Establishment and characterization of a novel chordoma cell line: CH22

Chordoma is a rare primary malignant bone tumor and there exist only a few established human chordoma cell lines. The scarcity of robust chordoma cell lines has limited the ability to study this tumor. In this report, we describe the establishment of a novel chordoma cell line and characterize its in vitro and in vivo behaviors. The tumor tissue was isolated from a patient with recurrent chordoma of the sacrum. After 6 months in culture, the chordoma cell line, referred here as CH22, was established. Microscopic analysis of two-dimensional culture confirmed that the CH22 cells exhibited a typical vacuolated cytoplasm similar to the well-established chordoma cell line U-CH1. Electron microscopy showed cohesive cells with numerous surface filopodia, pockets of glycogen and aggregates of intermediate tonofilaments in cytoplasm. Three-dimensional culture revealed that the CH22 cells could grow and form clusters by day 8. The MTT assays demonstrated that, compared with sensitive osteosarcoma cell lines, CH22 cells were relatively resistant to conventional chemotherapeutic drugs. Western blotting and immunofluorescence analysis confirmed that the CH22 cells expressed brachyury, vimentin, and cytokeratin. Finally, histological analysis of CH22 xenograft tumor tissues demonstrated the appearance of physaliphorous cells and positive staining of brachyury, cytokeratin, and S100. By CT and MRI, imaging xenografts showed the typical appearances seen in human chordomas. These findings suggest that the established novel human chordoma cell line CH22 and its tumorigenecity in SCID nude mice may serve as an important model for studying chordoma cell biology and the development of new therapeutic modalities.

Use of electron microscopy in core biopsy diagnosis of oncocytic renal tumors

The distinction between oncocytoma and chromophobe renal cell carcinoma, important clinically, may be challenging, especially as the tissue sample size decreases. Ancillary studies can be helpful, although subject to interpretation and sample variability. The aim of this study was to examine the value of electron microscopy in differentiating between oncocytoma and chromophobe renal cell carcinoma on formalin fixed paraffin embedded needle core biopsies. Twenty renal needle core biopsies were evaluated. Despite formalin fixation and paraffin embedding, the classic ultrastructural features of these neoplasms were retained, revealing 80% sensitivity and 100% specificity by initial work-up.

Tolerance to limb tissue allografts between swine matched for major histocompatibility complex antigens

Transplantation of limb tissue allografts would greatly expand the realm of reconstructive surgery. However, the toxicity of chronic immunosuppression has adversely tilted the risk-benefit balance for clinical transplant. In this study, a procedure was sought to achieve host tolerance to limb tissue allografts through matching of the major histocompatibility complex (MHC) antigens between donor and host swine using only a 12-day course of cyclosporine. Massachusetts General Hospital (MGH) miniature swine were used as a large animal model with defined MHC, and musculoskeletal grafts from the donor hind limb were transplanted heterotopically to the recipient femoral vessels. Allografts from MHC-mismatched donors treated with cyclosporine (n = 4) were rejected in less than 6 weeks by gross inspection and histologic sections. Allografts from MHC-matched, minor antigen mismatched donors not treated with cyclosporine (n = 4) were rejected between 9 and 12 weeks. Allografts from similarly matched donors treated with 12 days of cyclosporine (n = 7) showed no evidence of rejection until sacrifice between 25 and 47 weeks. Thus allograft tolerance was achieved between MHC-matched swine using a limited course of cyclosporine. Demonstration of limb tissue allograft survival in a large animal model without long-term immunosuppression represents an important step toward clinical transplantation.

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.

TOLERANCE TO MUSCULOSKELETAL ALLOGRAFTS WITH TRANSIENT LYMPHOCYTE CHIMERISM IN MINIATURE SWINE1

BACKGROUND

Although transplantation of musculoskeletal allografts in humans is technically feasible, the adverse effects of long-term immunosuppression subject the patient to high risks for correcting a non-life-threatening condition. Achieving immunologic tolerance to musculoskeletal allografts, without the need for chronic immunosuppression, could expand the clinical application of limb tissue allografting. Tolerance to musculoskeletal allografts has been accomplished previously in miniature swine in our laboratory. Although stable, mixed chimerism has been suggested as the mechanism underlying long-term tolerance in a rat limb model, the mechanism of this tolerance induction has not been established. This report explores the possible relationship between hematopoietic chimerism and tolerance to musculoskeletal allografts in swine.

