255 A Rare Case of Combined Benign Adenomatoid Tumor and Myelolipoma of the Adrenal Gland

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Introduction/Objective Adenomatoid tumor is a rare benign nonfunctioning tumor of the adrenal gland of mesothelial cell origin. Myelolipoma, although rare, is the second most common benign tumor of the adrenal gland. Methods/Case Report A 59-year-old male, presented with renal mass noted on ultrasound during the work up of elevated creatinine. MRI revealed an exophytic cystic lesion arising from the superior pole of the left kidney, worrisome for renal cell carcinoma. Therefore, partial nephrectomy and adrenalectomy were performed. Grossly, a 4.2 cm tan-white multiloculated cystic mass was seen involving the adrenal gland, adherent to but without involving the kidney. Histologically, the adrenal gland was involved by two intermixed benign neoplasms. One exhibited microcysts, anastomosing tubules and gland like spaces lined by flat, cuboidal, and epithelioid cells without nuclear atypia or mitotic activity, morphologically consistent with adenomatoid tumor, and supported by positive immunostaining for AE1/AE3, D2-40, CK7, CK5, WT-1 and negative for HMB-45. In addition, intermixed parts of the tumor exhibited adipose tissue containing areas of trilineage hematopoiesis and osseous metaplasia, consistent with myelolipoma. Results NA Conclusion To our knowledge, ours is the 42nd case of adenomatoid tumor of the adrenal gland reported, and 3rd as combined and intermixed with myelolipoma, an exceptionally rare finding.