Fine-needle aspiration biopsy of seminoma and dysgerminoma: cytologic, histologic, and electron microscopic...

Cytomorphologic features in a series of fine-needle aspiration biopsies from eight patients with seminoma or dysgerminoma were reviewed, and the findings were further correlated with histopathologic and ultrastructural appearances. Three cell types were encountered. Type I was least differentiated and least frequent. Type II was most frequent and had well-developed cytoplasm rich in organelles. Type III was similar to type II but also contained abundant cytoplasmic glycogen. In cytology smears, type III cells contained large punched-out cytoplasmic vacuoles corresponding to the areas of glycogen deposition. The background contained a variable mixture of inflammatory cells including lymphocytes, plasma cells, epithelioid cells, and epithelioid granulomas. The significance of these findings in the diagnosis of seminoma or dysgerminoma and the distinction from other germ-cell and non-germ-cell tumors is briefly discussed.