METHODS

Twelve miniature swine underwent vascularized musculoskeletal allograft transplantation from histocompatibility complex (MHC) matched, minor antigen-mismatched donors. Eight animals received a 12-day coprse of cyclosporine, one of which was excluded due to subtherapeutic levels. Four recipients were not immunosuppressed. Serial biopsies to assess graft viability and flow cytometry to assess chimerism were performed. Donor and third-party skin grafts were placed on recipients with surviving allografts greater than 100 days to validate tolerance.

RESULTS

Both groups developed early peripheral chimerism, but this chimerism became undetectable by postoperative day 19 in the cyclosporine group and by day 13 in the control group. Animals receiving cyclosporine developed permanent tolerance to their allografts, whereas those not receiving cyclosporine rejected their allografts in 6-9 weeks. Animals demonstrating tolerance to their bone allografts also demonstrated prolonged donor skin graft survival.

CONCLUSIONS

Induction of tolerance to musculoskeletal allografts can be achieved in the MHC matched swine. Although hematopoietic chimerism is present in the immediate postoperative period, persistent, long-term chimerism does not seem to be necessary for maintenance of such tolerance.

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.

Mesenchymal tumors and tumor-like lesions of the female genital tract: a selective review with emphasis on recently described entities

The diverse mesenchymal tumors and tumor-like lesions that occur within the female genital tract include a number of lesions that have only been recently characterized and others about which there is new information. In this group are the aggressive angiomyxoma, angiomyofibroblastoma, and cellular angiofibroma. Criteria for the distinction of these lesions are reviewed, as are the pathologic features of prognostic significance in assessing smooth muscle tumors of the vulva. The diagnostic problems that the epithelioid variant of smooth muscle tumors, both benign and malignant, may pose when they occur in various areas of the genital tract are discussed, particularly with regard to problems encountered in the ovary, a site where the diagnosis often is not considered. Recent information expanding the morphologic spectrum of fibroepithelial polyps of the genital tract is presented, and important non-neoplastic entities, including nodular fasciitis and the postoperative spindle cell nodule, are reviewed. Mesenchymal tumors of the various types seen in the soft tissues may be encountered anywhere in the female genital tract and have been the subject of particular recent interest in the ovary; issues relevant to differential diagnosis are reviewed.

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.

NHE-RF, a merlin-interacting protein, is primarily expressed in luminal epithelia, proliferative endometrium, and estrogen receptor-positive breast carcinomas

NHE-RF, a regulatory cofactor for NHE (Na(+)-H(+) exchanger) type 3, interacts with ion transporters and receptors through its PDZ domains and with the MERM proteins (merlin, ezrin, radixin and moesin) via its carboxyl terminus. Thus, NHE-RF may act as a multifunctional adaptor protein and play a role in the assembly of signal transduction complexes, linking ion channels and receptors to the actin cytoskeleton. NHE-RF expression is up-regulated in response to estrogen in estrogen receptor-positive breast carcinoma cell lines, suggesting that it may be involved in estrogen signaling. To further understand NHE-RF function and its possible role in estrogen signaling, we analyzed NHE-RF expression in normal human tissues, including cycling endometrium, and in breast carcinomas, tissues in which estrogen plays an important role in regulating cell growth and proliferation. NHE-RF is expressed in many epithelia, especially in cells specialized in ion transport or absorption, and is often localized to apical (luminal) membranes. NHE-RF expression varies markedly in proliferative versus secretory endometrium, with high expression in proliferative (estrogen-stimulated) endometrium. Furthermore, estrogen receptor status and NHE-RF expression correlate closely in breast carcinoma specimens. These findings support a role for NHE-RF in estrogen signaling.

