Norio Shinohara

The role of MR imaging in the diagnosis of alveolar soft part sarcoma-a report of 10 cases

ObjectiveThe objective of this study was to analyze the characteristics of alveolar soft part sarcoma using magnetic resonance imaging (MRI).DesignMRI studies of pathologically proven alveolar soft part sarcomas (ASPS) in ten patients were reviewed and compared with computed tomographic (CT) studies and angiograms.PatientsTen patients presented with a soft tissue mass of the extremities, neck, axilla, or buttocks. MR images were obtained in all patients prior to surgical intervention, chemotherapy, or irradiation.Results and ConclusionAlthough most soft tissue sarcomas are isointense relative to muscle on MRI T1-weighted images (T1WI), nine of the ten alveolar ASPS in the present study demonstrated high signal intensity on both T2 and T1WI. Flow voids were observed both at the core and at the margins of the tumors studied. Recognition of these characteristic MRI findings may lead to the early diagnosis of ASPS, especially when the clinical presentation is that of a slow-growing soft tissue mass in a young adult patient.

Intramuscular myxoma: a clinicopathologic, immunohistochemical, and electron microscopic study

This Clinicopathologic study concerns 17 cases of intramuscular myxoma, including an immunohistochemical survey of 10 cases and an electron microscopic examination of 4. There was a female preponderance in a ratio of 14:3. The most common sites of tumors were the large muscles of the thigh (seven cases), followed by those of the buttock (three) and the lower leg (three). The size of the tumor ranged from 1.5 to 20 cm (median, 6 cm) in the greatest diameter. Neither recurrence nor metastasis was seen in any of 15 patients for whom information was available. In addition to the conventional microscopic features, such as hypocellularity, absence of a plcxiform capilliary network, and no detection of typical glycogenrich lipoblasts, the following findings were regarded as helpful to differentiate an intramuscular myxoma from myxoid liposarcoma: (1) hypovascularity of the tumor, demonstrated by angiography; (2) a homogeneous computed tomography appearance with low density, (3) absence of S‐100 protein immunoreactive cells such as lipoblasts; and (4) electron microscopically, the constituent cells were predominantly fibroblastlike cells with a prominent secretory activity, together with a small number of primitive mesenchymal cells and histiocyte‐like cells, but with no lipoblasts. After simple excision, the 15 patients who could be followed are well with no recurrence during various periods of follow‐up.Cancer 58:740‐747, 1986.

EXTRASKELETAL MYXOID CHONDROSARCOMA: A Clinicopathologic and Electron Microscopic Study

This clinicopathologic study concerns 14 cases of extraskeletal myxoid chondrosarcoma from among 603 cases of soft tissue sarcomas. The ages of the patients at the time of initial biopsy ranged from 16 to 69 years. The tumors mainly arose in the lower extremities including buttocks (10 cases), and consisted histologically in cords and strands of small acidophilic cells with occasional vacuolated cells in an abundant myxoid matrix composed of chondroitin sulfate. Electron microscopy in four revealed a continuum of cell differentiation of the tumor cells from chondroblastic cell to undifferentiated mesenchymal cell. Morphological studies Indicated that the extraskeletal myxoid chondrosarcoma Included so‐called chordoid sarcoma, as a variant.

Infantile digital fibromatosis. Ultrastructural, histochemical, and tissue culture observations

Three cases of infantile digital fibromatosis were studied by electron microscopy, enzyme histochemistry, and tissue culture. The tumors were made up equally of myofibroblasts containing electron‐dense inclusions which were composed chiefly of microfilaments measuring about 5 to 7 nm. Dense bodies usually observable in the smooth muscle cells were found in the bundles of these microfilaments and in the processes of the inclusions, suggesting that these inclusions may represent an abnormal accumulation of contractile protein in the cytoplasm of tumor cells. Two cell lines were established from culture of the tumor cells, and the cultured cells also contained inclusion bodies showing the same morphologic characteristics as those of the original tumor cells. Lysosomal enzymes were abundant in the cultured cells, but they were scant in the cells of the fresh tissue specimens. Cocultivation of the cultured cells with human embryonic lung cells yielded no cytopathic effect.

Malignant fibrous histiocytoma. A tumor of facultative histiocytes showing mesenchymal differentiation in cultured cell lines.

The histogenesis of malignant fibrous histiocytoma (MFH) is controversial. To elucidate the cellular origin and characteristics of this neoplasm, the authors analyzed cell lines grown from 17 patients (15 soft tissue MFH and 2 bone MFH) by using light and electron microscopy, immunocytochemistry, enzyme cytochemistry, and functional tests for receptors for the Fc portion of immunoglobulin (Fc receptors) and immunophagocytosis. Each culture exhibited a storiform/pleomorphic pattern with mixed cellular populations consisting of spindle cells, polygonal cells, and bizarre giant cells; these morphologic features corresponded to the histologio characteristics of the primary tumors. The cells in each MFH line displayed histiocytic functional markers such as lysosomal enzymes, Fc receptors, and immunophagocytosis. However, these cells differed from monocyte‐derived macrophages (histiocytes) in immunoreactivity; the MFH cells expressed a mesenchymal antigen (FU3) distributed among perivascular cells and fibroblasts but demonstrated no positive reactions with Leu‐M1 (CD15) and Leu‐M3 (CD14), which recognize the cells of the monocyte‐macrophage lineage. In conclusion, these findings suggest that MFH is not a tumor of true histiocytes but of facultative histiocytes showing mesenchymal differentiation in vitro. Chromosomal analysis performed in one MFH line demonstrated abnormal karyotypes; the modal chromosome number was 58, with 5 marker chromosomes.

