Atypical lipomatous tumor mimicking giant fibrovascular polyp of the esophagus: report of a case and a critical review of literature.

An 81-year-old man presented to the emergency department with a mass protruding from his mouth after an episode of emesis. A computed tomography scan showed a hypodense, polypoid structure with a fatty component. The long polyp was attached by a narrow stalk to the cervical esophagus. A 14.0-cm slender mass resembling a giant fibrovascular polyp (GFP) of the esophagus was resected. The microscopic, immunohistochemical, and molecular findings were, however, those of an atypical lipomatous tumor (ALT). Atypical lipomatous tumor of the esophagus is a rare, low-grade malignant neoplasm, with a potential for local recurrence and, in most instances, presents as a large intraluminal polyp mimicking a GFP. Cases reported in the literature as primary myxoid liposarcomas of the esophagus are in all likelihood examples of ALT with myxoid change. A recent case reported as a GFP with karyotypic abnormalities on comparative genomic hybridization is also most likely to be an ALT mimicking a GFP. Pathologists need to be aware of the pitfalls in the diagnosis of ALT of the esophagus and should carefully evaluate the adipocytic component of these lesions.