Histological typing and morphological characterization of canine seminomas

The aim of this study was to evaluate seminomas based on cell morphology and histological structures, and classify them into subtypes. Thirty canine seminomas were stained with hematoxylin-eosin (HE) and Periodic Acid Schiff (PAS). PAS-positive cases were classified as Classical seminoma (CS) (n:5), while PAS-negative cases were categorized as Spermatocytic seminoma (SS) (n:23). Cases exhibiting both positive and negative staining were evaluated as Spermatocytic/Classical seminoma (n:2). Carcinoma in situ were observed in the cases with Classical seminoma (n:3). The cell morphology included mitotic index were also given in detail. Canine seminomas were classified into three subtypes: intratubular (n:12), diffuse (n:1), and intratubular/diffuse (n:10). As a result, it was thought that SS and CS types could be observed together, and it was observed that the intratubular/diffuse subtype is a third type characterized by its transformation from intratubular to diffuse form.