Cribriform and sclerosing seminoma devoid of lymphoid infiltrates.

The clinical, gross, microscopic, and ultrastructural features of a histologically atypical testicular seminoma were studied. Microscopically, the tumor consisted of uniform polygonal cells, with either clear or granular cytoplasm, arranged in a nested cribriform pattern. Nests of tumor cells were surrounded by broad bands of acellular fibrous tissue devoid of typical lymphoid infiltrates. Ultrastructurally, the tumor was indistinguishable from classic seminoma. Despite the large size of the tumor and the presence of abdominal metastases, the patient's condition responded favorably to chemotherapy and he is free of tumor four years after initial therapy.