Merkel cell carcinoma

Neuroendocrine carcinoma of the skin, also known as Merkel cell carcinoma, is a rare malignant cutaneous tumor seen in elderly patients. Its usual location is on the head, neck and extremities. The tumor is composed of small round cells with scanty cytoplasm arranged in a trabecular pattern, or in ill-defined nodules or in a diffuse pattern. The tumor cells contain cytoplasmic membrane-bound dense core granules resembling neurosecretory granules. --2002