Lipomatous hemangiopericytoma: a rare variant of hemangiopericytoma that may be confused with liposarcoma

We describe the clinicopathologic features and biologic behavior of 16 cases of histologically benign hemangiopericytoma containing a variable amount of mature fat as an intrinsic part of the neoplasm. These so-called lipomatous hemangiopericytomas occurred primarily in men (12 men and 4 women) with a mean age of 54 years (range, 33-74 years). All occurred in deep soft tissue and had an average size of 10 cm when first detected. All were characterized by a relatively sharp border and typical histologic features of hemangiopericytomas, including oval to round cells surrounding a sinusoidal and staghorn vasculature often with perivascular hyalinization. Mature fat varied in amount but usually occupied approximately one quarter to three quarters of the area of tumor. Mitotic activity was low, with more than half the cases having no mitotic activity. Five cases showed moderate nuclear atypia. In four cases, the pericytic regions had sclerotic zones. In contrast to liposarcoma, neither lipoblasts nor isolated atypical hyperchromatic cells within mature fat, as are seen in well-differentiated liposarcoma, were present. Immunohistochemistry performed in four cases showed factor XIIIa in tumor cells and an intricate pattern of immunoreactivity around cells for type IV collagen. CD34 and smooth-muscle actins were identified in two of four cases. Follow-up in seven cases showed no recurrences or metastases within the follow-up period of 1 to 7 years. Because these lesions are located in deep soft tissue and contain large amounts of mature fat, they could be mistaken for well-differentiated liposarcomas in limited biopsy material, although the distinction is easily made in examining the entire specimen. The lipomatous hemangiopericytoma represents yet another example of a bimodal mesenchymal tumor containing mature fat and raises the question of whether a common cytogenetic abnormality can explain the emergence of two clonal populations in this hybrid tumor.

The trefoil gene family are coordinately expressed immediate-early genes: EGF receptor- and MAP kinase-dependent interregulation

The trefoil gene family of mucus cell-secreted proteins is a critical mediator of gastrointestinal mucosal restitution. Transcription of trefoil genes is induced during mucosal repair, but the regulatory mechanisms involved are unknown. Mice deficient in the intestine-specific peptide intestinal trefoil factor (ITF), in which colonic restitution is lethally impaired, showed reduced expression of the gastric trefoil genes SP and pS2, suggesting that trefoil peptides may individually regulate transcription of the entire family. In gastric cell lines, the trefoils were shown to act in a manner suggestive of immediate-early genes capable of auto- and cross-induction through cis-acting regulatory regions. Trefoil-mediated transcriptional regulation required activation of the Ras/MEK/MAP kinase signal transduction pathway. EGF receptor (EGF-R) activation was also necessary for trefoil auto- and cross-induction, and both spasmolytic polypeptide (SP) and ITF stimulation of gastric cell lines led to phosphorylation of EGF-R. Nevertheless, ITF and ITF-thioredoxin cell surface binding at 4 degrees C colocalized not with EGF-R, but with CD71, which is found in clathrin-coated pits, suggesting that integration of trefoil peptide responses may occur after internalization. As EGF-R expression is itself strongly induced after mucosal damage, the trefoil/EGF-R relationship may be pivotal in the generation and maintenance of the mucosal repair phenotype.

Sinonasal malignant lymphomas: a distinct clinicopathological category

Sinonasal lymphomas represent a distinct subset of extranodal head and neck lymphomas. While sinonasal lymphomas are relatively rare in Western countries, in Asian populations they are the second most frequent group of extranodal lymphomas, after gastrointestinal lymphomas. With advances in immunohistochemistry, these lymphomas have been separated into B-cell, T-cell, and most recently into natural killer (NK) cell phenotypes. The B-cell phenotype is typically located in the paranasal sinuses and has a slight predominance in Western countries. The T/NK-cell phenotype is the most common in Asian and South American countries. These tumors are typically located in the nasal cavity and have an aggressive, angioinvasive growth pattern that often results in necrosis and bony erosion. Thus, sinonasal lymphomas have been included in the past with other destructive malignant and benign lesions under the descriptive and nonspecific name lethal midline granuloma. Patients are classically in the sixth to eighth decades, with a 2:1 male-to-female ratio. The prognosis is generally better than that of nodal-based lymphomas of similar histologic grade. Treatment is a combination of local irradiation and chemotherapy with an anthracycline-based regimen.

Chemotherapy and P-glycoprotein expression in chondrosarcoma

Chondrosarcomas are alleged to be resistant to chemotherapy. A retrospective review of our experience primarily with dedifferentiated chondrosarcomas treated with chemotherapy was performed to reevaluate the efficacy of chemotherapy for this tumor. There were 18 patients: 14 stage IIB and four stage III. Seventeen patients had dedifferentiated chondrosarcoma. The median age at diagnosis was 57 years. Fourteen of the patients underwent wide excision of the tumor, two underwent amputation, and two had no surgery. The femur and the pelvis were the most common locations of the primary tumor. Chemotherapy for 11 of the patients consisted of cisplatin and doxorubicin. Survival was analyzed with the Kaplan-Meier method; the median survival was 12 months. The hypothesis that chondrosarcomas express P-glycoprotein was tested. Expression of P-glycoprotein was evaluated by immunostaining with use of the C494 and C219 antibodies on 41 benign and malignant cartilage tumors, six of which were from the patients in the chemotherapy group. Immunostaining revealed that 37 of 41 cartilage tumors expressed P-glycoprotein. The rate of survival of patients with high-grade chondrosarcoma treated with chemotherapy is poor. P-glycoprotein expression is common in benign and malignant cartilage lesions. The lack of response to chemotherapy may be related to the expression of P-glycoprotein.

