(advertisement) Excerpt from Merkel Cell Carcinoma Synonyms, Key Words, and Related Terms: MCC, trabecular carcinoma, small cell carcinoma of the skin, primary cutaneous neuroendocrine carcinoma Please click here to view the full topic text: Merkel Cell Carcinoma Background: Merkel cell carcinoma (MCC) is a rare, aggressive, primary skin cancer exhibiting neuroendocrine differentiation. Several synonyms exist; however, the term MCC is still most commonly used in view of the many similarities of the constituent tumor cell to the normal Merkel cell (MC) of the skin. In 1875, the German anatomist and pathologist Friedrich Sigmund Merkel described Tastzellen (touch cells) in the skin of the snouts of moles and pigs and proposed that they had a mechanoreceptor function. In human development, MCs appear as early as the 8th gestational week, possibly being derived from a primitive epidermal stem cell. MCs are present in high numbers on the lip, the hard palate, the palms, the finger pads, the proximal nail folds, and the dorsum part of the feet. MCs have a predilection for perifollicular areas in the skin; confirmed reports exist of MCs free in the dermis, but they are most easily identified in the basal layer of the epidermis. Normal MCs in skin have several proposed functions, including induction or stimulation of perifollicular or dermal nerve plexuses via a direct complex, stimulation of keratinocyte proliferation and maintenance of their differentiation, histogenesis of the nail, and release of various bioactive substances to the dermis. | |
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