Diagnostic limitations in testicular cytopathology: to what extent is fine-needle aspiration reliable for the diagnosis of epidermoid cyst of the testis?

This article describes the cytologic and histologic findings of a epidermoid cyst of the testis diagnosed by means of fine-needle aspiration (FNA) cytology. The gross and cytologic features are creamy aspirate, squamous cells, squamae, and fragments of granulomatous tissue. The cytologic features are fairly typical and similar to those observed in cutaneous epidermoid cysts; however, in this setting, the differential diagnosis should be carried out mainly with teratoma and dermoid cysts. The patient's age and precise location of the mass are paramount in the differential diagnosis. We believe that FNA is a reliable tool for the diagnosis of testicular epidermoid cysts, but the differential diagnosis with dermoid cysts should be based on histology.