Primary retroperitoneal seminoma diagnosed by fine needle aspiration biopsy. A case report.

A fine needle aspiration biopsy specimen of a retroperitoneal mass was submitted for cytologic evaluation. Malignant cells were found, and the cytologic appearance was consistent with seminoma although the clinical possibilities included lymphoma and adenocarcinoma of the pancreas. Cytologic features of the needle biopsy specimen included uniform neoplastic malignant cells with round nuclei and nucleoli and clear or pale-staining cytoplasm. The cells were found singly or in groups of two or three cells. Lymphocytes were intermingled with the neoplastic cells.