Spontaneous Regression of Dermal Metastases in Merkel Cell Carcinoma

Abstract

Introduction: Merkel cell carcinoma (MCC) or cutaneous neuroendocrine carcinoma is a rare and aggressive cutaneous malignancy. Interestingly, despite its aggressive nature, complete spontaneous regression of MCC has been reported, mostly of the head and neck sites, and after biopsy or fine-needle aspiration sampling. There has been speculation that the biopsy of MCC may trigger complete spontaneous tumor regression via stimulation of the immune system. Spontaneous regression of metastatic MCC lesions after the excision of the main lesion, however, has not been reported in English literature.

Presentation of case: We report an extremely rare case of MCC of the left gluteal region with left inguinal lymphadenopathy and metastatic dermal nodules who underwent excision of the main lesion and was noted to have spontaneous regression of his dermal metastases post-operatively.

Conclusions: Spontaneous regression of MCC remains a poorly understood phenomenon. Further research into the histopathological features and immunity status should be considered to elucidate the mechanism underlying this phenomenon, as it will potentially be life-saving for patients with this rare malignancy, whose median survival will otherwise be measured in months.