Primary Small Cell Undifferentiated (Neuroendocrine) Carcinoma of the Maxillary Sinus

Primary small cell neuroendocrine carcinoma (SNEC) of the paranasal sinuses is an extremely rare and distinctive tumor with aggressive clinical behavior. Moreover, SNECs originating in the head and neck region have been reported to be highly aggressive and to have a poor prognosis. This report describes a patient with a maxillary sinus SNEC who was successfully treated with neoadjuvant chemotherapy and concurrent chemoradiotherapy. 1. Introduction Carcinoma developing in the paranasal sinuses accounts for approximately 0.3% of all cancers [1]. Squamous cell carcinoma is by far the most common malignancy, followed by adenocarcinoma. Extrapulmonary small cell neuroendocrine carcinoma (EPSNEC) of sinonasal tract is rare. The first case of SNEC of the paranasal sinuses was reported by Raychowdhuri [2] in 1965. SNECs originating in the head and neck region have been reported to be highly aggressive and to have a poor prognosis. This report describes a patient with a maxillary sinus SNEC who was successfully treated with neoadjuvant chemotherapy and concurrent chemoradiotherapy. The clinical and pathologic features of the tumor and the optimal treatment of this patient are discussed. 2. Case Report A 70-year-old female presented to the oral and maxillofacial department with gradual onset of right cheek swelling around the right gingival and a painful mass for about 1 month. Physical examination showed hard cheek swelling (Figure 1) and epiphora of the right eye, but the patient’s eye movement was normal and she did not have any double vision. The skin around the right eyelids was regular and not reddish, whereas the right posterior alveolar gingival was ulceration ( ) cm, irregular, and reddish in areas (Figure 2). No history of nasal bleed, nasal congestion, and pus from ears. Clinically the patient had an enlarged right submandibular lymph node measuring approximately 3？cm in diameter. The patient was admitted, and imaging studies were performed. Figure 1: Preoperative right cheek swelling. Figure 2: Preoperative intraoral swelling and ulceration. Computed tomography (CT) scan of head showed a large mass measuring approximately 6？cm in diameter in the right maxillary sinus invading the right orbit, ethmoid sinus, and the skin of the cheek (Figures 3(a) and 3(b)). Histologic examination of biopsy sample stained sections showed mucosal tissue bits with features suggestive of poorly differentiated squamous cell carcinoma/neuro-endocrine carcinoma and immunohistochemistry was advised for further evaluation. Immunohistochemical staining was performed on the