Clinical Information
- A carcinoma arising from merkel cells located in the basal layer of the epidermis and occurring most commonly as a primary neuroendocrine carcinoma of the skin. Merkel cells are tactile cells of neuroectodermal origin and histologically show neurosecretory granules. The skin of the head and neck are a common site of merkel cell carcinoma, occurring generally in elderly patients. (holland et al., cancer medicine, 3d ed, p1245)
- 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.
- A rare type of cancer that forms on or just beneath the skin, usually in parts of the body that have been exposed to the sun. It is most common in older people and in people with weakened immune systems.
Codes
C4A Merkel cell carcinoma
- C4A.0 Merkel cell carcinoma of lip
- C4A.1 Merkel cell carcinoma of eyelid, including canthus
- C4A.2 Merkel cell carcinoma of ear and external auricular canal
- C4A.3 Merkel cell carcinoma of other and unspecified parts of face
- C4A.4 Merkel cell carcinoma of scalp and neck
- C4A.5 Merkel cell carcinoma of trunk
- C4A.6 Merkel cell carcinoma of upper limb, including shoulder
- C4A.7 Merkel cell carcinoma of lower limb, including hip
- C4A.8 Merkel cell carcinoma of overlapping sites
- C4A.9 Merkel cell carcinoma, unspecified