5/52) and bone lesions (16/169). Diminished accuracy was associated with round cell lesions (20%) and lesions located in the spine or the perivertebral region (20%). Nondiagnostic and insufficient specimens were found in 18 (8%) of the 221 patients. CONCLUSION. CT-guided biopsy of musculoskeletal malignancies is a safe and effective procedure if performed by a team of clinicians, pathologists, and radiologists who possess subspecialty expertise.

CDKN2A gene deletions and loss of p16 expression occur in osteosarcomas that lack RB alterations

Osteosarcomas often suffer mutations of the RB (retinoblastoma) gene, with resultant inactivation of the pRb protein. pRb is one component in a cell-cycle control pathway that includes the p16 (encoded by the CDKN2A gene) and cyclin-dependent kinase 4 (cdk4, encoded by the CDK4 gene) proteins. We therefore sought to determine whether the CDKN2A and CDK4 genes were altered in those osteosarcomas that lacked RB inactivation. Twenty-one osteosarcomas (2 low-grade and 19 high-grade) were evaluated for homozygous deletion of the CDKN2A gene, CDK4 amplification, and allelic loss of the RB gene, as well as for expression of p16 and pRb proteins. Five high-grade osteosarcomas showed loss of p16 expression; four of these had homozygous CDKN2A deletions, and the fifth had a probable deletion obscured by numerous nonneoplastic, p16-immunopositive multinucleated giant cells. Thus, p16 immunohistochemistry may provide a sensitive means for assessing CDKN2A status. Twelve tumors (including the two low-grade osteosarcomas) were immunopositive for pRb, and nine tumors were immunonegative for pRb. Of the five cases with CDKN2A/p16 alterations, none had allelic loss of the RB gene and all expressed pRb, suggesting that each of these tumors had an intact RB gene. None of the tumors showed CDK4 amplification. No alterations were detected in the two low-grade osteosarcomas. This study suggests that CDKN2A is a tumor suppressor inactivated in osteosarcomas that lack RB mutations and that the p16-pRb cell-cycle control pathway is deregulated in a large number of high-grade osteosarcomas.

Primary ovarian rhabdomyosarcoma: a report of 13 cases

Primary ovarian rhabdomyosarcomas were found in 13 patients aged 7 to 79 (mean 37) years who had reported abdominal pain and swelling. Six tumors involved the right ovary, 3 involved the left, 1 involved both, and the laterality was unknown in 3 cases. Four tumors were stage I, 2 were stage II, 4 were stage III, and 2 were stage IV; the stage of 1 tumor is not known. The tumors ranged from 10 to 19.5 (average 16) cm in diameter and had solid sectioned surfaces that varied from yellow to white to pink and from gelatinous to hemorrhagic. Microscopically, 11 tumors were embryonal and 2 were alveolar rhabdomyosarcomas. Follow-up information, available for 11 patients, revealed that 7 died of disease 10 days to 26 months postoperatively; 2 of these patients had stage II disease, 3 had stage III, and 2 had stage IV. Four patients were alive 2 to 9 months postoperatively; 3 had stage I and 1 had stage III disease. These 13 tumors and an additional 10 from the English-language literature are reviewed and the differential diagnosis of ovarian rhabdomyosarcoma is discussed.

Lipoma arborescens of the knee

Lipoma arborescens is a rare intra-articular lesion, characterised by diffuse replacement of the subsynovial tissue by mature fat cells, producing prominent villous transformation of the synovium. The aetiology of this benign condition is unknown. We describe six cases involving the knee, discussing the symptoms, diagnosis and treatment.

Atypical decubital fibroplasia: a series of three cases

We report three cases of atypical decubital fibroplasia (ADF), a benign, reactive pathologic process that develops in the skin and subcutaneous tissue of immobilized or debilitated patients. Two patients were immobilized, one wheelchair bound, and one bedridden. The third patient frequently lay over the affected area. Two were male, one female, ages 49, 66, and 89 (mean 68 years old). Each patient presented with a subcutaneous mass, one with focal surface ulceration, present for 5 months, 6 months, and 12 months (mean 7.7 months). The locations included back, lateral thigh (over greater trochanter), and lateral chest wall. No other lesions were present, and none had recurrences. Histologically, atypical decubital fibroplasia is characterized principally by dermal and subcutaneous tissue involvement with fibrinoid necrosis, reactive fibrosis, and focal myxoid change with surrounding more cellular zones of prominent reactive neovascularization including granulation tissue and ectatic vessels with reactive atypical fibroblasts and fat necrosis. Other findings include hyalinization of vessel walls, fibrin thrombi, red blood cell extravasation, hemosiderin deposition, and acute and chronic inflammation. Although the changes are predominantly deep, involving the dermis, subcutaneous tissue and skeletal muscle, the overlying epidermis may ulcerate. Recognition of atypical decubital fibroplasia is of paramount importance, for it may be misinterpreted as a sarcoma, both clinically and histologically.

