Hiroshi Iwasaki

Synovial sarcoma of the prostate with t(X;18)(p11.2;q11.2).

A case of monophasic synovial sarcoma of the prostate in a 37-year-old man is reported. Histologically, the tumor was chiefly composed of uniform spindle and oval cells, which often formed interlacing fascicles resembling those of fibrosarcoma. In some areas, the compact fascicles of tumor cells alternated with hypocellular myxoid tissue bearing a superficial resemblance to peripheral nerve sheath tumors, whereas small portions of the tumor showed a pericytomatous pattern consisting of polygonal cells arranged around dilated, thin-walled blood vessels. By immunohistochemistry, vimentin was detected in most cells, and a focal reactivity for epithelial membrane antigen was also observed. The tumor cells, however, were negative for keratin, S-100 protein, neuron-specific enolase, CD34, desmin, muscle-specific actin, and alpha-smooth muscle actin. Cytogenetic analysis and fluorescence in situ hybridization (FISH) using the cultured tumor cells demonstrated a translocation t(X;18)(p11.2;q11.2), an aberration specific for synovial sarcoma. To the authors knowledge, this is the first report of a primary prostatic synovial sarcoma confirmed by cytogenetic analysis.

Gastric carcinosarcoma (sarcomatoid carcinoma) with rhabdomyoblastic and osteoblastic differentiation

A rare case of carclnosarcoma (sarcomatoid carcinoma) with rhabdomyoblastic and osteoblastic differentlatlon occurrlng in the gastric remnant is reported. A 69‐year‐old Japanese man who had undergone a partial gastrectomy for a duodenal ulcer 30 years earlier, presented with anemla, eplgastralgia, and an abdominal mass. The diagnosls of gastric carcinosarcoma was made based on the findings of endoscoplc biopsies. The patient was thus scheduled to undergo a surgical operatlon, but he died of respiratory failure. At autopsy, a huge polypoid tumor measurlng 2Ox18times8 cm was located on the greater curvature of the gastric remnant. Microscopically, the tumor conslsted of Intimately mixed tubular adenocarcinoma and heterologous mesenchymal elements contalning rhabdomyosarcoma and osteosarcoma. Between these components, a morphological transition from the adenocarclnoma element to the sarcomatous element was observed. Ultrastructually, rhabdomyoblastlc dlfferentlation was conflrmed In the sarcomatous areas. lmmunocytochemlcal expresslons of epithelial markers includlng epithelial membrane antlgen and cytokeratlns (35bHll and 34bE12) were recognlzed not only in the carclnomatous cells but also In the sarcomatous cells. These findlngs suggest that carclnomatous cells appear to transform Into cells wlth sarcomatous features.

Angiogenesis in carcinosarcomas of the uterus : Differences in the microvessel density and expression of vascular endothelial growth factor between the epithelial and mesenchymal elements

Carcinosarcoma of the uterus is a highly aggressive neoplasm. However, the angiogenesis of this neoplasm is still unknown. This is the first study to examine the differences in angiogenesis between the epithelial and mesenchymal elements of this biphasic neoplasm. Surgical specimens from 21 primary uterine carcinosarcomas were histopathologically evaluated, and then immunohistochemically analyzed for tumor angiogenesis, using an anti-vascular endothelial growth factor (VEGF) antibody. The microvessel density (MVD) was also measured in each element of these neoplasms, using anti-CD34 monoclonal antibody. The MVD in the epithelial element was found to be higher than that of the mesenchymal element in 20 of 21 (95.2%) primary tumors. The epithelial elements showed a higher MVD (mean, 81.6 +/- 41.1) than the mesenchymal elements (mean, 36.7 +/- 23.8) in these primary tumors (P < .0001). Moreover, the epithelial elements showed a higher VEGF expression (mean, 0.78 +/- 0.23) than the mesenchymal elements (mean, 0.37 +/- 0.20) (P < .0001). The tumors with lymph-vascular invasion showed a higher VEGF expression (n = 17; mean, 0.85 +/- 0.17) than the tumors without lymph-vascular invasion (n = 4, mean, 0.47 +/- 0.12) (P < .01). Microscopically, neither lymph-vascular space invasion nor metastatic tumors consisted of sarcoma alone in this series. In addition, a decrease in the VEGF expression was found in the transitional areas between carcinomatous and sarcomatous elements in all 10 homologous and 4 heterologous tumors evaluated. These results suggest that the tumor angiogenesis in the epithelial element may be more active than that of the mesenchymal element and also substantiated the high metastatic potential of the epithelial element in uterine carcinosarcoma. Based on these findings, carcinoma cells thus may play a key role in the angiogenesis of this biphasic neoplasm.

