Six patients with metastatic mixed germ‐cell tumors who had been treated successfully with chemotherapy had recurring solitary enlarging masses. Four had enlarging pulmonary masses and two patients had enlarging abdominal masses. Each had the presumed chemotherapy refractory mass surgically resected and was found to have mature teratoma with absence of malignant histologies. The growth in two patients can be attributed to tense and expansile cysts; the remaining four had firm masses. All patients remain free of disease without further therapy at 5, 13, 14, 25, 66, and 108 months. Early recognition of this previously unreported and unusual clinical circumstance of a benign teratoma to grow after chemotherapy will allow for surgical salvage.

Forty-two cases of sarcomatoid renal cell carcinoma were reviewed clinicopathologically. Twenty-four patients were men, and 18 women; average age was 56.2 years (range, 30-81 years). Eight, 9, 13, and 12 cases were Stages I, 11,111, and IV, respectively. Three morphologic patterns of sarcomatoid components were identified: malignant fibrous histiocytomatous (26 cases), fibrosarcomatous (6 cases), and unclassified sarcomatoid (10 cases). Mitotic count, degree of pleomorphism, cellularity, and amount of tumor matrix in the sarcomatoid areas, and similar morphologic parameters in the carcinomatous component all failed to correlate with prognosis, as did tumor size and renal vein involvement by tumor. Clinicopathologic stage was a most significant prognostic factor, with a survival of 49.7 months for Stage I and 6.8 months for combined Stages 11,111, and IV. Tumor necrosis in the sarcomatoid area and proportion of sarcomatoid components were also poor prognostic factors. When these factors were compared to the stage, necrosis was an independent variable, however, proportion of sarcomatoid components was a poor prognostic indicator only for Stages I and 11. Cancer 59516-526, 1987. ARCOMATOID RENAL CELL CARCINOMA is an un-S common, but not rare, neoplasm consisting of a typical renal cell carcinoma associated intimately with a sarcomatoid component.' It has been reported that sar-comatoid renal cell carcinoma constitutes approximately 1.0% to 1.5% of the total number of renal parenchymal tumors. ' 3 ' This tumor has received only scant and incidental a t t e n t i ~ n ~-~ ; only two relatively large series',2 have appeared in the literature. Although prognosis in sarcomatoid renal cell carcinoma is known to be extremely poor,'S2 little is known about what clinicopathologic information is prognostic. Furthermore , no studies have been done to correlate histologic features in this group of tumors with survival. Therefore, in an attempt to better understand this disease and to identify prognostic pathologic factors, we reviewed 42 cases of sarcomatoid renal cell carcinoma. Materials and Methods All kidney tumors diagnosed as sarcomatoid renal cell carcinoma, carcinosarcoma, adult Wilms' tumor, and sarcoma of the kidney from 1973 to 1983 at The University of Texas M. D. Anderson Hospital and Tumor Institute at Houston were analyzed. Cases were included in the study only if they contained recognizable renal cell carcinoma and a definite sarcomatoid component. All sarcomas not demonstrating epithelial elements were excluded. Neoplasms with embryonal stroma that contained glomeruloid structures and lacked areas of typical adult renal cell carcinoma (adult Wilms' tumor) were also excluded. Microscopic slides were reviewed without knowledge of the clinical information. The follow-up period was dated from the time of initial histologic diagnosis. The original slides were reviewed in all cases, and, when needed, the paraffin blocks were obtained and recut. The average number of slides per case was 10.5 (range, 5-25). The sarcoma...

No abstract