A Case of Merkel Cell Carcinoma / 대한피부과학회지

ABSTRACT

Merkel cell carcinoma is an uncommon malignancy originally called "trabecular carcinoma" by Toker in 1972. Although the exact origin of the Merkel cell is unknown, it probably arises from neuroendocrine cell of the basal epidermis. It then grows vertically into the dermis and subcutaneous tissue. The tumor usually affects older persons, with a median age at presentation of 66 years. Although its cause is unknown, its propensity to occur on the head, neck, or extremities suggests that sun exposure may play a role. We report a case of a 58-year-old woman who showed a solitary dusky red-colored tumor on the right upper arm. The tumor had rapidly grown since 2 months ago but there was no evidence of regional lymph node and distant metastases. Microscopically, the tumor cells were uniform with round to oval shaped nucleus and scanty cytoplasm, and showed trabecular, anastomosing cord-like arrangement mainly in the dermis and subcutaneous tissue. Ultrastructually, membrane-bound neurosecretory granules were found in the cytoplasm and characteristic perinuclear filaments were retained in each tumor cell. We performed wide local excision with 3cm margin and prophylactic radiation therapy.