Epithelioid sarcoma with an 18q aberration.

Epithelioid sarcoma is a peculiar soft-tissue neoplasm of uncertain origin, which is characterized by an epithelioid morphology of tumor cells coexpressing epithelial (keratin) and nonepithelial (vimentin) antigens. We herein report a new cytogenetic abnormality with der(22)t(18;22)(q11;p11.2) in a case of epithelioid sarcoma that occurred in the elbow of a 75-year-old man. Histologically, the tumor demonstrated a multinodular proliferation of epithelioid cells, with positive immunostaining for keratin, epithelial membrane antigen (EMA), and vimentin. Cultured tumor cells obtained from fresh surgical materials were frozen in plastic ampules and stocked in a liquid nitrogen freezer. Six years after surgery, the cells were recovered from the freezer and utilized for both morphologic and cytogenetic analyses. These cultured cells both before and after the freezing exhibited essentially the same epithelioid morphology and immunophenotypes as those of the original tumor. A chromosome analysis, together with fluorescence in situ hybridization (FISH), demonstrated a 61-67 modal population, and a characteristic clonal abnormality with der(22)t(18;22)(q11;p11.2). Other clonal abnormalities included numerical (-3, -4, +7, -13, -14, -16, -18, +20, -22) and structural (8p+, 9p+, 12p+, i(21q)) aberrations. Some variant clones also demonstrated i(18q). Since the breakpoint at 18q11 is similar to that reported in synovial sarcoma, this finding may support the presence of a histogenetic relationship between epithelioid sarcoma and synovial sarcoma. Our study thus indicates that the storage of frozen cells is useful for both morphologic and cytogenetic analyses of soft tissue tumors.

Renal Primitive Neuroectodermal Tumor: A Morphologic, Cytogenetic, and Molecular Analysis with the Establishment of Two Cultured Cell Lines

We report two patients with renal primitive neuroectodermal tumor (PNET) in whom the diagnosis was established by both a cytogenetic and a molecular analysis. Histologically, both renal tumors were composed of uniform immature round cells with a positive immunoreactivity for 013 (p30/32 MIC2). The cytogenetic analysis with in situ hybridization (chromosome painting) demonstrated reciprocal translocation t(11;22)(q24;q12) specific to PNET in the cultured cells derived from each tumor. The reverse transcriptase-polymerase chain reaction (RT-PCR) in both tumors demonstrated EWS/ FLI-1 fusion transcripts, representing the molecular equivalent of t(11; 22). A Southern blot analysis also confirmed EWS gene rearrangement in both renal tumors. In addition, the authors also established two new cell lines (designated as FU-RPNT-1 and FU-RPNT-2) from renal PNETs. When transplanted into athymic mice, FU-RPNT-1 and FU-RPNT-2 reproduced and maintained the morphologic and molecular characteristics of the original tumors. In conclusion, the detection of t(11; 22) and EWS/FLI-1 fusion transcripts is considered to provide a novel adjunctive method for diagnosing renal PNET. These newly established cell lines thus may be used to investigate the biologic behavior related to renal PNETs.

Renal primitive neuroectodermal tumor: An immunohistochemical and cytogenetic analysis

The cytogenetic and morphologic characteristics of a case with a primitive neuroectodermal tumor (PNET) arising from the left kidney in a 22 year old man are presented. The patient was detected as having a left renal mass with a tumor embolus In the inferior vena cava and multiple pulmonary metastases. A radical nephrectomy with tumor embolectomy of the Inferior vena cava, along with a resection of the pulmonary nodules were performed. Histologic examination revealed a dense proliferation of small round cells with many Homer‐Wright type rosettes and perlvascular pseudo‐rosettes. Immunohlstochemically, the tumor cells stained strongly positive for HBA71(p30/32M IC2), a surface glycopro‐teln specific to PNET and Ewlngs sarcoma. In addition, the tumor cells expressed several neural markers (neuron specific enolase, neurofilament, synaptophysin, and Leu‐7) and vimentin, while the epithelial, muscular, and lymphocytlc markers were negative in the tumor cells. Cytogenetic analysis of cultured tumor cells showed a reciprocal translocation t(11; 22)(q24; q12) that is considered to be specific to PNET and Ewings sarcoma. In conclusion, this case suggested that a karyotyping analysis is a useful diagnostic tool for renal PNET, and it may therefore be utilized to help distinguish between difficult cases of small round cell tumors and Wilms tumor of the kidney.

