Adenomatoid Tumor of Tunica Albuginea Mimicking Seminoma on Fine Needle Aspiration Cytology: A Case Report

Adenomatoid tumor is one of the most common primary neoplasms of the paratesticular area. The epididymis is the most common site of involvement; however, it can also arise from the tunica albuginea, spermatic cord, tunica vaginalis and testis. Fine needle aspiration cytology (FNAC) is being increasingly used for lesions in the paratesticular area. Review of the literature showed very few reports on the cytologic features of adenomatoid tumor. We report the cytologic features of a case of adenomatoid tumor arising from testicular tunica albuginea. A 40-year-old man presented with right-sided scrotal swelling of 1 years' duration. FNAC of the lesion showed highly cellular smears composed of clusters of monomorphic plump cells with oval eccentric nucleus, fine granular chromatin, small single nucleolus and abundant pale to vacuolated cytoplasm. The background showed "tigroid substance," classically described in seminoma. Histopathologic examination confirmed the diagnosis as adenomatoid tumor of tunica albuginea. FNAC of an adenomatoid tumor poses a diagnostic challenge when the tumor arises from sites other than the epididymis because they can be mistaken for intratesticular tumors. It is thus important to consider this tumor in the differential diagnosis of scrotal swellings.