Malignant fibrous histiocytoma. Proliferative compartment and heterogeneity of "histiocytic" cells.

To elucidate the precise origin and characteristics of the proliferating cells in malignant fibrous histiocytoma (MFH), the authors analyzed 33 MFH tumors, using immunohistochemical techniques with a panel of 12 antibodies. All three types of MFH cells (spindle cells, polygonal cells, and bizarre giant cells) stained positively for mesenchymal antigens (FU3 and vimentin) but did not stain for macrophage/histiocyte markers (HAM 56 and CD68). Therefore, the MFH cells may not represent true histiocytes, although they may be mesenchymal-derived cells behaving as “facultative histiocytes” with superficial resemblance to actual histiocytes. Normal histiocytes in the stroma tested positive for macrophage/histiocyte antigens; the most common cells were HAM 56-positive cells constituting 30-80% of nonneoplastic stromal cells, followed by those positive for CD68 (10-50%), Mac 387 (<2%), and S-100 protein (<1%). Our results indicate the presence of heterogeneity of “histiocytic” cells in MFH. Proliferating-cell nuclear antigen (PCNA) was expressed not only in the spindle and polygonal MFH cells but also in the bizarre giant cells. These findings suggest that all three types of MFH cells participate in the proliferative compartment of MFH. Uneven PCNA staining of the irregular nuclear segments of the bizarre giant cells may result in abnormal DNA synthesis, possibly contributing to the marked diversity of nuclear morphology in MFH. Touton- type and osteoclast-like giant cells did not stain for PCNA but stained positively for histiocytic markers. Therefore, these giant cells may lack proliferative activity and probably result from normal histiocytes fusing together.

Chromosome abnormalities in liposarcomas

We performed a cytogenetic study of short-term cultures from fresh surgical specimens obtained from four patients with liposarcoma. Myxoid liposarcomas (cases 1-3) were associated with a specific translocation between chromosomes 12 and 16. Trisomy 8, a nonrandom secondary aberration in myxoid liposarcoma, was observed in the third case as the only additional change. Round cell liposarcoma (case 4) showed complex chromosomal aberrations affecting chromosomes 1, 2, 5, 6, 7, 13, 14, 17, 19, and 22. Neither band 12q13 nor 16p11 was visibly rearranged. Three subgroups of liposarcomas are proposed. The first group is characterized by t(12;16)(q13;p11), the second group by ring chromosomes, telomeric associations, and giant markers, and the last by complex numerical and structural aberrations.

Supernumerary ring chromosomes and nuclear blebs in some low-grade malignant soft tissue tumours: atypical lipomatous tumours and dermatofibrosarcoma protuberans

Abstract We investigated the diagnostic significance of supernumerary ring chromosomes in low-grade soft-tissue neoplasms. Chromosome slides were prepared from 123 samples of soft-tissue tumours using the standard trypsin-Giemsa banding technique. Supernumerary ring chromosomes were found in 6 cases of soft tissue tumours: 5 cases of atypical lipomatous tumour (ALT) and 1 case of dermatofibrosarcoma protuberans (DFSP). By chromosome painting with fluorescence in situ hybridization (FISH), the ring chromosome in 1 ALT was painted over its entire length with the chromosome 12 probe. Nuclear blebs and micronuclei, which were observed in each case of ALT, also contained chromosome 12 material; and these structures may represent a topological distribution of ring or giant marker chromosomes in the interphase nuclei. Our findings suggest that supernumerary ring chromosomes are characteristic of some low-grade soft tissue neoplasms including ALT and DFSP.

Epithelioid sarcoma. A clinicopathologic and electron microscopic study.

This clinicopathologic study concerns four cases of epithelioid sarcoma, which were seen among a group of 603 cases of soft tissue sarcomas in our file. The patients were of young age between 8 and 21 years at the time of initial treatment. The tumors arose in the upper (2 cases) or lower extremities (2 cases), and consisted histologically of irregular nodular masses of polygonal epithelioid cells merging with spindle cells. Electron microscopy in two cases revealed that the tumor cells were an admixture of synovioblast‐like cells and fibroblast‐like cells, the former cells being characterized by pseudoacini and filopodia. In three of the four patients, the tumors recurred one to three times, and one patient with primary tumor had metastases to the skin of the more proximal portions of the same extremity and to the regional lymph nodes. Follow‐up ranging from two to four years, however, revealed that all patients were living and well after single or multiple operations.

Osseous xanthomatosis and a pathologic fracture in a patient with hyperlipidemia: a case report

Osseous xanthomatosis and a pathologic fracture of the femoral neck associated with hyperlipoproteinemia occurred in a 48-year-old woman. Widely distributed skeletal lesions suggested a primary neoplasm such as malignant lymphoma or multiple myeloma; however, needle aspiration cytology of the fracture site, cutaneous manifestations, and abnormally high concentrations of lipoproteins established a diagnosis of intraosseous xanthomatosis associated with hyperlipidemia. Histologically, the excised femoral head showed a dense aggregate of lipid-laden macrophages and depletion of normal bone trabeculae. The hyperlipidemia is classified as Type IIb hyperlipoproteinemia.