Sinonasal Glomangiopericytoma: A Report of Two Cases.

Sinonasal glomangiopericytoma (GPC) is a rare mesenchymal tumor that is seen exclusively in the sinonasal region, which shows perivascular myoid differentiation. Here, we describe two cases of sinonasal glomangiopericytoma. The first case was a 62-year-old female patient with right-sided nasal obstruction and headache. Endoscopic examination revealed a polypoid mass in the right nostril. Surgical removal revealed spindle cell proliferation with staghorn vasculature surrounded by perivascular hyalinization beneath an intact ciliated respiratory epithelium. Tumor cells were reactive to smooth muscle actin (SMA) and had nuclear staining for beta-catenin, consistent with sinonasal glomangiopericytoma. The second case was reported in a 65-year-old female patient who complained of right ear discharge with recurrent ear infections. Imaging revealed an opacification of the left ethmoid and sphenoid sinuses that was surgically removed and showed uniform spindle cells arranged in a whorling pattern with prominent vasculature and perivascular hyalinization with positive staining with SMA and nuclear reactivity to beta-catenin. Sinonasal glomangiopericytoma is a rare mesenchymal neoplasm that can present with various clinical features, including headache, nasal obstruction, ear infection, and ear discharge. Surgical excision is the treatment of choice with rare recurrence.