Primary synovial chondromatosis of the temporomandibular joint with suspected traumatic etiology. Report of a case

Synovial chondromatosis (SC) of the temporomandibular joint (TMJ) is a rare disease that is characterized by the development of nodules of cartilage within the synovial connective tissues of articulating joints. Reports of extracapsular TMJ SC are rare. A case is presented of primary SC of the TMJ with extension to the pterygoid plates, with a suspected traumatic etiology. The differences between primary and secondary SC are discussed.

Extraskeletal mesenchymal chondrosarcoma of the rectus sheath

Mesenchymal chondrosarcomas (MSCs) are a rare form of chondrosarcoma which usually arise in bone. Extraskeletal chondrosarcomas constitute a minority (14-25%) of MSCs. We describe the imaging features of an extraskeletal mesenchymal chondrosarcoma that arose from the rectus abdominus muscle.

Olfactory neuroblastoma and other round cell lesions of the sinonasal region

Sixty-nine round cell lesions of the sinonasal region (22 olfactory neuroblastomas [ONBs], 17 malignant lymphomas, nine Ewing's sarcomas [ES], nine rhabdomyosarcomas, three sinonasal undifferentiated carcinomas, five malignant melanomas, and four pituitary adenomas) were studied in an attempt to define the differential diagnostic capabilities of antibody to MIC2 and bcl-2 in paraffin-embedded tissue in the distinction of these lesions. In addition, antibody to p53 was applied in each case to define the incidence of p53 positivity among these various tumor types. Each of the ES cases was MIC2 positive; each of the other cases was MIC2 negative. Positivity for bcl-2 was confined to two cases, one of them a malignant lymphoma (85% of cells positive) and one an ONB (5% of cells positive). Small numbers of scattered p53-positive cells appeared in the majority of cases studied, without regard for the specific tumor type; only a single case, a malignant lymphoma, showed a majority (approximately 90%) of p53-positive cells. These results indicate that the MIC2 antibody is a useful method by which to distinguish ES from a variety of other round cell lesions that may be encountered in the sinonasal region. The practical applications of antibody to bcl-2 and p53 seem to be much more limited; by contrast, neither bcl-2 positive cells nor abundant p53 cells identified by immunohistochemical analysis seemed to be frequent findings in any of the tumor types studied. Although ONBs have been included with the peripheral primitive neuroectodermal tumors for classification purposes, these tumors diverge from the ES/primitive neuroectodermal tumor family in that they do not seem to share either the MIC2 positivity or the t(11;22) chromosomal translocation that typify the ES/primitive neuroectodermal tumor family of lesions. Although bcl-2 positivity has been associated with a light microscopic finding of an unfavorable histologic pattern in retroperitoneal neuroblastomas, it does not seem that bcl-2 positivity in ONB will select for a clinically distinctive subset of patients.

Inflammatory myofibroblastic tumor of the larynx. A clinicopathologic study of eight cases simulating a malignant spindle cell neoplasm

BACKGROUND

Inflammatory myofibroblastic tumors of the larynx are uncommon lesions that easily may be misinterpreted as malignant epithelial or mesenchymal spindle cell neoplasms.

METHODS

Eight cases of laryngeal inflammatory myofibroblastic tumors were identified from the files of the Otolaryngic Tumor Registry--Armed Forces Institute of Pathology. Clinical records and follow-up were available in all cases. The light microscopic features (hematoxylin and eosin and special histochemical stains) were evaluated in all cases; immunohistochemical analysis was performed in the seven cases with available paraffin blocks; in four cases ultrastructural analysis was done.

RESULTS

The patients included five males and three females ranging in age from 19-69 years (median, 59 years). Presenting symptoms included hoarseness, dysphonia, or rapidly progressive stridor with the duration of symptoms ranging from 10 days to 4 months. The most common site of involvement was the true vocal cord. The lesions appeared as polypoid or pedunculated masses. Histologically, the cellularity of the lesions varied, consisting of spindle-shaped to stellate cells with no consistently discernible growth pattern, in a fibromyxoid stroma that included a mixed inflammatory cell infiltrate. Features suggesting a malignant cellular infiltrate were not present. The spindle-shaped cells had consistent immunoreactivity with vimentin, muscle specific actin, and smooth muscle actin. Ultrastructurally, intracytoplasmic microfilaments were identified. In seven of the patients, conservative but complete excision of the lesion was curative; these patients have been free of disease over periods ranging from 12 to 36 months. In one patient, the lesion recurred twice over a 2-year period and ultimately required a total laryngectomy. This patient died of unrelated causes.

CONCLUSIONS

Inflammatory myofibroblastic tumors of the larynx are unusual benign proliferative lesions. Conservative surgical management is advocated and is curative. Recurrence is rare, but metastases disease or death attributable to these lesions is not.

Biliary cystadenoma and cystadenocarcinoma: clinical-imaging-pathologic correlations with emphasis on the importance of ovarian stroma

PURPOSE

To evaluate cross-sectional imaging in the distinction of biliary cystadenoma from cystadenocarcinoma and in the determination of the presence of ovarian stroma.

MATERIALS AND METHODS

In 34 patients, radiologic studies and specimen photographs and descriptions were reviewed retrospectively without knowledge of the patient group. Histologic features were reviewed without knowledge of the radiologic findings and analyzed for epithelial and stromal components. Correlation was made between the radiologic findings, gross morphologic features, internal fluid characteristics, and histologic features.