Intramuscular spindle cell hemangioendothelioma

Abstractu2002Spindle cell hemangioendothelioma occurring in skeletal muscle is extremely rare. No reported studies have performed an imaging evaluation of intramuscular spindle cell hemangioendothelioma. We report on such a tumor arising in an unusual site, the right extensor digiti minimi, in a 46-year-old woman. An en bloc resection was performed and the patient has been disease free for 8 years. Radiologic imaging in the present case showed similar findings to those described in intramuscular hemangioma.

Establishment and Characterization of a Serous Papillary Adenocarcinoma Cell Line of the Human Ovary in a Serum-free Culture

In order to clarify the biologic characteristics of serous papillary adenocarcinoma of the human ovary, we tried to establish a continuous cell line using four primary tumor specimens derived from four patients with such tumors. We also evaluated c-myc, MYCN and c-erbB2 gene amplification in the cultured cells, and the xenografts, as well as in these four primary tissue specimens by a Southern blot analysis. One continuous cell line, named as FU-OV-1, was established in a serum-free culture system and this line propagated continuously for 96 serial passages over a 2-year-period in vitro. FU-OV-1 reproduced and still maintained the characteristics of the original tumor. C-myc gene amplification was found in the FU-OV-1 cells, and the xenografts, as well as in only the primary tumor of FU-OV-1 out of the four primary serous papillary adenocarcinomas. However, neither MYCN amplification nor c-erbB2 amplification was observed in any tumor specimens including FU-OV-1 cells. In conclusion, FU-OV-1 is thus considered to be a useful system for studying the biological behavior of serous papillary adenocarcinoma in the human ovary. The results of this study suggest that c-myc gene amplification might thus be associated with the progression of this tumor both in vitro and in vivo.

Spindle cell carcinoma of the breast: A case report and an immunohistochemical study including p53 and Ki‐67 expression

A rare case of spindle cell carcinoma (SpCC) of the breast occurring In a 51‐yearold Japanese woman Is reported. A firm and well‐circumscribed tumor, measuring 9times8.5times8.5 cm, was located on the upper lateral region of the right breast. Microscopically, the tumor consisted of sheets of both malignant spindle cells and poorly differentiated ductal carcinoma containing squamold islands with gradual transition to the spindle cell component. The Immunocyto chemical expression of epithelial markers was recognized in the spindle cells, as well as in the carcinomatous cells. Moreover, the spindle cell component expressed vimentin, α‐smooth muscle actln and S‐100 protein. Ultrastructurally, in addition to the features of adenocarcinoma, squamous or rnyoeptthelial differentiation was confirmed in the spindle cell component. These findings thus suggest an epithelial origin with squamous differentiations and myoepithellal participation In the genesis of SpCC. In a comparative study, the expression of p53 protein and KI‐67 as a proliferation marker In each component of this tumor was also Investigated. The mean p53 labeling index (LI) in both the carcinomatous and spindle cell area was similar, however the mean MIB‐1 LI in the spindle cell area was significantly higher than that in the carcinomatous area. The results indicate that p53 over‐expression is Involved In the tumorigenesis of both components in the SpCC, and the spindle cell component shows a higher degree of proliferative activity than the carcinomatous component.

Giant cell tumors of tendon sheath: A single and multiple immunostaining analysis

Nineteen giant cell tumors of tendon sheath (GCTTS) were studied to elucidate the origin of the proliferating cells of these tumors, using single and multiple immunostaining techniques with a labeled avidin‐biotin [LAB] method in paraffin‐embedded tissues. Proliferating cell nuclear antigen (PCNA) and Ki‐67 (MIB‐1) antigen were present in mono‐nuclear cells (PCNA 26%; MIB‐1 4%) but were absent in giant cells. These findings indicate that mononuclear cells, but not giant cells, participate in the proliferative compartment of GClTS. A histiocytic marker, HAM56, was positive in many mononuclear cells (mean 81%), but was totally negative in osteoclastic giant cells. Another histiocytic antigen, CD68, was expressed in both mononuclear cells (mean 28%) and most of the giant cells (mean 89%). By triple immunostaining for PCNA, HAM56 and vimentin, 83% of PCNA‐positive mononuclear cells co‐expressed HAM56. Because of the frequent co‐expression of PCNA and HAM56, the main portion of proliferating cells in GClTS may represent a mono‐cyte/macrophage lineage. However, there is a small but definite mesenchymal/fibroblastic component, characterized by PCNA+vimentin+HAM56‐‐, relating to the proliferative compartment of GCTTS. Multiple immunostainings with MIB‐1 showed similar patterns to those with PCNA. These observations indicate that the GCTTS represent bimodal proliferatbe lesions consisting of histiocytic and mesenchymal/fibroblastic elements.