Isochromosome 7q in adult Wilms' tumors: diagnostic and pathogenetic implications

Wilms' tumors affecting adults are rare and are thought to have a worse prognosis than similar stage tumors in the pediatric population. To understand these tumors better, the authors reviewed their multi-institutional experience in a series of nine lesions diagnosed as Wilms' tumors in adults. In addition to histologic and immunohistochemical examination, they performed cytogenetic analysis and fluorescence in situ hybridization. On review, four cases were reclassified: two "blastema only" as Ewing's sarcoma/primitive neuroectodermal tumor and the other two as clear cell sarcoma of soft parts and sarcoma not otherwise specified (NOS). Of the remaining five cases, three exhibited biphasic histology and two were triphasic. In this group, there were three women and two men, and patient age ranged from 17 to 37 years (median age, 26 years). Tumor size was large and ranged from 10 to 31 cm (median tumor size, 12.5 cm). Histologically, the tumors showed the typical features of Wilms' tumors with varying amounts of blastema (n = 5), epithelium (n = 5), and stroma (n = 2). No tumors contained anaplasia, and persistent renal blastema was not identified in the non-neoplastic kidney in any specimen. All tumors were positive for cytokeratins (CK7, n = 3; pankeratin, n = 5), and one tumor was weakly positive for CD99 (0-13). Molecular analysis including dual color fluorescence in situ hybridization (all tumors), and cytogenetic analysis (n = 2) disclosed the presence of isochromosome 7q in three of five tumors whereas all tumors were diploid with respect to chromosome 12. Follow-up data ranged from 6 to 133 months (median follow-up, 82 months) with progression in only one patient who had stage IV disease with lymph node and lung metastases at presentation. The authors conclude that adult Wilms' tumor has been overdiagnosed. Most "blastema-only" tumors in adults are not Wilms' tumors, and in an adult, biphasic morphology should be the minimum criteria for their diagnosis. Using strict diagnostic criteria, adult Wilms' tumors have a relatively favorable prognosis. The characteristic findings of isochromosome 7q, lack of trisomy or tetrasomy for chromosome 12, and absence of persistent renal blastema suggest that the pathogenesis of Wilms' tumors in adults may be different than in the pediatric population. These genetic features may be helpful in distinguishing adult Wilms' tumors from other primary renal tumors.

Is anti-h-caldesmon useful for distinguishing smooth muscle and myofibroblastic tumors? An immunohistochemical study

Misinterpretation of positive staining of antibodies to desmin, smooth muscle actin, and muscle actin as representing smooth muscle differentiation in the context of a spindle cell tumor is not uncommon. Anti-h-caldesmon is a promising novel immunohistochemical reagent for more specific smooth muscle differentiation. We studied 72 tumors (11 leiomyosarcomas, 26 malignant fibrous histiocytomas [MFHs], 11 fibromatoses, 11 cellular cutaneous fibrous histiocytomas [CCFHs], 5 malignant peripheral nerve sheath tumors, 4 synovial sarcomas, and 4 cases of nodular fasciitis), the reactive myofibroblastic response in 5 cases of acute cholecystitis, and the desmoplastic response surrounding 5 invasive breast carcinomas. Tissues were examined for expression of h-caldesmon, desmin, smooth muscle actin, and muscle actin. Diffuse staining for h-caldesmon was present only within the leiomyosarcomas. Focal staining for h-caldesmon involving less than 1% of lesional cells was present in 3 of 26 MFHs and 1 of 11 CCFHs. There was overlap in staining for the other "myoid" markers in all of the lesions that contained myofibroblasts. Anti-h-caldesmon seems to be a reliable marker of smooth muscle differentiation, and its inclusion in a panel of myoid immunohistochemical reagents should allow distinction of smooth muscle and myofibroblastic tumors.

Lipid-rich diffuse malignant mesothelioma: a case report

An 80-year old man presented with shortness of breath and was found to have a large right pleural effusion. Cytology of the pleural fluid showed atypical papillary clusters of epithelioid cells. Multiple white-yellow nodules studding the pleural surfaces were seen at thoracoscopy, and biopsies showed solid and papillary clusters of large epithelioid cells with abundant cytoplasm filled with clear vacuoles. Special stains and electron microscopic findings indicated that the tumor was a diffuse malignant mesothelioma with numerous intracytoplasmic lipid vacuoles. Fat stain may be useful at time of frozen section for a pleural-based tumor with vacuolated cells, and the presence of lipid vacuoles in a pleural-based tumor does not exclude diffuse malignant mesothelioma.

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.