RESULTS

The 34 patients had 27 biliary cystadenomas, 22 with ovarian stroma, and seven cystadenocarcinomas, four with ovarian stroma. Gross morphologic and imaging features suggestive of biliary cystadenocarcinoma included internal septation and nodularity. Septation without nodularity was seen only in biliary cystadenoma. Nonbilious fluid was the only feature associated with the presence of ovarian stroma but was not distinguishable on images.

CONCLUSION

Imaging studies accurately reflect the nodularity and septation seen grossly to distinguish biliary cystadenoma and cystadenocarcinoma but do not allow distinction of the presence or absence of ovarian stroma.

Perineurioma

Perineurioma is a rare, probably benign peripheral nerve sheath neoplasm. Perineurial cell origin is most efficiently demonstrated immunohistochemically by positivity for epithelial membrane antigen and negativity for S-100 protein and Leu 7.

Bulbous nasal tip: an anatomical and histological evaluation

The operative management of the bulbous nasal tip is a challenging and unsolved problem. Surgical alteration often leads to disappointing postoperative results. Surgical options for the soft tissue range from tip defatting and scoring of the dermis to no soft-tissue removal at all. The goal of this study was to determine anatomically and histologically the exact nature of the nasal tip soft tissue. Forty-two tissue specimens were obtained from 23 patients undergoing nasal surgery. These specimens were stained with standard hematoxylin and eosin stain and a combined Mallory trichrome and elastic stain and examined under light microscopy by a pathologist. Qualitative assessment of the tissue types present demonstrated that collagenous fibrous tissue was abundant. Skeletal muscle was present in significant amounts and in some cases made up the majority of the subdermal tissue. The adipose tissue component was less than expected.

MIC2 detection in tumors of bone and adjacent soft tissues

The diagnosis of Ewing's sarcoma has been based classically in large part on the exclusion of other similar small round-cell tumors by light microscopic and histochemical criteria. This study was undertaken to explore the use of a recently developed immunohistochemical stain directed against the glycoprotein p30/32MIC2 antigen (the gene product of MIC2), as a diagnostic tool and as a probe for the examination of potential interrelationships among the putative members of the family of peripheral primitive neuroectodermal tumors. Fifty-six small round-cell tumors of bone were selected for study from the files of the Armed Forces Institute of Pathology and Rhode Island Hospital; all tissues had been formalin fixed and paraffin embedded. Nine of 10 Ewing's sarcomas were MIC2 positive, as were 2 of 3 atypical Ewing's sarcomas (small round-cell tumors that diverged from the classic pattern of Ewing's sarcoma by exhibiting a greater degree of cytologic atypia and pleomorphism), and 7 of 8 Askin tumors of the thoracopulmonary region. Ten of 11 mesenchymal chondrosarcomas, 1 primitive neuroectodermal tumor of bone, 10 small cell osteosarcomas, 10 malignant lymphomas, and 3 sarcomas of bone (not additionally subclassified) were negative. The finding of MIC2 positivity in the majority of Ewing's sarcomas and Askin tumors provides additional support for earlier proposals (based on a shared cytogenetic abnormality, among other criteria) that these lesions be considered members of the same family, the peripheral primitive neuroectodermal tumors. The present study, drawing on archival and current case material (including decalcified and undecalcified specimens), indicates that neither the specimen age nor the application of any of a variety of decalcification solutions appears to adversely influence MIC2 staining of paraffin-embedded tissues. This suggests that this antibody has use in retrospective and prospective studies. The rare occurrence of false negative (in the case of Ewing's sarcoma) and positive results in tumors other than peripheral primitive neuroectodermal tumors (as in 1 of the mesenchymal chondrosarcomas) suggests that MIC2 staining should not be relied on as the sole criterion for identification or exclusion of Ewing's sarcomas and related tumors.

Hepatobiliary cystadenoma and cystadenocarcinoma. A light microscopic and immunohistochemical study of 70 patients

Fifty-two hepatobiliary cystadenomas and 18 hepatobiliary cystadenocarcinomas were drawn from the files of the Armed Forces Institute of Pathology and Rhode Island Hospital and studied in an attempt to correlate light microscopic features of the tumors with immunohistochemical and follow-up data. The cystadenoma patients ranged in age from 2 to 87 years at the time of initial diagnosis (mean, 45 years). All the cystadenomas were multilocular with benign cuboidal to columnar epithelium, and 44 (85%) had densely cellular spindle cell ("ovarian-like") stromata; 96% were female. Fifty-one cystadenomas were macrocystic lesions, typically lined by mucinous epithelium; one of the benign lesions was a serous cystadenoma (microcystic adenoma) reminiscent of the more commonly encountered pancreatic lesion of the same name. The cystadenocarcinoma patients ranged in age from 24 to 90 years at the time of first diagnosis (mean, 59 years); eight patients (44%) were male. All but one of the lesions were multilocular with malignant in situ (one case) or invasive tubulopapillary (15 cases), solid (one case), or adenosquamous (one case) epithelial components. Areas of preexisting benign cystadenoma were found in six (33%), an observation suggesting that benign lesions may evolve into malignant ones in some patients. Most cystadenomas and cystadenocarcinomas arose in the liver, a few in the extrahepatic biliary system (including the gallbladder). On follow-up, the cystadenoma patients in general were successfully treated by surgical excision of the lesions in toto; patients treated by subtotal resection often had persistent symptomatic disease. Four cystadenocarcinoma patients died of their tumors; another two patients were alive with persistent disease at last follow-up. In both the benign and the malignant lesions, most tumor cells were positive on immunohistochemical staining with antibodies to cytokeratin, epithelial membrane antigen, and carcinoembryonic antigen; scattered chromogranin-positive cells also appeared in a few tumors of both types. Immunohistochemistry did not yield a diagnostic immunoprofile to distinguish cystadenoma from cystadenocarcinoma or from other epithelial lesions arising within the abdominal cavity. At least two types of cystadenocarcinoma exist, one developing exclusively in female patients, usually accompanied by an "ovarian-like" stroma, which follows an indolent course; and the other, lacking the distinctive cellular stroma, seen in males, follows a more aggressive course and is more likely to result in the patient's death from tumor. It remains an open question whether the cystadenocarcinomas lacking a mesenchymal stroma, which arise in women, will follow the same aggressive course as similar lesions arising in men.

