2021 Volume 60 Issue 6 Pages 337-343
Background : Merkel cell carcinoma (MCC) in the oral region is very rare and has been reported to show spontaneous regression. We report a case of MCC that was detected at the lingual margin, which disappeared spontaneously from the primary site.
Case : A man in his 40s visited clinic complaining of a swelling on the right lingual margin. The tumor disappeared by 2 weeks, however, it recurred and biopsy of the recurrent tumor revealed atypical cells below the squamous epithelium. Immunohistochemistry revealed positive staining for neuroendocrine markers and the tumor was diagnosed as a neuroendocrine tumor, and resection of the right side of the tongue was performed with cervical lymph node dissection. Atypical cells were found in the lymph nodes, but no atypical cells were found in the resected tongue specimen, suggesting spontaneous regression of the primary tongue tumor. The diagnosis of MCC was made based on the findings of immunohistochemistry and electron microscopy, and the spontaneous regression. Chemotherapy and radiation therapy were administered, and no recurrence has been observed until the time of writing.
Conclusion : Since the differential diagnosis of the lymph node findings, it is necessary to make a comprehensive judgment by immunohistochemistry and electron microscopy.