Osteoid osteoma: the uniquely innervated bone tumor

Osteoid osteomas are benign bone-forming tumors that despite their small size (<2.0 cm) characteristically produce severe nocturnal bone pain that is relieved by aspirin. This typical clinical presentation is virtually unique among bone tumors. Histologically, osteoid osteomas are circumscribed nodules of woven bone and osteoid with prominent osteoblastic rimming (the nidus), surrounded by thickened cortical and trabecular bone and loose fibrovascular tissue (the reactive zone). Prostaglandins mediate the pain of osteoid osteomas, but there have been few studies of their innervation. We investigated 34 osteoid osteomas using a streptavidin immunohistochemical technique and a panel of antibodies to neural and neural-associated antigens (phosphorylated neurofilament, neurofilament, and S-100 protein). Whenever possible, sections of the nidus and the reactive zone were stained. As controls, we stained other bone tumors that can be painful, including 10 osteoblastomas, 5 osteosarcomas, 6 giant cell tumors, 4 chondroblastomas, 3 aneurysmal bone cysts, and 6 cases of fibrous dysplasia. Twenty-five osteoid osteomas contained phosphorylated neurofilament-, neurofilament-, and/or S-100-positive nerve fibers in the reactive zone around the nidus and/or in the nidus. The nerve fibers were larger and more abundant in the reactive zone than in the nidus, and they were occasionally visible on hematoxylin- and eosin-stained slides on retrospective review. The smaller nerve fibers within the nidi were never identified, even after extensive review of those slides. In the nine cases in which nerve fibers were not identified, the sampled tissue consisted only of nidus. None of the control "bone tumors" contained detectable nerve fibers within their substance or in the adjacent peripheral bone. The nerve supply of osteoid osteoma seems unique among bone tumors, and it might serve as a marker in diagnostically difficult cases.

Individualizing management of aggressive fibromatoses

PURPOSE

To examine prognostic indicators in aggressive fibromatoses that may be used to optimize case-specific management strategy.

METHODS AND MATERIALS

One hundred and seven fibromatoses presenting between 1971 and 1992 were analyzed. The following treatment modalities were utilized: (a) surgery alone for 51 tumors; (b) radiation alone for 15 tumors; and (c) radiation and surgery (combined modality) for 41 tumors. Outcome analysis was based on 5-year actuarial local control rates.

RESULTS

Control rates among surgery, radiation therapy, and combined modality groups were 69%, 93%, and 72%. Multivariate analysis identified age < 18 years, recurrent disease, positive surgical margins, and treatment with surgery alone as predictors for failure. Patients treated with surgery alone had control rates of 50% (3 of 6) for gross residual, 56% for microscopically positive margins, and 77% for negative margins. Radiation and surgery resulted in rates of 59% for gross residual, 78% for microscopically positive margins, and 100% (6 of 6) for negative margins. For recurrent vs. primary tumors, control was achieved in 48% vs. 77%, 90% vs. 100% (5 of 5), and 67% vs. 79% in the Surgery, Radiation, and Combined modality Groups, respectively. Patients presenting with multiple disease sites tended to have aggressive disease. A radiation dose-control relation to > 60 Gy was seen in patients with unresected or gross residual disease. Of the patients, 23 with disease involving the plantar region had a control rate of 62%, with significantly worse outcomes in children.

CONCLUSIONS

These results are consistent with those found in the relevant literature. They support primary resection with negative margins when feasible. Radiation is a highly effective alternative in situations where surgery would result in major functional or cosmetic defects. When negative surgical margins are not achieved in recurrent tumors, radiation is recommended. Perioperative radiation should be considered in other high-risk groups (recurrent disease, positive margins, and plantar tumors in young patients). Doses of 60-65 Gy for gross disease and 50-60 Gy for microscopic residual are recommended. Observation may be considered for primary tumors with disease remaining in situ when they are located such that progression would not cause significant morbidity. Although plantar lesions in children may represent a group at high risk for recurrence or aggressive behavior, the greater potential for radiation-induced morbidity in this group must also temper its use. Given the inconsistent nature and treatment response of this tumor, it is fundamental that treatment recommendations should be made based on the risk:benefit analysis for the individual patient, dependent on tumor characteristics and location, as well as patient characteristics and preferences.