Skeletal-extraskeletal angiomatosis. A clinicopathological study of fourteen patients and nosologic considerations

We reviewed the consultation files of the ARmed Forces Institute of Pathology for 1951 through 1989 and identified fourteen patients who had had skeletal-extraskeletal angiomatosis. Skeletal-extraskeletal angiomatosis was defined as a benign vascular proliferation involving the medullary cavity of bone and at least one other type of tissue. The age of the patients at the time of initial biopsy ranged from nine months to sixty-nine years (average, twenty-two years; median, ten years). Ten of the patients were male and four were female. The presenting signs and symptoms were highly variable; they included pain (four patients), a mass noted at birth (three patients), a painless mass that developed after birth (two patients), both pain and a mass (one patient), a localized deformity of the thoracic spine (one patient), and anemia associated with chronic bleeding of the gastrointestinal tract (one patient); in this last patient, skeletal lesions subsequently were found and biopsied. Skeletal-extraskeletal angiomatosis was an incidental finding in the remaining two patients. Multiple bones were involved in thirteen of the fourteen patients. Histologically, three patterns of lesion could be identified: cavernous lymphangioma (six patients), cavernous hemangioma (six patients), and arteriovenous hemangioma (two patients). Five of the patients died (three of sepsis associated with persistent lesions of angiomatosis and two of unrelated causes); eight of the patients survived but had residual disease, and one survived and had no evidence of residual disease.

Intra-abdominal desmoplastic small round cell tumor of the peritoneum in a young man

The desmoplastic small round cell tumor (DSRCT) has a predilection for involvement of the peritoneal surfaces of young adult men. The tumor has an extremely poor prognosis: despite aggressive therapy the patients usually die of disease within the first 2 years following diagnosis. The present report details the pathologic features of a pelvic tumor, which proved to be a DSRCT, arising in a previously healthy 24-year-old man. The light microscopic features were typical of a DSRCT--the tumor cells were small and round, had inconspicuous cytoplasm, and were grouped into distinctive islands and cords that were dispersed in a fibrous stroma. The immunohistochemical features were likewise characteristic of DSRCT in that the tumor cells were positive for cytokeratin, vimentin, epithelial membrane antigen, and desmin. Ultrastructurally, the tumor cells were distinguished by an abundance of intercellular junctions, cytoplasmic lipid droplets, cytoplasmic intermediate filaments, and an absence of surface microvilli. Recognition of this tumor type is important in view of both its clinical features (extremely poor prognosis despite therapy) and its potential to shed some light on the nature of the family of lesions that has traditionally been classified by light microscopists as small round cell tumors.

Giant cell tumor of the thoracic spine: MR appearance

The MR features of a giant cell tumor that predominantly involved the posterior elements of a thoracic vertebra are presented. This extradural neoplasm compressed and displaced the spinal cord. The tumor had low to intermediate signal on short-repetition-time images and predominantly high signal on long-repetition-time images. It showed mild heterogeneous enhancement with gadopentetate dimeglumine.

Surface-based hemangiomas of bone. A review of 11 cases

The surface-based hemangioma of bone is an uncommon cause of periosteal- or cortical-based lesions. The files of the Armed Forces Institute of Pathology were searched for lesions diagnosed as cortical hemangioma or periosteal hemangioma received between the years 1950 and 1990; 11 cases with follow-up results were identified. The 11 patients ranged in age from 11 to 31 years of age at the time of initial symptoms (average, 21 years; mean, 23 years). Sixty percent of the patients were male and 40% were female. Skeletal sites of involvement included the tibia (45%), the fibula (36%), the femur (9%), and the ulna (9%). Seventy percent of patients complained initially of pain (duration, two months to five years), whereas 30% reported pain and a mass at the time of initial diagnosis (duration, six months to two years). On plain film radiographs, eight lesions showed localized cortical thickening, two showed cortical erosion, and one had a permeative/destructive pattern. Bone scans showed solitary lesions with increased uptake in all 11 patients. The range of histologic types of cortical hemangioma included cavernous (six cases), arteriovenous (three cases), venous (one case), and pyogenic granuloma type (one case). Clinically, the majority of cases were diagnosed as osteoid osteomas; primary pathologic diagnoses included hemangioma (27%) and cortical sclerosis (18%). Persistent complaints were reported in three patients after intralesional biopsy; no recurrences were reported after en bloc excision.

