A Rare Case of Intravascular Papillary Endothelial Hyperplasia of the Hypopharynx: A Case Report and Literature Review

Abstract

Intravascular papillary endothelial hyperplasia (IPEH), also known as Masson's hemangioma, is a rare benign vascular lesion characterized by an unusual pattern of endothelial proliferation within a thrombosed vessel. Histologically, IPEH is defined by prominent intraluminal papillary structures composed of a single layer of enlarged endothelial cells, lacking cytologic atypia, mitotic activity, and necrosis. Here, we report a rare case of IPEH identified in the hypopharynx of a 56-year-old male patient, incidentally, on imaging for evaluation of unrelated upper back pain. We describe the clinical presentation, histopathologic findings, differential diagnosis, and review of the current literature to enhance recognition and management of this entity in rare/unusual sites.

Keywords: head and neck neoplasms; hypopharynx; intravascular papillary endothelial hyperplasia (masson's tumor); papillary lesions; vascular proliferation.

Figure 1. MRI of the C-spine revealed a 1.6 x 1.3 x 2.2 cm submucosal mass in the left posterior lateral hypopharynx (lateral and cross-section images).

Figure 2. High magnification images show that the papillae consist of cores of fibrin or fibrous connective tissue and are lined by a single layer of plump endothelial cells. Thrombosis is seen at the bottom right corner of the image and numerous hemosiderin-laden macrophages, compatible with prior hemorrhage.

Figure 3. Low-power magnification of the lesion shows numerous papillary structures within a vascular space with surrounding hemorrhage and thrombosis.