High resolution imaging of transitional cell carcinoma with optical coherence tomography: feasibility for the evaluation of bladder pathology

Significant challenges regarding patient morbidity and mortality remain in the management of transitional cell carcinoma (TCC). Among the most important of these challenges is the inability to identify early neoplastic changes and to assess the degree of tumour invasion into the bladder wall in vivo. Optical coherence tomography (OCT) has been recently developed to provide in situ, high resolution, catheter/endoscope based imaging. This study explored the feasibility of OCT for the evaluation of bladder pathology. Both in vitro and in vivo studies were performed. In vitro imaging of pathological human bladder was performed and compared with normal specimens and histopathology. In vivo imaging of normal rabbit bladder was also performed with our current catheter/endoscope based systems. In the in vitro studies, OCT was able to delineate normal microstructure of the bladder, such as the mucosa, submucosa and muscularis layers. This was in contrast to specimens of invasive carcinoma, where a disruption of the normal bladder wall architecture was seen. The in vivo experiment demonstrated current limitations of the catheter/endoscope based systems and provided valuable information for developing an improved system for bladder imaging. The ability of OCT to delineate microstructure of the bladder wall suggests feasibility for endoscopic based imaging. In particular, there is a potential role envisioned for OCT in the management of TCC, identifying pre-malignant states and the depth of tumour invasion.

Long-term results of combined modality therapy in primary bone lymphomas

PURPOSE

To report the Massachusetts General Hospital experience in the management of patients with primary bone lymphoma (PBL) treated with combined modality therapy (CMT).

METHODS AND MATERIALS

Records from 37 eligible patients were reviewed. Two patients were treated with complete resection of the tumor, while 35 patients underwent radiation therapy with a median total dose of 54 Gy (range 38.35-66.5). All patients received combination chemotherapy, which contained doxorubicin in 33 cases. We compared the current data with our previous experience in patients treated with local measures only.

RESULTS

Actuarial disease-free survival (DFS) at 5 and 10 years is 78% and 73%, respectively, while overall survival (OS) is 91% and 87%, respectively. No local failures were seen. Pathologic fracture at presentation influenced DFS (p = 0.005) and OS (p = 0.017) adversely. OS was compromised in patients older than 60 years (p = 0.059) and DFS in patients with pelvic primaries (p = 0.015). CMT was associated with improved DFS (p = 0.0008) and OS p = 0.0001) compared to our historical controls. Ten patients (27%) developed complications requiring orthopedic procedures following completion of therapy at a median of 25.5 months (range 4-228).

CONCLUSION

Patients with PBL have a favorable outcome with CMT, which appears superior to radiation therapy alone. Late complications can be seen, especially in weight-bearing bones.

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.

Immunohistochemical survey of p16INK4A expression in normal human adult and infant tissues

p16INK4A is a cell cycle inhibitor that is commonly inactivated in human tumors and tumor cell lines. Despite its importance in human neoplasia, the normal pattern of p16 expression remains largely unknown. Therefore, we analyzed the immunohistochemical localization of p16 in all human organs and demonstrated that cellular p16 expression is highly selective. In adults, proliferative endometrium, breast ductal epithelium, squamous and tubal metaplastic epithelium of the uterine cervix, esophageal squamous epithelium, salivary glands, and antral gastric glands all strongly express the protein. p16 is also widely expressed in endocrine glands, including Langerhans cells in the pancreas and anterior pituicytes and Leydig and Sertoli cells in testis. Within each tissue, however, p16 expression does not correlate with cellular proliferation or maturation. In infants, p16 staining was limited to thymic Hassall's corpuscles, occasional thymic lymphocytes, and only rare pancreatic epithelial cells. Therefore, increased expression of p16 in adult tissues, as in mouse tissues, may reflect a role of p16 in cellular senescence. Restriction of p16 expression in infants to the thymus, the only organ committed to early senescence, is also consistent with such a role. Documentation of the pattern of p16 expression in normal tissues will contribute to our understanding of the normal function of this protein and to interpretation of potentially altered p16 expression in human tumors.

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.

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.

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.

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.

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.

Primary angiosarcoma of the ovary: a report of seven cases and review of the literature

Seven primary ovarian angiosarcomas were diagnosed in 7 patients 20 to 32 (mean 26) years of age. The most common clinical presentation was abdominal pain and distention. Three tumors were in the right ovary and 3 in the left; one was bilateral. Four tumors were Stage I and 3 Stage III. The tumors were brown and hemorrhagic, ranging in maximum dimension from 6 to 13 (average 10) cm. Microscopically, 5 tumors were pure angiosarcomas and 2 were associated with a dermoid cyst. Follow-up information ranging from 2 months to 9 (average 3.6) years was available for 5 patients. Three patients, all with Stage III disease, died of tumor (1 with a pure angiosarcoma, 2 with tumors arising in a dermoid cyst) 2, 15, and 30 months postoperatively. Two patients with Stage I disease and follow-up data were alive and healthy 5.5 and 9 years postoperatively. The differential diagnosis of these tumors is discussed and the literature reviewed.