Hepatic sarcoidosis. Clinicopathologic features in 100 patients

The patterns of hepatic injury were studied in 100 patients with a diagnosis of sarcoidosis and clinical evidence of liver disease that led to diagnostic liver biopsy. Granulomas were present in all patients; they occupied from < 1% to > 90% of the total volume of tissue examined and were most often located in the portal/periportal region. In none of the 100 cases were infectious organisms identified by special stains, culture, or serology. In 99% of cases, these granulomas were noncaseating; in one of the 100 cases central caseation was noted. In addition to the granulomas present in all biopsies, three broad categories of histologic change were found: cholestatic (58%), necroinflammatory (41%), and vascular (20%). Among those with cholestasis, 19 patients had bile duct lesions similar to primary biliary cirrhosis, whereas another 13 had a pattern of periductal fibrosis reminiscent of primary sclerosing cholangitis. In 37 patients with chronic cholestasis, a decrease in the number of bile ducts (ductopenia) was noted. Twelve patients had an acute cholangitis suggestive of mechanical obstruction--although no clinical evidence of ductal obstruction was found. Necroinflammatory changes included spotty necrosis suggesting hepatitis of diverse etiologies (including viral infection and drug reaction) and chronic portal inflammation suggestive of chronic active hepatitis. Vascular changes consisted of sinusoidal dilatation (14 cases) and nodular regenerative hyperplasia (9 cases). In 6% of the patients, the only changes in the biopsy were those of granulomatous inflammation; each of these patients had a dominant mass ("sarcoidoma"), which had been biopsied to rule out tumor. Fibrosis was seen in 21% of the biopsies--periportal (13%), bridging (2%), or cirrhosis (6%). It is clear that sarcoidosis can cause progressive liver disease with a wide array of histologic features that can mimic those of other primary liver diseases.

Small cell osteosarcoma of bone: an immunohistochemical study with differential diagnostic considerations

Seventy-nine cases of small round cell tumors involving bone were studied in an attempt to learn whether the immunohistochemical features of the lesions might allow distinction of small cell osteosarcoma from other potential differential diagnostic considerations, including Ewing's sarcoma, atypical Ewing's sarcoma, primitive neuroectodermal tumor, mesenchymal chondrosarcoma, lymphoma, and the Askin tumor. The tissues studied were all formalin-fixed, decalcified, paraffin sections from patients between the ages of 16 and 48 years. With one exception (a small cell osteosarcoma), none of the lesions was cytokeratin positive. Moreover, none of the lesions was epithelial membrane antigen, desmin, factor VIII-related antigen, synaptophysin, or Leu-M1 positive. Accordingly, strong positivity for these antibodies in a majority of tumor cells should prompt inclusion of tumor types other than those listed above in the differential diagnosis. Vimentin positivity was seen in a majority of the tumors studied irrespective of histologic type. Scattered tumor cells (< 25%) showed positivity with antibodies to muscle-specific actin and smooth muscle actin in several of the different tumor types studied. No lesions other than lymphoma were leukocyte-common antigen (LCA) positive; all but two lymphomas were LCA positive, while all but one lymphoma were L26 positive. One (lymphoblastic) lymphoma was LCA and L26 negative. S-100, neuron-specific enolase, and Leu-7 did not prove to be specific for "neural-associated" tumors, but rather appeared in some small cell osteosarcomas, Ewing's sarcomas, atypical Ewing's sarcomas, primitive neuroectodermal tumors, mesenchymal chondrosarcomas, lymphomas, and Askin tumors. Antibody to cell surface antigen HBA71 was positive in three Ewing's sarcomas (two typical and one atypical) and negative in small cell osteosarcoma (three cases), mesenchymal chondrosarcoma (two cases), and lymphoma (one case). While some guidance may be derived from analysis of immunohistochemical staining patterns in a given lesion, the results reported in the present study do not suggest that routine immunohistochemistry alone will permit distinction of these small cell tumors of bone from one another. The value of immunohistochemical studies appears to lie particularly in the use of antibodies to LCA and S-100 protein to distinguish lymphoma and mesenchymal chondrosarcoma, and perhaps antibody to HBA71 to distinguish neural family lesions (such as Ewing's sarcoma), from other small cell tumors, such as small cell osteosarcoma.

Proliferative and histologically malignant struma ovarii: a clinicopathologic study of 54 cases

We reviewed 54 cases of struma ovarii with histologic features diverging from the normal pattern of benign thyroid tissue. These 54 lesions were divided into proliferative struma (41 cases) and malignant struma (13 cases). The patients diagnosed with proliferative struma ovarii ranged in age from 18 to 84 years (average, 44 years). The most common clinical findings among the proliferative struma patients were a mass (58%) and acute abdominal pain (12%). Preoperative evidence of hyperthyroidism was noted in three of the patients with proliferative struma, whereas one additional patient presented with ascites and hydrothorax ("pseudo-Meigs' syndrome"). Proliferative struma differed from the usual struma ovarii in that they comprised areas of densely packed follicles or papillary formations that raised the possibility of malignancy. However, none of the lesions that we have designated as proliferative struma ovarii showed histologic evidence of overlapping "ground glass" nuclei, vascular space invasion, or mitotic activity that would have supported an unequivocal diagnosis of malignancy. None developed metastases or recurrent disease. The 14 malignant struma ovarii manifested the classical features of thyroid carcinoma (including the presence of overlapping "ground glass" nuclei lining papillary formations and vascular space invasion). Patients with malignant struma ovarii ranged in age from 30 to 77 years (average, 50 years). Their clinical presentations included a mass (78%) and acute abdominal pain (22%). One patient had clinical and laboratory evidence of hyperthyroidism. On follow-up, one patient had persistent disease with peritoneal involvement, but distant metastases did not develop in any of these patients. A diagnosis of malignant struma ovarii should be reserved for lesions that exhibit the full range of changes seen in thyroid carcinoma arising in the cervical thyroid. By requiring that these rigid criteria be adhered to, the diagnosis of malignant struma ovarii will probably become less frequent as the more commonly encountered proliferative struma ovarii are recognized.

