Vascular adrenal pseudocyst: cytologic and immunohistochemical study.

Adrenal vascular cysts are rare lesions that might be considered in the differential diagnosis of adrenal tumors. Their origin is not clear. We report the clinicopathological findings of a large adrenal hemorrhagic pseudocyst (AHP) in a 73-yr-old man who complained of abdominal pain. An abdominal CT showed a 9 cm tumor in the left adrenal. A fine-needle aspiration biopsy (FNAB) was hemorrhagic and inconclusive. The tumor was excised and touch imprints were taken showing groups of spindled and fusiform cells with elongated nuclei, without atypia. Histologically, the tumor was well delimited by a fibrous capsule and contained numerous cystic spaces lined by endothelial cells and filled with erythrocytes, fibrin thrombus, and necrotic debris. Immunohistochemical study showed strong positivity for factor VIII-RA, CD31, and CD34. Also, the remaining adrenal showed a prominent frame of thin and medium caliber vessels, supporting a vascular origin for this entity. This case illustrates the difficulty in making a diagnosis by FNA and to keep in mind AHP when hematic aspirates are obtained from an adrenal tumor mass. Copyright 2000 Wiley-Liss, Inc.