Adenomatoid tumor of the adrenal gland: case report with immunohistochemical study.

Adrenal adenomatoid tumor (AT) is a recently recognized disease with marked male predominance. Herein is presented a case of adrenal AT incidentally found in a 30-year-old man and results of immunohistochemical examination of the tumor. The left adrenal gland, weighing 17 g, contained a mass measuring 3 x 2.5 x 2.5 cm in the cortical tissue. Cut surface showed a relatively well-circumscribed firm tumor with a white solid appearance. Histologically, the tumor had the typical appearance of AT described in the genital tract. Immunohistochemically, the tumor cells were positive for calretinin, D2-40, WT1, mesothelial cell antigen, CA125, thrombomodulin, vimentin and cytokeratins (stained by AE1 + AE3, OV-TL 12/30, CAM5.2 and MNF116), and negative for endothelial markers (CD31, CD34 and factor VIII-related antigen) and CD56. CD56-positive adrenocortical cells were diffusely scattered in the tumor, especially in its periphery. Immunohistochemistry of estrogen, progesterone and androgen receptors was negative. These findings confirm mesothelial origin of the tumor and suggest that this tumor has little relation to sex hormone despite male predominance.