[Clinical analysis of 11 patients with neuroendocrine carcinoma in maxillofacial region]

Objective: To investigate the clinicopathological features, treatment and prognosis of maxillofacial neuroendocrine carcinoma. Methods: A total of 11 patients with maxillofacial neuroendocrine carcinoma diagnosed in the Department of Pathology of The First Affiliated Hospital of Zhengzhou University from December 2010 to July 2022 were retrospectively enrolled, including 8 males and 3 females, aged (65.2±9.5) years (ranged from 49 to 87 years), with a disease course of 0.5 to 6.0 months. The clinicopathological data including head and neck CT, MRI and treatment methods were analyzed. Results: Submandibular gland and maxilla were involved in 3 cases, parapharynx in 2 cases, and face, tongue root and soft palate in 1 case respectively. Clinically, the initial symptom is a rapidly growing painless or tender mass, which may be accompanied by restricted mouth opening, dysphagia, and local numbness after invasion of masticatory muscles and nerves. The tumors were all invasive and low-density, with unclear boundaries from the surrounding tissues. Among the patients, 9 received surgical treatment, and 5 received adjuvant treatment after surgery (2 received chemotherapy, 3 received radiotherapy+chemotherapy). According to the 5th edition of the World Health Organization classification of head and neck tumors in 2022, there were 1 case (1/11) with poorly differentiated large cells and 10 cases (10/11) with poorly differentiated small cells. Histologically, the macrocell type is composed of large cells with rough chromatin, obvious vacuolar nucleolus, protruding nucleolus, and necrosis. The small cell type is dominated by small blue round cells with neuroendocrine characteristics, with active growth and multifocal necrosis. Immunohistochemical staining showed that cytokeratin (CK), epithelial membrane antigen (EMA) and synaptophysin (Syn) were diffusively expressed, 10 cases expressed CD56, 8 cases expressed p63, 6 cases expressed weakly punctated chromograin-A (CgA), and S-100 was not expressed. The Ki-67 index ranges from 20 to 90 percent. By the end of follow-up (0.5 to 127.0 months), 3 patients were alive, and the mean progression-free survival (21.0 months) of postoperative chemoradiotherapy patients was significantly longer than that of surgery and/or chemotherapy alone (3.3 months). Conclusions: Maxillofacial neuroendocrine carcinoma is characterized by low differentiation of small cells, high degree of malignancy and poor prognosis. Radical surgery combined with chemoradiotherapy has better local control effect.