Thelansis

 Merkel cell carcinoma (MCC) is a rare and aggressive form of skin cancer in which malignant cells form in the top layer of the skin, close to the nerve endings that sense touch. MCC commonly appears as a painless bluish-red lump on the skin. MCC occurs most often on sun-exposed areas of the skin, such as the head, neck, arms and legs. The absence of distinctive clinical characteristics distinguishes the primary lesion of MCC. The clinical differential diagnosis includes more common lesions, such as epidermoid cyst, basal cell carcinoma (BCC), or even amelanotic melanoma, which are rarely suspected at the biopsy. Merkel cell carcinoma often presents as a rapidly growing, asymptomatic, reddish-blue dermal papule or nodule that grows over several weeks to months. Apoptotic bodies and pagetoid intraepidermal involvement can be found in up to 10% of MCCs. MCCs sometimes have areas of squamatisation and can occur in combination with other epithelial tumors. Nearly 40% are associated wit...