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.

Fibromatosis of soft tissue type involving the female genital tract: a report of two cases

Two cases of soft tissue-type fibromatosis of the female genital tract are described. One involved the vulva of a 19-year-old woman, and was approximately 6.0 cm in greatest dimension and had a rubbery consistency with a gray-white, whorled cut surface. Microscopically, it had infiltrating borders and extended to the ischio-rectal region. All gross tumor was resected. There was no evidence of recurrent disease 6 years later. The other tumor involved primarily the ovary of a 20-year-old woman. It was 24 cm in greatest dimension and infiltrated the mesentery, psoas muscle, and iliac vessels. The tumor was resected along with the sigmoid colon and the patient was free of disease 3 months later. Fibromatosis of the female genital tract, histologically identical to the soft tissue lesion and distinct from so-called "ovarian fibromatosis," should be included in the differential diagnosis of low-grade spindle cell lesions of this region.

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.

Nodular fasciitis of the vulva: a study of six cases and literature review

We report six cases of histologically typical nodular fasciitis that each presented as a vulvar soft tissue mass. The diagnosis of nodular fasciitis had not been considered by the referring pathologist in any of the five consultation cases. The patient's ages ranged from 7 to 51 years (mean 34). The lesion was confined to the labia in the four cases in which a specific site was noted. The masses ranged from 1.5 to 3.5 cm (mean 2.2) in maximal dimension. All of them were locally excised, and the resection margins were involved in each case. In addition to the typical features of nodular fasciitis, a noteworthy finding in two of the six cases was the presence of cleftlike spaces lined by plump synovial-like cells. Follow-up ranged from 3 months to 7 years (mean 24 months). A local recurrence developed in one patient at 4 months and was reexcised; there have been no recurrences in any other case. The literature contains only five additional examples of vulvar nodular fasciitis. Although all were pathologically typical, the diagnosis was often not considered, evidently because of the unusual location. Awareness that nodular fasciitis may occur in the vulva and the features that allow its distinction from other mesenchymal "tumors" occurring at this site will facilitate its correct diagnosis.

Synovial sarcoma of the vulva: a report of two cases

We report two cases of synovial sarcoma arising in the vulva. The patients were 30 and 37 years old and presented with a painless mass that was interpreted clinically as a cyst. The tumors were 2.0 and 1.2 cm in greatest diameter. Histologically, they were composed of epithelial cells forming solid nests and gland-like and papillary structures surrounded by spindle-shaped cells. Immunohistochemically, the epithelial cells stained for cytokeratin and the spindle-shaped cells for vimentin. Ultrastructurally, the epithelial cells had prominent intercellular junctions and narrow microvilli and were separated from the spindle-shaped cells by a basal lamina. The spindle-shaped cells were closely apposed with focal intercellular contacts. One tumor recurred locally 3.5 years after excision, but the patient was alive and well 1 year after a re-excision and radiation therapy. The other patient was alive and well 4 years after an excision. These tumors are the first reported examples of synovial sarcoma arising in the vulva.

Collagenous fibroma (desmoplastic fibroblastoma): a report of seven cases

We report the clinical features, light microscopic and ultrastructural appearance, and the immunohistochemical profile of seven benign fibrous tumors recently designated as desmoplastic fibroblastoma. The tumors occurred in four women and three men, who ranged in age from 41 to 76 years (mean, 53 yr). The tumors were located in the left thigh, right shoulder, right upper arm, left forearm, right neck, posterior neck, and foot and measured from 1.5 to 8 cm (mean, 4.6 cm) in greatest diameter. Four tumors were located in the subcutaneous tissue, two tumors were intramuscular, and one tumor involved the subcutaneous tissue and adjacent skeletal muscle. Six patients underwent a simple excision; one patient underwent a wide excision of the tumor. Grossly, the tumors were well circumscribed with a white to tan-white, bulging cut surface. Microscopically, they all displayed similar features and were composed of widely separated stellate- or spindle-shaped cells embedded in a hypovascular fibrous or fibromyxoid stroma. No mitotic figures, calcifications, or necrosis were identified. Five tumors were well demarcated, and two tumors had focally infiltrating margins. Ultrastructural examination performed on two cases showed that the tumor cells had features of fibroblasts and myofibroblasts. Immunohistochemical examinations performed on six cases showed that all of the tumors were diffusely positive for vimentin. One tumor showed diffuse staining for smooth muscle actin, and two tumors were focally positive for that antibody. One tumor showed diffuse staining for muscle actin, and another one was focally positive. Two tumors demonstrated diffuse faint staining for S100 protein. There was no staining for desmin, keratin, or CD34. Follow-up information was available in four cases and ranged from 1 to 60 months (average, 24 mo). No tumor recurred. Although the term desmoplastic fibroblastoma has been applied to this neoplasm, we think that the name collagenous fibroma is more appropriate for these tumors.

