[Cytology positive for malignant cells in hydrocele secondary to testicular seminoma]

Finding tumor cells in the fluid of hydrocele secondary to testicular tumor is rare and may be due to the fact that hydrocele fluid cytology has not been studied systematically. The presence of malignant cells in the hydrocele fluid may be ascribed to two mechanisms: retrograde lymphatic flow from the infiltrated retroperitoneal lymph nodes or from tumor directly invading the tunica albuginea and vaginalis testis, with cells passing into the cavity of the vaginalis. Only two cases of hydrocele secondary to testicular seminoma with vaginalis fluid cytology positive for malignant seminomatous cells have been previously reported in the literature. To our knowledge, the case reported herein is the third. These three cases are briefly discussed.