Successful multimodal therapy for undifferentiated carcinoma with neuroendocrine differentiation in the clival region

Abstract

Carcinomas with neuroendocrine differentiation include tumor components with characteristics of neuroendocrine tumors of carcinomas of the lung, gastrointestinal tract, prostate, and breast. No clear definition or treatment has been established. A 66-year-old female was admitted to our hospital for a sore throat and otalgia. Magnetic resonance imaging showed a locally invasive tumor with a diameter of 45 mm in the clival region. Histopathological examination revealed that the tumor consisted of densely packed undifferentiated tumor cells with high mitotic activity. Two cellular components were present: one proliferating in solid nests that were immunopositive for cytokeratin, and the other that was diffusely proliferating and immunopositive for neuroendocrine markers. The tumor was thus diagnosed as undifferentiated carcinoma with neuroendocrine differentiation. The patient was treated with four cycles of cisplatin and etoposide and a total of 70 Gy radiotherapy. A complete response was achieved and maintained without therapy for 16 months. Metastasis to the lymph nodes, liver, and bone then appeared, and a lymphadenectomy revealed undifferentiated carcinoma without neuroendocrine differentiation. The patient died because of the tumor 36 months after the initial diagnosis. Because undifferentiated carcinomas with neuroendocrine differentiation in the skull are exceedingly rare, we report this case in which the tumor was controlled with chemoradiotherapy.