Merkel cell carcinoma


Merkel cell carcinoma

A highly aggressive skin tumour, usually of the head and neck, which is most common in the elderly, and 13-fold more common in patients with HIV-1. Merkel cell polyomavirus is clonally integrated at various sites in the genome of most Merkel cell carcinomas.
Associations
Actinic keratoses, Bowen's disease, squamous cell carcinoma, basal cell carcinoma.
 
DiffDx
Small blue-cell tumours—e.g., leukaemia, acute lymphoblastic lymphoma, granulocytic sarcoma, NK/T-cell lymphoma, and metastatic small cell carcinoma from the lung or elsewhere.
 
Prognosis
3-year survival: 68% female, 36% male.
Poor prognosticators
> 30 mm tumour, stage II+, lack of inflammation, Ki-67 (cell proliferation) index of > 50%.
Management
Wide excision, prophylactic lymph node dissection, radiation therapy, chemotherapy.

Merkel cell carcinoma

Cutaneous neuroendocrine carcinoma A highly malignant skin tumor, usually head & neck, most common in the elderly Prognosis Poor, 3-yr survival 68% ♀, 36% ♂ Treatment Wide excision, prophylactic LN dissection, RT, chemotherapy

Mer·kel cell car·ci·no·ma

(mĕr'kĕl sel kahr'si-nō'mă) Rare and highly aggressive skin cancer, with lesions that develop on or just below the skin that are usually found on sun-exposed body areas; appear as painless, firm nodules or tumors; metastasize quickly and spread to other parts of the body, tending toward the regional lymph nodes. Twice as common in older men.