A CASE REPORT OF SINONASAL UNDIFFERENTIATED CARCINOMA WITH SYNCHRONOUS BREAST CANCER.

Abstract

Purpose To investigate the occurrence and clinical features of sinonasal undifferentiated carcinoma (SNUC). Patient Case A 61-year-old Philippine female was referred to Oncology for a palpable breast mass. The biopsy demonstrated an intermediate-grade infiltrating ductal carcinoma. Markers for estrogen receptor and Her2 /neu were positive. The patient also gave a history of recent-onset epistaxis and decreased hearing. Bilateral enlarged cervical nodes were readily apparent on examination. She reported these as enlarging for the last 6 months. CT scan of the neck was pertinent for a large nasopharyngeal mass at the level of the palatine tonsils with extensive bilateral upper cervical adenopathy (up to 3.8 cm). CT scans of the head, chest, abdomen, and pelvis plus a bone scan were negative for metastatic disease. She was seen in consultation by an ENT who biopsied the nasal mass, yielding the diagnosis of SNUC. The patient is now postmastectomy and is to begin weekly paclitaxel, cisplatin, trastuzumab, and cranial radiotherapy. Discussion SNUC is a rare malignancy arising from the schneiderian mucosa first described by Frierson in 1986. Aggressive growth, poor prognosis, and lack of optimal management guidelines characterize it. Men are affected more often than women, with an average age of 55. Regional nodal metastases are present at diagnosis in up to 50% of cases. Bone appears to be the most common site of distant metastasis. This case is more unusual in that the tumor developed in the nasopharynx rather than the typical sites of the ethmoid or sphenoid sinuses (which are lined by schneiderian mucosa). The differential diagnosis of nasopharyngeal masses includes nasopharyngeal cancer, lymphoma, plasmacytoma, or metastasis. SNUC must be differentiated from olfactory neuroblastoma, sinonasal endocrine carcinoma, and primary sinonasal nasopharyngeal-type undifferentiated carcinoma by microscopy and immunohistochemistry. Despite previous beliefs, SNUC is not associated with EBV infection. Optimal therapy should include an aggressive multimodality approach combining platinum-based chemotherapy with radiation and craniofacial resection. Small studies have demonstrated 2-year survival figures approaching 64% with current therapy.