A 61-year-old white woman experienced progressive right flank pain over a 6-month period. Cross-sectional imaging (computed tomography [CT] of the abdomen and pelvis; MR venogram) demonstrated a 10.9 x 9 x 8.4 cm right adrenal mass with concern for liver invasion and inferior vena cava involvement. Her metastatic workup was negative. She underwent an adrenal metabolic workup that revealed normal plasma metanephrines. A CT-guided biopsy revealed a poorly differentiated primary small cell carcinoma of the adrenal gland.