Expression of transforming growth factor-beta (TGF-beta) isoforms in osteosarcomas: TGF-beta3 is related to disease progression

BACKGROUND

Transforming growth factor-beta (TGF-beta) is a multipotent growth factor affecting development, homeostasis, and tissue repair. In addition, increased expression of TGF-beta has been reported in different malignancies, suggesting a role for this growth factor in tumorigenesis.

METHODS

Using immunohistochemistry, the expression, prevalence, and distribution of TGF-beta isoforms were evaluated in 25 high grade human osteosarcomas. The Cox proportional hazards models and Kaplan-Meier curves were calculated correlating disease free survival with TGF-beta expression.

RESULTS

Expression of one or more TGF-beta isoforms was found in all the osteosarcomas. Immunoreactivity for TGF-beta1 and TGF-beta3 generally was stronger than for TGF-beta2. The cytoplasm of the tumor cells showed stronger staining than their surrounding extracellular stroma. Most notably, osteoclasts showed strong to intense staining for all three isoforms. In 11 of 25 specimens angiogenic activity was noted with staining of multiple small vessels in the tumor stroma. Expression of TGF-beta3, but not of TGF-beta2 or TGF-beta1, related to disease progression, such that there was a statistically significant decrease in the disease free interval as the immunoreactivity for TGF-beta3 increased.

CONCLUSIONS

All osteosarcomas expressed TGF-beta in the cytoplasm of the tumor cells as well as in their extracellular stroma. The presence of TGF-beta in the endothelial and perivascular layers of small vessels in the tumor stroma suggests angiogenic activity of this growth factor. The expression of TGF-beta3 was correlated strongly with disease progression (P = 0.027). These data suggest that increased expression of TGF-beta isoforms, especially TGF-beta3, may play a role in osteosarcoma progression.

Mucin deposits within inguinal hernia sacs: a presenting finding of low-grade mucinous cystic tumors of the appendix. A report of two cases and a review of the literature

Two male patients, both 41 years of age, presented clinically with a typical inguinal hernia. The herniorrhaphy specimens were found on routine pathologic examination to contain abundant mucin that was focally organizing and was devoid of associated epithelial cells. Both cases were seen in consultation because of uncertainty as to the nature of the process. The possibility that the mucin might represent spread from an appendiceal mucinous cystic tumor led to the investigation of the appendix and in both cases such a tumor was discovered. The widespread involvement of the peritoneum that is characteristic of pseudomyxoma peritonei was absent in each case. These cases represent one of the many "surprise" findings that may be encountered in hernia sac specimens and one of the many problematic pathologic manifestations that may be associated with low-grade mucinous neoplasms of the appendix. Although this phenomenon is described in the literature, experience with our two cases indicates that it may still pose a significant diagnostic challenge.

Infantile hemangioendothelioma of the ovary: a monodermal teratoma or a neoplasm of ovarian somatic cells?

Vascular tumors of the female genital tract are uncommon, and only a few cases have been reported in the ovary. We describe herein, an unusual tumor of the ovary: infantile hemangioendothelioma (cellular hemangioma of infancy) in a newborn. The tumor consisted of well-formed blood vessels and proliferating endothelial cells that were arranged in solid cordlike structures. The tumor permeated the ovarian stroma and entrapped normal ovarian follicles. By immunohistochemistry the neoplastic cells expressed factor VIII, CD34, and alpha smooth-muscle actin, and ultrastructurally they had the features of endothelial cells that were focally associated with pericytes. We examined simple sequence repeat (SSR) polymorphic markers in the tumor tissue, as well as in the patient's and parents' blood. The informative SSR markers were found to be identical in the tumor and in the patient's somatic cells. We suggest that the tumor described herein is a congenital infantile hemangioendothelioma arising from ovarian parenchymal cells rather than a teratoma originating from germ cells. A similar morphologic lesion has been described recently in the ovary and interpreted as monodermal teratoma composed of vascular tissue.