Synovial hemangioma: a report of 20 cases with differential diagnostic considerations

True synovial-based hemangiomas are uncommon lesions and, as such, may enter the differential diagnosis of other lesions encountered more frequently in clinical practice, including pigmented villonodular synovitis and traumatic hemarthrosis. The consultation files of the Armed Forces Institute of Pathology were searched for benign vascular lesions diagnosed as synovial or bursal hemangiomas vascular lesions diagnosed as synovial or bursal hemangiomas submitted between the years 1960 and 1985; 20 cases of synovial hemangioma were identified. The patients ranged in age from 9 to 49 years at the time of presentation (average age, 25 years). Sixty-five percent of the patients were male; 35% were female. Presenting symptoms included pain and swelling (31%), pain alone (31%), and a painless mass (31%). Affected regions included the knee (60%), the elbow (30%), and the finger (10%). In 65% of cases the lesion was confined to the intra-articular synovium; in 30% of cases the hemangioma was located in a bursa adjacent to a joint. One case was located largely within the joint cavity but had an area of extension into the suprapatellar recess. The dominant histologic patterns included cavernous hemangioma (50%), lobular capillary hemangioma (25%), arteriovenous hemangioma (20%), and venous hemangioma (5%). One lesion (which had been incompletely excised) was removed in its entirety 3 months after the initial subtotal resection; otherwise, none of the patients studied developed recurrent disease. The clinical diagnosis of hemangioma was made in 22% of cases, while an initial pathologic diagnosis of hemangioma was reached in 67% of cases. Pathologic differential diagnostic considerations include nonspecific synovitis/bursitis, pigmented villonodular synovitis, nodular synovitis, and organizing hemorrhage. A relationship between synovial hemangioma and pigmented villonodular synovitis was not suggested by this analysis of our material.

Postinfantile giant-cell transformation in hepatitis

Giant-cell hepatitis is a frequent pattern of liver injury in the neonate, but it is rare after infancy. Such cases have been attributed to autoimmune disease, to non-A, non-B hepatitis and, most recently, to paramyxovirus infection. To better define the entity of postinfantile (syncytial) giant-cell hepatitis, we reviewed 24 biopsy specimens from 20 patients with this finding, either alone or in combination with other diagnoses. The number of multinucleated giant cells varied greatly from one specimen to another. Varying degrees of portal inflammation appeared in all but one of the patients, and all had hepatitislike acinar inflammation associated with hepatocellular injury. Fibrosis was a common finding, varying from mild periportal fibrosis to established cirrhosis (33%). The changes were interpreted as acute giant-cell hepatitis in 25%, as CAH in 42% and as active cirrhosis in the remainder. The patients ranged in age from 2 to 80 yr, with a mean of 35 yr and a male/female ratio of approximately 1:1. The signs and symptoms of liver disease were present for more than 1 mo in most patients. A positive antinuclear antibody titer was found in seven of the patients. Three patients had a direct Coombs reaction and anemia. Overall, evidence of autoimmune disease was found in 40% of the patients. One patient had non-Hodgkin's lymphoma involving the liver. Only one patient had a history of blood transfusion or risk factors for hepatitis C. No patient underwent serological study for paramyxovirus antibodies. Liver tissue from one patient was examined ultrastructurally, but no viral particles could be identified.(ABSTRACT TRUNCATED AT 250 WORDS)

Extensive dermal metastases from primary signet-ring carcinoma of the urinary bladder

Dermal metastasis from internal carcinoma occurs infrequently. Bladder carcinoma is a rare source of skin metastasis. This report details the case of a twenty-five-year-old man with a fatal primary signet-ring adenocarcinoma of the bladder who experienced unique, extensive, infiltrative, cutaneous metastases within a few weeks of his initial presentation with an occultly carcinomatous ruptured spleen. The literature on cutaneous metastasis from carcinoma of the bladder is reviewed.

Cortical osteofibrous dysplasia of long bone and its relationship to adamantinoma. A clinicopathologic study of 30 cases

Thirty cases of cortical osteofibrous dysplasia (COFD) were studied in an attempt at defining the relationship of COFD to adamantinoma. The patients ranged in age from newborn to 39 years (mean 13.4 years). The male:female ratio was 1:1. Presenting symptoms were most often pain or a mass. The tibia was involved in all 30 patients; in addition, the ipsilateral fibula was involved in five patients (17%). The histologic appearance of the lesions was dominated by the combination of woven bone trabeculae with prominent osteoblastic rimming and a loose, slightly myxoid stroma (less heavily collagenized in most instances than usually encountered in intramedullary fibrous dysplasia). Results of immunohistochemical study showed isolated cytokeratin-positive cells in the stroma of 28 of the lesions (93%). However, hyperchromatic epithelial islands characteristic of adamantinoma were not found in any of the 30 cases. A control population of 50 fibro-osseous lesions (intramedullary fibrous dysplasia, sclerosing fibroxanthoma, and cranial ossifying fibroma) was studied immunohistochemically; in none of these control cases were cytokeratin-positive cells found. Follow-up data were obtained in 17 cases (57%); the period ranged from 1 to 16 years (mean 6.05 years). Certain overlapping clinical features (including the location of the vast majority of the lesions in the tibia and, less often, the fibula) and the morphologic similarities of many areas of COFD and adamantinoma (particularly the shared presence of cytokeratin-positive cells) suggest a more than coincidental association between COFD and a adamantinoma. However, to date none of the 30 cases of COFD evaluated in this study has developed an adamantinoma.