Smooth-muscle tumors of the vulva. A clinicopathological study of 25 cases and review of the literature

The clinical and pathological features of 25 smooth-muscle tumors of the vulva were analyzed. The patients ranged in age from 17 to 67 (mean, 37.6) years; two were pregnant. Twenty-three tumors were 1.5 to 16 (mean, 5.2) cm in greatest dimension; the size of two tumors was unknown. Microscopic examination showed that 16 tumors were circumscribed, six had focally infiltrative margins, and the margins could not be evaluated in three tumors. Fourteen tumors were composed mainly of spindle cells; two of these tumors had prominent myxoid stroma. Seven tumors were predominantly epithelioid and had a prominent hyalinized or myxoid stroma; often the cells had a plexiform pattern. Four tumors contained an approximately equal number of epithelioid and spindle cells. Ten tumors had mild, nine moderate, and six severe cytologic atypia. Mitotic figures ranged from 0 to 10 (average, 1.8) per 10 high-power fields (hpf). Immunohistochemically, all the tumors stained for one or more muscle markers. Thirteen of 17 tumors were positive for estrogen receptors, and 16 of 18 were positive for progesterone receptors. Follow-up information ranging from 1 month to 19 years (average, 5 years) was available in 19 cases. Four tumors recurred locally, and one patient with recurrent tumor died of metastases 7 months after the initial operation. We propose an expanded criteria to distinguish between leiomyomas and leiomyosarcomas of the vulva. Tumors that manifest three or all of the four following features should be considered sarcomas: > or = 5 cm in greatest dimension, infiltrative margins, > or = 5 mitotic figures per 10 hpf, and moderate to severe cytologic atypia. Those that have only one of these characteristics should be diagnosed as leiomyoma, and those that exhibit only two of these features should be considered benign but atypical leiomyomas. The sarcomas should be excised with widely negative margins; the leiomyomas and the atypical leiomyomas should be excised conservatively, with long-term, careful follow-up.

Angiomyofibroblastoma of the vulva and vagina

Nine vulvar and three vaginal angiomyofibroblastomas from patients 23 to 71 years of age (mean, 46 yr) were analyzed. The tumors were well circumscribed and ranged from 0.9 to 11 cm (average, 4.7 cm) in maximal dimension. On microscopic examination, they had hypercellular and hypocellular areas. The neoplastic cells were spindle-shaped, plasmacytoid, or epithelioid; a variable number were binucleated or multinucleated cells. A focal storiform pattern was present in one tumor, and, in one tumor, the neoplastic cells formed a collar around a central area of dense collagen. There was no significant nuclear atypia, and there was less than one mitotic figure per 10 high-power fields. The tumors contained small- to medium-sized blood vessels, which were characteristically thin walled and, occasionally, ectatic and branching. The stroma was edematous, separated collagen fibers and contained a variable number of inflammatory cells, especially lymphocytes and mast cells. Three vulvar tumors contained a variable amount of fat. Ultrastructural study of three tumors showed intracytoplasmic, dilated, rough endoplasmic reticulum, moderate numbers of pinocytotic vesicles, and numerous filaments without dense bodies; rare intercellular rudimentary junctions were identified. Eleven of 11 tumors were immunoreactive for vimentin, 11 of 12 for desmin, three of 11 for muscle actin, one of 12 for smooth muscle actin, and four of 12 for CD34. There was no staining for factor XIIIa, keratin, S100 protein, Leu-7, glial fibrillary acidic protein, or CD68. Follow-up revealed no recurrences or metastases. Angiomyofibroblastoma is a distinctive benign tumor that arises most commonly in the vulva and vagina and has a diverse histologic and immunohistochemical profile.

