Adrenal myelolipoma: fine-needle aspiration of an asymptomatic retroperitoneal mass.

We report a case of myelolipoma of the adrenal gland diagnosed by ultrasound-guided fine-needle aspiration in a patient with bronchogenic carcinoma who was noted to have a 5-cm adrenal mass on computerized tomography during evaluation for metastatic disease. The cytologic features are characteristic and consist of mature adipocytes and bone marrow elements that are most clearly demonstrated on Wright-stained cytospin material. This case illustrates the importance of fine-needle aspiration in the evaluation of radiologically detected adrenal masses in patients with known malignancies. A cytologic diagnosis of benign or metastatic disease can eliminate the need for formal surgical exploration in selected cases.