A Case of Adenocarcinomatous Transformation of a Sacrococcygeal Teratoma in an Adult / 대한내과학회지

ABSTRACT

Sacrococcygeal teratoma (SCT) is an unusual tumor in adults. The incidence of malignant transformation of this tumor increases when its excision is delayed beyond 1 month of age. We report an uncommon case of adenocarcinoma arising within the colonic mucosa of a mature teratoma of the sacrococcyx in a 44-year-old male. The patient received surgical resection for a sacrococcygeal mass in a local hospital and was diagnosed with adenocarcinoma arising from SCT. He was referred to our hospital for further treatment and received chemotherapy as adjuvant treatment. After 4.5 years, the coccygeal mass recurred on follow-up imaging workup, and surgical resection was performed. On pathologic work-up, residual disease at the resection margin was identified microscopically. Pathologic diagnosis was a primary adenocarcinoma arising from the colonic mucosa within a mature teratoma. The patient received adjuvant-chemotherapy and radiotherapy and has been followed up.