Chondroid lipoma, a tumor of white fat cells. A brief report of two cases with ultrastructural analysis

Chondroid lipoma is a recently described variant of lipoma with unusual morphologic features. Although classified as a fatty neoplasm, its phenotype is uncertain because it has not been determined whether cartilage is a real component or only simulated by light microscopy and whether the adipocytes demonstrate white or brown fat differentiation, issues that can be resolved only by electron microscopy. We present two cases of chondroid lipoma that ultrastructurally showed abundant intracytoplasmic lipid and glycogen and numerous pinocytotic vesicles, characteristic of white adipocytes. These findings support the conclusion that these tumors are composed solely of fat without true cartilage differentiation.

Alveolar soft-part sarcoma of the female genital tract: a report of nine cases and review of the literature

Nine alveolar soft-part sarcomas of the female genital tract (four previously reported) occurred in patients 14-38 (mean 29) years of age. The most common clinical presentation was abnormal uterine bleeding. Two tumors were located in the vagina, three in the cervix or lower uterine segment, three in the uterine corpus, and one in the broad ligament. The tumors were solid and well circumscribed, ranging in maximum dimension from 1 to 9.8 (average 3.6) cm and had the characteristic histologic features of alveolar soft-part sarcoma. Granules that were diastase resistant and positive by periodic acid-Schiff (PAS) were present in all the tumors, and PAS-positive, diastase-resistant crystals were present in eight of them. Follow-up information ranging from 9 months to 17 years (average 62 months) was available for all the patients. One patient died of metastatic disease 25 months after diagnosis; eight other patients had uneventful follow-up periods ranging from 9 months to 17 years (average 67 months). The differential diagnosis of these tumors is discussed and the literature reviewed.

Lipomatous hemangiopericytoma. A histologic, ultrastructural and immunohistochemical study of a unique variant of hemangiopericytoma

We report three cases of a unique, previously undescribed soft tissue tumor composed of mature adipocytes and hemangiopericytomatous areas, for which we propose the term lipomatous hemangiopericytoma. The tumors occurred in adults and were located in the sinonasal area, the soft tissue of the shoulder, and the retroperitoneum. The tumors ranged in size from 4 to 10 cm in greatest diameter and grossly were solid and ranged from tan to yellow. Histologically, they were composed of a variable admixture of benign lipomatous and hemangiopericytomatous components. Immunohistochemically, they stained with antibodies to vimentin and not to alpha-smooth-muscle actin, muscle-specific actin, desmin, S-100 protein, glial fibrillary acidic protein, epithelial membrane antigen, or keratin. Ultrastructurally, the cells constituting the hemangiopericytomatous areas had the features of pericytes, and no lipoblasts or transitional forms between lipocytes and pericytes were found. The histologic differential diagnosis of this neoplasm includes spindle-cell lipoma, angiolipoma, liposarcomas, tumors showing smooth muscle and adipocytic differentiation, and hemangiopericytoma infiltrating fat. Because of the small number of cases and the limited follow-up, we cannot be certain of their biologic behavior, although we expect that they are benign. Lipomatous hemangiopericytoma represents a distinctive pathologic entity that should be recognized and studied further.

The neuropathology of Williams syndrome. Report of a 35-year-old man with presenile beta/A4 amyloid plaques and neurofibrillary tangles

OBJECTIVE

To study neuropathologically Williams syndrome in a 35-year-old patient.

METHODS

Sections from multiple regions of the brain were examined with luxol fast blue and hematoxylineosin staining, and selected sections were stained with the silver impregnation technique (Bielschowsky technique) and Congo red. In addition, immunohistochemistry with monoclonal antibodies against glial fibrillary acidic protein, beta/A4 amyloid, paired helical filaments, and phosphorylated tau protein was performed on cortical, hippocampal, amygdaloid, and basal ganglian sections.

RESULTS

No specific macroscopic or microscopic abnormalities were recognized that are specific for Williams syndrome. The histopathologic examination did, however, demonstrate the presence of Alzheimer-type changes, including beta/A4 amyloid-containing senile plaques and scattered neurofibrillary tangles in neocortex and medial temporal lobe structures (entorhinal cortex, CA1 area of the hippocampus, and amygdala). Plaques were most numerous in the amygdala (7/mm2) and in the entorhinal cortex (4/mm2). Neurofibrillary tangles were less numerous (< 1/mm2), except in the hippocampus, where approximately 2/mm2 were found.

