A previously healthy, 37-year-old man presented for a routine physical examination during which a pulsatile mass in his midepigastrium was palpated. Abdominal ultrasonography showed a well-defined hypoechoic lesion abutting the pancreas. Further imaging by contrast-enhanced computed tomography (CT) and 3-dimensional reconstruction revealed a well-circumscribed, 3-cm lesion surrounding the common hepatic artery (Figure, A and B). The lesion demonstrated patchy arterial enhancement, and a small irregularity of the common hepatic artery was present within the lesion. Endoscopic ultrasonography demonstrated a hypoechoic, well-defined mass; fine-needle aspiration showed no abnormal cells within the paucicellular specimen. Surgical exploration revealed a firm, ovoid lesion surrounding the hepatic artery at the origin of the gastroduodenal artery (Figure, C). Following resection, the lesion was bisected to reveal a smooth white arterial lumen surrounded by grayish fibrotic tissue with punctate hemorrhagic foci. Histologic sections of the specimen demonstrated small, singly dispersed vessels embedded in a background of fascicles of spindled cells with monotonous, fusiform nuclei and abundant eosinophilic cytoplasm. Focally, areas of myxoid degeneration were present. Despite extensive sampling, no mitotic activity, cytologic atypia, or areas of necrosis were identified. There was strong, diffuse cytoplasmic staining for desmin (Figure, D), and staining results for S100 were negative. Furthermore, CD34 stained strongly positive in vessels but failed to highlight the intervening stroma.
Krampitz GW, Mills AM, Visser BC. Man With Hypoechoic Lesion Abutting the Pancreas. JAMA Surg. 2014;149(4):393-394. doi:10.1001/jamasurg.2013.778