Epithelioid Hemangioendothelioma of the Maxillary Sinus.

The clinical course and pathologic features of a 72 year old female who presented with epistaxis are presented. Radiographic findings were notable for a large, soft tissue lesion filling the maxillary sinus with significant bony erosion and expansion. The patient was ultimately diagnosed with epithelioid hemangioendothelioma (EHE) and underwent endoscopic resection. She has no evidence of local, regional or distant recurrence 14 months post-surgery. The rarity of this neoplasm, the unusual anatomic location and non-specific symptoms present diagnostic and management challenges. Epithelioid vascular tumors encompass a spectrum of benign and malignant tumors. EHE itself is thought to have an intermediate malignant behavior pattern, though cases with indolent behavior have been reported. Differentiation of EHE from other lesions has historically based on histopathology. Additionally, recent studies have described a recurrent genetic fusion WWTR1-CAMTA1 in EHE, involving t(1;3) (p36;q25). This represents the second reported case of EHE arising in a paranasal sinus. The histopathologic findings of this lesion are reviewed.