CONCLUSIONS

To our knowledge, ours represents the first neuropathologic description of a patient with Williams syndrome. Although Williams syndrome is usually sporadic, familial cases have been reported along with candidate chromosomal loci. If our findings are confirmed in additional patients with Williams syndrome, they may provide clues to other factors that are important in the pathogenesis of senile plaques (with beta/A4 amyloid deposition) and neurofibrillary tangles.

Fatal intracerebral hemorrhage following thrombolytic therapy of embolic myocardial infarction in unsuspected infective endocarditis

Cerebral hemorrhage occurs in 0.2% of patients under the age of 60 years treated with thrombolytic therapy for acute myocardial infarction. A case of fatal cerebral hemorrhage following TPA therapy for myocardial infarction due to probable coronary artery embolism during unsuspected native valve infective endocarditis is reported.

Flow cytometric DNA analysis of adenocarcinomas of the vermiform appendix. Brief report

The DNA ploidy status and S-phase fraction of eight adenocarcinomas of the vermiform appendix diagnosed in Iceland during 1974-1990 were analyzed by flow cytometry. Four cases were classified as Dukes' stage B2 and four cases as Dukes' stage D. Seven tumors were diploid and one was aneuploid. The DNA aneuploid tumor was the only one which metastasized outside the abdominal cavity. The S-phase fraction in general was low. The results of this study do not indicate any significant correlation between ploidy status and clinical behavior.

Cholecystectomy and colorectal carcinoma: a total-population historical prospective study

The relationship between cholecystectomy and colorectal cancer in the Icelandic population was analyzed in a historical prospective study. A total of 3,425 individuals (857 males and 2,568 females) who underwent cholecystectomy during a 26-yr period (1955-1980) were followed for 8-33 yr. The risk of colonic cancer in Icelandic males increased significantly 11 yr or more after operation (relative risk, 2.73; 95% confidence interval, 1.25-5.19). This is the only study that shows a significantly increased risk of colonic cancer in males only. In spite of this increased risk, regular screening for colonic cancer in Icelandic males would probably not be warranted, since almost 70% of the males are 70 yr old or older at the time of diagnosis.

Adenocarcinoma of the vermiform appendix. A population study

We report seven cases of adenocarcinoma of the vermiform appendix occurring in Iceland during 1974-1989. The patients ranged in age from 25-83 years, mean age 55.1 years. There were five males and two females. Five had mucinous adenocarcinoma, two had adenocarcinoma. Four patients presented with symptoms and signs of acute appendicitis and all had surgically resectable disease. Three of these patients were alive with no evidence of disease four months, two years and 15 years after presentation; one death of disease occurred seven years after ileocecal resection. In three cases, the clinical presentation was that of metastatic adenocarcinoma of unknown origin. Of these patients two were diagnosed at autopsy and one after appendectomy for perforated appendicitis. Survival in this group was six weeks, three months and twelve months, respectively. In none of our patients was the diagnosis made preoperatively and no tumors were found in appendices removed incidental to other intra-abdominal operations. The incidence of adenocarcinoma of the vermiform appendix in Iceland during 1974-1989 was approximately 0.2 cases/100.000/year.

The accuracy of death certificates. Implications for health statistics

The death certificate is an important source of data on disease incidence, prevalence and mortality. It should therefore be as accurate and complete as possible. Death certificates from 433 autopsied hospital patients were reviewed and matched against the results of post-mortem examinations. Significant discrepancies between the two documents were observed in 50% of patients. In 25%, the immediate cause of death was incorrectly stated on the certificate, having been assigned to a different organ system in the majority of those cases. In 33%, there was disagreement on major disease other than the immediate cause of death. In 9%, the death certificate was signed before the autopsy was performed. The extent of disagreement was largely independent of whether the certificate was signed before or after the autopsy. We conclude that: (1) there is a significant discrepancy between autopsy diagnoses and entries on death certificates; (2) disagreement is not due to unavailability of autopsy data at the time of completion of the certificate; (3) death certificates should be completed or amended utilizing data gained at autopsy.