Almost all solid scrotal masses are malignant tumors. Among these, tumors originating from mesothelium, are usually benign. Adenomatoid tumors constitute the majority of the solid tumors with mesothelial origin. Although adenomatoid tumor can be seen at all ages, it is mostly common in the third and fifth decades. These tumors, which are treated surgically, may pose some diagnostic difficulties.

Adenomatoid tumor occurs mostly in the lower pole of the epididymis and rarely in the tunica albuginea and spermatic cord. When localized at the tunica albuginea, it can be confused with sex cord tumors, benign mesenchymal tumors and malign mesothelioma. Vascular tumors mostly take place in the differential diagnosis of these tumors. Adenomatoid tumors, which are mainly composed of spindle and signet ring cells can simulate a metastatic tumor. Therefore the discrimination of adenomatoid tumor, which is known to originate from mesothelium, necessitates additional immunohistochemical studies, which will emphasis morphologic findings.