Subungual(nail) melanoma: symptoms, stages, photos
Subungual melanoma is a type of skin cancer that occurs under the nails. It is a rare form of melanoma that develops unrelated to sun exposure.
Many people who find a spot under their fingernail begin to search the Internet (or send photos to Reddit), what could it be? And it turns out that this may be a fatal disease - subungual or nail melanoma.
Subungual melanoma is a type of skin cancer that occurs under the nails. It is a rare form of melanoma that develops unrelated to sun exposure. Of the total number of melanomas, the proportion of this tumor is only 2% [1, 2, 3]. The indicator is quite low, but this does not negate the possibility of getting sick.
For representatives of other skin phototypes other than the 2nd, the chances may vary greatly. Representatives of the Mongoloid and Negroid races have a higher (up to 40%) chance of getting melanoma of the nail bed [4, 5].
Where does nail melanoma appear more often? The tumor affects the big toes more often.
What does a subungual melanoma look like? Photos and signs.
All the pictures below have histological confirmation, and are not taken from the Internet. The source is indicated in square brackets. There are 2 most common signs:
Most often, nail melanoma manifests itself in the form of a strip of brown or black color. The strip starts from the nail roller and ends at the edge of the nail. This condition is called longitudinal melanonychia. Some medications can lead to the appearance of such bands – retinoids and Docetaxel (Taxotere) . This sign can also be in conditions unrelated to melanoma, for example, with a fungal lesion of the nail, a pigmented nevus of the nail bed.
The most common sign of this type of melanoma is Hutchinson's symptom - the transition of pigmentation to the nail roller or finger tip. In 7 of the 8 images presented below, this feature is visible. At the same time, it cannot be unequivocally stated that this symptom occurs only with melanoma. It can also be observed with a transparent cuticle .
Subcutaneous pigmented nevus in a 13-year-old boy 
Subungual melanoma of the I st., 0.2 mm according to Breslow 
8 cases of subungual melanoma in situ (initial stage)