Merkel-Zell-Karzinom

Abstract

Merkel cell carcinoma (cutaneous neuroendocrine carcinoma) is a rare, highly malignant, neuroendocrine tumor of the skin with predominance in older patients. The tumor is most often located in the sun-exposed skin of the head, the neck and -as in our patient - the extremities. Notably, the tumor bears a high risk of an early regional lymph node as well as distant metastases. Clinically, only a presumptive diagnosis of Merkel cell carcinoma can be established. The definite diagnosis is made by histological and immunohistological methods. Surgical excision with a safety margin should be combined with sentinel lymph node biopsy. In advanced tumor stages (lymph node or visceral metastasis), a remission can be achieved by different chemotherapy schedules in combination with radiation. Recently, a previously unknown polyomavirus, named Merkel cell polyomavirus (MCV or MCPyV), has been identified in 80% of Merkel cell carcinomas. In the near future, these novel findings could be utilized to distinguish Merkel cell carcinoma from small round cell cancers and could lead to the development of new therapeutic options.

Unexpected maspin immunoreactivity in Merkel cell carcinoma

“…The 5-year survival rate decreases from 42–52 % in node-positive MCCs to 17–18 % in cases with distant metastases [ 18 ]. In every non-metastatic case (stages I and II), wide excision with safety limits and sentinel lymph node biopsy is recommended, followed by radiotherapy [ 13 ]. In node-positive MCCs (stage III), treatment of the nodal basin with lymphadenectomy and radiotherapy should be performed [ 16 ].…”

“…Although ultraviolet radiation, immunosuppression, and Merkel cell polyomavirus (MCV) infection are considered the main factors responsible for carcinogenesis of MCC [ 5 , 13 ], the molecular mechanism is poorly understood, and the neuroendocrine arhitecture makes the differential diagnosis very difficult. In this paper, we report the pathologic findings, criteria for differential diagnosis, and the particularities of the immunoprofile of MCCs, based on three cases and a comprehensive literature review.…”