Serous psammocarcinoma of the ovary and peritoneum.

We report 11 cases of serous psammocarcinoma, a rare variant of serous carcinoma characterized by massive psammoma body formation and low-grade cytological features. The patients ranged in age from 36 to 76 (mean of 57) years. The tumors were stage three in every case (three stage IIIA, seven stage IIIB, and one stage IIIC). Eight of the patients had ovarian psammocarcinomas with ovarian tumors measuring 5-22 (mean of 11) cm in diameter; the other three patients had primary peritoneal psammocarcinomas. The surfaces of the ovarian tumors were smooth and intact in seven of eight ovarian psammocarcinomas. Cysts were present in six of eight ovarian tumors, and the solid portions were typically gritty or granular. Necrosis was not seen. Microscopically there was destructive invasion of ovarian stroma or vascular invasion in the ovarian tumors; the extraovarian tumor implants were invasive of intraperitoneal viscera in five cases. The epithelium was arranged in small nests with no areas of solid epithelial proliferation, and at least 75% of the epithelial nests were associated with psammoma body formation. No more than moderate nuclear atypicality was identified in any case. No mitotic figures were found in 10 of the tumors, with a single mitotic figure identified in the other tumor. Follow-up data for more than 1 year was available for six patients, with two patients lost to follow-up and three patients followed without evidence of recurrence for less than 1 year. One patient died of tumor 6 1/2 years after presentation, and five patients were alive without evidence of recurrent tumor 3-10 (mean of 8.3) years after presentation. Although based on a small number of cases, these data suggest that the clinical behavior of psammocarcinoma more closely resembles that of borderline serous tumors than of serous carcinomas of the usual type, following a protracted course and being associated with a relatively favorable prognosis.