Solitary fibrous tumor of soft tissue: a report of 15 cases, including 5 malignant examples with light microscopic, immunohistochemical, and ultrastructural data

We describe 15 soft tissue solitary fibrous tumors (SFTs) occurring in patients 24 to 78 years old (average, 50.6 yr). Ten tumors were benign and arose in the head and neck area (three tumors), thigh (two), vulva (two), upper arm (one), lower leg (one), and retroperitoneum (one). Five tumors were histologically malignant and arose in the thigh (two), abdominal wall (one), buttock (one), and retroperitoneum (one). All of the tumors were grossly well circumscribed. The benign tumors measured from 2 to 10 cm (average, 4.8 cm) and the malignant ones from 3 to 5.5 cm (average, 4.3 cm) in greatest diameter. Microscopically, the benign tumors showed areas of hypercellularity with variable amounts of collagenous and myxoid stroma; one had amianthoid fibers. The malignant tumors were composed of cytologically atypical cells enmeshed in a collagenous or myxoid extracellular matrix. Ultrastructural study of three benign and three malignant tumors showed fibroblastic differentiation; one benign tumor showed myofibroblastic differentiation. Immunohistochemically, all of the tumors examined were immunoreactive for vimentin, and seven of nine were positive for CD34, including all of the malignant ones. There was focal staining for muscle actin in two benign tumors and for Leu-7 in one benign tumor; there was no staining for cytokeratin, desmin, S-100 protein, epithelial membrane antigen, or smooth muscle actin in any of the examined tissues. Follow-up was available for eight patients for 6 to 21 months (average, 12 mo). No tumor recurred locally or metastasized. The SFTs reported herein support the experiences of others who recently described these tumors in the somatic soft tissues. In addition, our series highlights the occurrence of malignant SFTs in the soft tissues. SFTs should be separated from other spindle cell sarcomas, with which they can be confused.

Osteocalcin and osteonectin immunoreactivity in the diagnosis of osteosarcoma

Osteosarcomas (OSAs) can be difficult to distinguish histologically from tumors with significantly different biologic potentials and treatment protocols. The correct diagnosis of OSA relies on identification of malignant osteoblasts that are capable of producing neoplastic bone. To determine the use of immunohistochemistry for the diagnosis of OSA, 106 tumors from the Massachusetts General Hospital and the University of Vermont were immunostained with monoclonal antiosteocalcin (OC) and antiosteonectin (ON) antibodies. They included 42 OSAs, 25 non-bone-forming sarcomas, 24 other malignant tumors including lymphomas, carcinomas, and melanomas, and 15 benign bone tumors. Cytoplasmic staining with OC showed 70% sensitivity and 100% specificity, while staining with ON showed 90% sensitivity and 54% specificity for bone-forming tumors, consistently staining cell types other than osteoblasts. Of the OSAs, 83% demonstrated matrix staining with one or both antibodies, whereas dense collagen was negative for both antibodies in all tumors. We conclude that tumor cell cytoplasmic staining with monoclonal OC may be helpful in distinguishing OSAs from other malignancies, and staining of extracellular matrix for OC and ON antibodies concurrently may help distinguish bone matrix from dense collagen.

Angiomyofibroblastoma of the vulva with sarcomatous transformation ("angiomyofibrosarcoma")

We report on a locally recurrent vulvar tumor in an 80-year-old woman that we believe represents the first example of malignant transformation of an angiomyofibroblastoma. The tumor was predominantly a typical angiomyofibroblastoma, composed of epithelioid or oval cells with eosinophilic cytoplasm that tended to cluster in small groups and around blood vessels. These areas merged imperceptibly with a high-grade sarcoma that resembled a myxoid malignant fibrous histiocytoma. The tumor cells in the benign areas were diffusely immunoreactive for vimentin; many cells were positive for smooth muscle actin, and focal positivity for muscle actin and desmin was observed. The tumor cells in the sarcomatous areas were diffusely positive for vimentin, but negative for smooth muscle actin, muscle actin, and desmin. No staining for keratin, S-100 protein, or CD34 was noted. Ultrastructural examination of the sarcomatous area showed that the cells had the features of fibroblasts. All previously reported cases of angiomyofibroblastoma have exhibited banal histologic features and have behaved in a benign fashion. This case shows that these tumors may rarely be associated with a malignant component, and the designation "angiomyofibrosarcoma" may be appropriate in such cases.