Pathology Quiz Case 2

Abstract

A 46-YEAR-OLD MAN PRESENTED WITH A several-month history of dysphagia. He was otherwise healthy, denied tobacco or alcohol use, and reported a history of tonsillectomy. His voice was clear. Flexible laryngoscopy demonstrated a polypoid mass that filled the right piriform sinus and spilled into the laryngeal introitus (Figure 1). The vocal folds were mobile. A contrast computed tomogram of the neck showed a cystic-solid lesion in the region of the right piriform sinus, with an associated mass effect. The patient elected to undergo transoral laser excision of the hypopharyngeal mass. The resection was performed with suspension laryngoscopy and a handheld carbon dioxide laser (OmniGuide, Cambridge, Massachusetts). Multiple masses were resected, and it was confirmed that they emanated from the piriform sinus. Gross examination revealed multiple tan-gray, irregularly shaped tissue fragments measuring 4.1 3 1.2 cm, with 1 area showing smooth, gray mucosa. Sectioning showed tan-gray firm tissue. Histologic analysis demonstratedanodular areaofblandspindlecellproliferationwithout a capsule in the submucosa, with interspersed mature fatty tissue in the periphery (Figure 2). The spindle cells were arranged in a nondescript pattern with meshworks of small vessels (Figure3). No specific architecture, such as a herring bone or hemangiopericytic pattern, was noted. No significant nuclear pleomorphism, mitosis, necrosis, or hemorrhage was present. There was no evidence of dysplasia or malignancy. Immunohistochemical stains were strongly positive for vimentin and CD34 (Figure 4) and negative for smooth muscle antigen, S-100 protein, keratin, and neurofilament in the spindle cells. What is your diagnosis?