Significant Neutrophilic Emperipolesis in SquamousCell Carcinoma

A 53-year-old man was admitted for tooth mobility. A mass was identified at the tooth base by CT. Histopathology of the excisionalbiopsy revealed a moderately differentiated squamous cell carcinoma. Many intact neutrophils were observed within the malignantcell cytoplasm. The patient underwent partial maxillectomy and bilateral neck dissection. Significant neutrophilic emperipolesiswas detected in the resected material. Four tumor recurrences developed in the head and neck region during follow-up. Surgeryand chemoradiotherapy was performed. The latest tumor recurrence occurred in the peripharyngeal and the posterior parotidealregion. The patient was started on pembrolizumab therapy and nearly complete treatment response occurred. Pembrolizumabwas discontinued due to the adrenal insufficiency and pulmonary tuberculosis that developed as a treatment side effect.Pembrolizumab was commenced again when tumor recurrence occurred. The patient is currently alive with ongoingpembrolizumab and antituberculous treatment. We present this case to remark the presence of a significant neutrophilicemperipolesis in the squamous cell carcinoma of the hard palate and maxilla which is rarely encountered. Emperipolesis maypredict tumor behavior and the consequences of immune-modulating treatment response in squamous cell carcinomas of thehead and neck in regard to thefindings of our case.