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Abstract

Case presentation: A 23-year-old male presented with a 6-month history of uncontrolled hypertension on 3 agents, with unintentional weight gain. He reported generalized fatigue, lower extremity edema, easy bruising, nocturia, insomnia, and irritability. The patient had no known pertinent personal or family medical history. Physical examination revealed truncal obesity, moon facies, dorsocervical fat pad, and violaceous striae. His laboratory results were as follows: 1-mg overnight dexamethasone suppression test (cortisol, 32.7 μg/dL); 24-hour urine free cortisol (UFC) of 1,643 μg; midnight plasma cortisol of 38.68 μg/dL, late-night salivary cortisol of 1.016 μg/dL (reference, 0.010 to 0.090 μg/dL); adrenocorticotropic hormone (ACTH) of 290 pg/mL (reference, 7.2 to 63.3 pg/mL); hyperglycemia; hypokalemia; and 8-mg dexamethasone suppression test (cortisol, 37.56 μg/dL). Pituitary magnetic resonance imaging scan was normal. A chest computed tomography (CT) scan showed a 3 × 6 cm mass within the left lower lobe, with left hilar lymphadenopathy (Fig. 1). Positron emission tomography (PET) and Octreoscan testing revealed a hypermetabolic left lower lobe mass with concurrent hilar lymphadenopathy and normal physiologic fluorodeoxyglucose activity within the liver (Fig. 2A), with somatostatin receptor avidity (Fig. 2A). Bronchoscopy failed to reveal any intraluminal masses. The patient was referred for resection of the left lower mass by lobectomy and lymph node dissection. The pathology result showed polygonal cells with abundant cytoplasm, round nuclei, and punctate necrosis (Fig. 3). What is the diagnosis?