食道カルチノサルコーマの化学放射線療法後の肉腫残存に対する切除術：症例報告

Esophageal carcinosarcoma is a rare malignancy with both carcinomatous and sarcomatous components. Radical resection is the treatment of choice; however, there is disagreement about whether to perform perioperative chemotherapy or chemoradiotherapy. We report a case of radical resection of esophageal cancer with a residual sarcomatous component in the operative specimen following chemoradiotherapy for suspected esophageal carcinosarcoma.

A 60-year-old man with a chief complaint of dysphagia who underwent esophagogastroduodenoscopy was diagnosed with esophageal squamous cell carcinoma and treated with definitive chemoradiotherapy. Nine months later, esophagogastroduodenoscopy showed an elevated lesion, and biopsy confirmed a pathological diagnosis of spindle cell sarcoma. We hypothesized that the final course of chemoradiotherapy therapy would eliminate the esophageal squamous cell carcinoma but allow the sarcoma to progress quickly. No metastasis was detected, and the tumor was suspected to be highly malignant; therefore, esophagectomy was performed as part of a 3-field lymphadenectomy. The histopathological diagnosis was esophageal cancer with a residual sarcomatous component in the operative material. Postoperative examination of the original esophageal squamous cell carcinoma revealed poorly differentiated keratinocytes, indicating the presence of mixed sarcomatous components. We concluded that the carcinomatous component disappeared following chemoradiotherapy for esophageal carcinosarcoma, whereas the sarcomatous component remained.

This case represents an esophageal carcinosarcoma in which the carcinomatous component completely regressed after definitive chemoradiotherapy, whereas the sarcomatous component persisted and required surgical resection. This finding indicates a differential therapeutic response between the two components of carcinosarcoma and provides important insight into the management of this rare tumor.