A Case of Primary Malignant Melanoma of the Esophagus with Essential Thrombocythemia

Abstract

A 74-year-old man visited a clinic with dysphagia and weight loss. Esophagogastroduodenoscopy revealed a tumor over the middle and lower thoracic esophagus, and the patient was referred to our hospital for further examination and treatment. Computed tomography (CT) revealed a 9-cm neoplastic lesion with an irregular ulcer ; however, histopathological examination did not show malignant findings. The patient had thrombocytopenia, and the platelet count was high at the first visit to our hospital. Bone marrow biopsy and blood genetic test results revealed essential thrombocythemia, a subcategory of myeloproliferative neoplasms. Thoracoscopic subtotal esophagectomy can be safely performed after controlling the platelet count by cytoreductive treatment with hydroxycarbamide. The patient was discharged without any complications, such as thrombosis and bleeding.

The postoperative pathological diagnosis was primary malignant melanoma of the esophagus, stage II according to the 11th edition of the Japanese Classification of Esophageal Cancer and stage II according to the 8th edition AJCC/UICC staging of cancers of the esophagus and esophagogastric junction. The patient was treated with nivolumab, an immune checkpoint inhibitor, for primary malignant melanoma of the esophagus as adjuvant chemotherapy and hydroxycarbamide, as cytoreduction therapy for essential thrombocythemia.