Fine-needle aspiration cytology of multicystic mesothelioma

This report details the cytologic findings from a case of peritoneal multicystic mesothelioma (MCM). Fine-needle aspiration of a 20 cm abdominal mass in a 31-year-old man yielded a specimen which consisted of a monomorphous population of mesothelial cells lacking cytologic atypia which were arranged in three patterns: monolayered sheets, single cells, and two-cell-thick strands of mesothelial cells with little or no intervening stroma. The background was clean, without necrotic debris or abundant inflammatory cells. The mesothelial cells were not arranged in prominent papillary formations; mitotic figures were not found. The mesothelial cells were cytokeratin positive and vimentin positive, and negative for carcinoembryonic antigen (CEA) and factor VIII. The FNA findings from MCM should be distinguished from those of a variety of other abdominal lesions, including cystic lymphangioma, ovarian and primary peritoneal epithelial tumors, necrotic tumors with cystic degeneration, developmental cysts, and infectious cysts.

Pediatric renal artery dysplasia: a morphologic study

Renal arteries from 12 pediatric patients who had stenosis due to renal artery dysplasia (9 surgical resections and 3 autopsy cases) were examined by light microscopy. The patients ranged in age from 15 months to 14 years; the male/female ratio was one. Bilateral renal artery disease was clinically diagnosed in 8 of the 12 patients; 6 of the 8 also had aortic anomalies. All of the lesions were designated as forms of dysplasia, a departure from previous reports in which dysplasia was subclassified as fibroplasia and hyperplasia. The most common lesion was medial fibrous dysplasia (6), followed by perimedial elastic dysplasia (4); intimal fibrous dysplasia (1) and medial muscular dysplasia (1) were the least common. Medial fibrous dysplasia was present as often with bilateral as with unilateral renal artery stenosis, while perimedial elastic dysplasia was seen exclusively in patients with bilateral renal artery disease. Three patients who came to autopsy had extrarenal vascular involvement by a similar dysplastic lesion. The three patients who had neurofibromatosis showed no distinctive histologic type of renal artery dysplasia.

The surgical pathology of gastrointestinal Hodgkin's disease

The files of the National Cancer Institute were searched for all surgical specimens from the gastrointestinal (GI) tract with the diagnosis of Hodgkin's disease (HD) that were accessioned during the years 1953-1990; six patients with a histologically reconfirmed diagnosis were identified. Of these patients, four presented with GI HD and two had recurrent HD. Primary HD appeared in the stomach (three patients) and the duodenum (one patient); recurrent HD after diagnosis in a conventional nodal site appeared in the stomach (one patient) and the colon (one patient). One of the cases of primary gastric disease was a composite lymphoma consisting of HD and diffuse large cell lymphoma. In view of the rarity of GI tract involvement by HD, a diagnosis of primary GI HD should be viewed with skepticism; support for such a diagnosis may be provided by both classic histopathologic features of HD and immunostaining, but no single feature can be regarded as pathognomonic.

Immunohistochemistry as a diagnostic aid in the interpretation of unusual mesenchymal tumors of the uterus

Sixty-three pure mesenchymal tumors of the uterus were studied to explore the value of immunostaining in the diagnosis of unusual mesenchymal tumors encountered in the uterus, some not reported previously. Each tumor was evaluated using a panel of immunostains including actin, desmin, vimentin, S-100 protein, and cytokeratin. The final classification, which incorporated the immunohistochemical findings, resulted in the identification of 33 relatively common pure mesenchymal tumors (13 benign and malignant endometrial stromal tumors and 20 benign and malignant smooth muscle tumors) and 30 uncommon tumors (five leiomyosarcomas with osteoclastic giant cells, two xanthomatous leiomyosarcomas, one melanotic schwannoma, one pure rhabdomyosarcoma, one neurofibroma, five plexiform tumorlets, and 15 combined smooth muscle-stromal tumors). The normal endometrial stroma, present in 14 cases, invariably showed a negative reaction for all antibodies. With rare exceptions, the pure endometrial stromal tumors displayed a negative immunoreaction for all antibodies utilized, while the pure smooth muscle tumors consistently showed a positive reaction for actin. Only the two tumors of neural origin (a neurofibroma and a melanotic schwannoma) reacted with S-100 protein. Immunostaining influenced most the final classification of neoplasms initially interpreted as uterine tumors with a sex-cord stromal pattern, endometrial stromal tumors that diverged from the classic lesions by having a spindle cell component, and intravascular leiomyomas with areas of compact proliferation of small round cells with prominent vascularity. All tumors in these three groups were reclassified as combined smooth muscle-stromal tumors following immunohistochemical studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Nonamyloidotic fibrillary glomerulopathy, immunotactoid glomerulopathy, and the differential diagnosis of filamentous glomerulopathies

Kidney biopsies from 12 patients between the ages of 10 and 63 yr were diagnosed as nonamyloidotic fibrillary glomerulopathy (NAFG) or immunotactoid glomerulopathy (IG) on the basis of the electron microscopic finding of filamentous or tubular material within the glomerular capillaries and mesangium. Six patients were male and six were female. Eleven presented with nephrotic syndrome and one with acute renal failure. Eight were hypertensive, and four of these patients had gross or microscopic hematuria as well. Biopsies from 11 patients were Congo red negative; one was weakly positive. By light microscopy, the predominant glomerular change was thickening of the capillary basement membrane with or without widening of the mesangium; these changes were suggestive of membranous glomerulonephritis. Immunofluorescent studies performed in four of the cases were positive for immunoglobulin G (IgG). Immunoperoxidase staining for beta 2-microglobulin was negative in four patients. Ultrastructurally, filaments or tubules were identified in the glomerular capillary basement membrane and/or mesangium in each patient. The filaments in NAFG, IG, amyloidosis, and other paraprotein deposits can be differentiated by size, arrangement, and location of filamentous material.

Myospherulosis of the mastoid antrum: a case report

Myospherulosis is a recently discovered iatrogenic disease caused by the implantation during surgery of mineral oil- or petrolatum-based products into various tissues. The condition results from the action of lipid substances on extravasated erythrocytes. The case report presented is the first detailed description of this uncommon, unique inflammatory lesion occurring in the mastoid and is the second otitic case reported in the literature. The lesion mimicked recurrent cholesteatoma 6 years following an intact canal wall mastoidectomy. As in myospherulosis of the paranasal sinuses, the symptoms and findings of otitic myospherulosis are those of the preceding disease.

Sequestration hypothesis of atherosclerosis

Atherosclerosis of the human aorta has been studied by morphometric, chemical, and histochemical methods. Results of these separate approaches are converging upon a theory of pathogenesis. This theory begins with the standard view of a two stage process, intimal fibroplasia followed by atheronecrosis in the most thickened and aged places. The first stage, fibroplasia, can be described in terms of a stochastic process wherein smooth muscle cells, scattered in accordance with a Poison distribution, elaborate matrix materials over time, causing the realms of the cells to expand and to aggregate. The fusion of the expanded smooth muscle cell realms seems to mark the advent of necrosis. The second stage, atheronecrosis, can be described such that the probability of a necrotic core emerging at a site in a vessel is governed by the amount and the age of interstitial matrix materials at the site. Further evidence shows that the matrix materials tend to sequester lipids in greater than proportionate amounts as the intimal bulk increases. The sequestered perifibrous lipid is histochemically different from the lipids of the necrotic core, in that only the latter can be fixed with chromic acid. These results suggest that lipids undergo a qualitative change as well as a quantitative increase at the stage of impending necrosis. This qualitative change is governed by age, which raises the possibility that necrotizing toxicity accumulates in the sequestered lipid as it ages.

Characteristics of the plaque under a coronary thrombus

Young men dying suddenly and autopsied by the coroner sometimes have coronary thrombosis at a relatively early stage of arteriosclerosis. The plaques under such thrombi often have a complex of features, a) rupture, b) hemorrhage, c) medial destruction, d) nodular collections of foam cells, e) calcification, f) cellular infiltrates of the fibrous cap, fibrous base and adventitia, and g) a newly described kind of phagocytic activity at the boundary between the necrotic core and the fibrous base of the plaque. Commonplace innocuous plaques in most middle and old aged subjects without heart disease also often have some of these features. What structural characteristics might distinguish rare thrombogenic from commonplace innocuous plaques? Twenty-one thrombotic plaques from 18 cases of sudden coronary heart disease (CHD) death were histologically compared with 129 nonthrombotic plaques from these same 18 cases, 85 plaques from 23 cases of CHD death due to arteriosclerotic occlusion, and 94 plaques from 22 cases having no CHD. Plaques with thrombosis all had necrotic cores; plaques for comparison with these were therefore chosen all to have necrotic cores. Rupture and hemorrhage were found in 90% of thrombotic plaques, with mixing of plaque gruel and blood in the thrombus. Medial destruction, foam cells and calcification (features c, d, and e) were commonplace in all types of plaques. Small-cell infiltrates and atherophagocytosis (features f or g) were found in 72-94% of the 21 thrombotic plaques, but only in 18-24% of the 94 not CHD plaques. The necrotic core, characterized by crystalline cholesterol, appears to incite cellular responses in some plaques but not others; those responses distinguish thrombogenesis. The findings imply that thrombogenicity and its accompanying plaque cellularity are incited not by cholesterol, but by some trace or minor component of the plaque gruel of the necrotic core. The possibility of testing these hypotheses by practical methods has been shown to be feasible.

Fibrous intimal thickening and atheronecrosis of the thoracic aorta in coronary heart disease

A series of 60 cases of coronary heart disease (CHD) deaths and 85 cases of Not-CHD deaths of a comparable age, race, and sex composition was assembled from a medicolegal service. Lateral walls of the thoracic aorta were sectioned, and measurements were made at 20 equally spaced points along the left and right sections, 40 points per case. At points having foci of atheronecrosis, the thickness of the necrotic focus and the fibroproliferative base and cap were measured. In points lacking atheronecrosis, full intimal thickness was measured. The sum of cap plus base is the total fibroproliferative tissue accompanying atheronecrosis. Aortas of CHD-death subjects had more necrotic points and more connective tissue associated with the necrosis. Aortas of CHD-death subjects also had proportionately less connective tissue in the cap rather than the base of necrotic lesions. These three variables contributed independently in a discriminant function, indicating that CHD-death status could in this set of cases best be predicted from the aortic condition by simultaneously considering the number of atheronecrotic foci, the bulk of connective tissue associated with those foci, and the relative thinness of the cap over the necrosis. One possible theory to explain these and other findings describes atherogenesis as the following two-phase process. In phase one, varying amounts of progressively increasing fibrous intimal thickening (preatheroma) are laid down. In phase two some loci develop atheronecrosis, a second set of loci develops accelerated fibroplasia, and a third set develops both features. The two features are each postulated to be increasingly likely to appear as intimal connective tissue increases. In this context the emergence of atheronecrosis, of accelerated fibroplasia, and of both together would be seen as greater in aortas of CHD-death subjects than in aortas of Not-CHD-death subjects.