Diseases of the skin and subcutaneous tissue (dermatology)

A sebaceous nevus is a hamartoma of the sebaceous glands, usually present from birth, but there have been cases where this developmental defect was latent until puberty and only became clinically apparent with the onset of the latter.

Cystic epithelioma (syn.: proliferating trichilemmal cyst, pilar tumor) is a rather rare tumor, mainly occurring in people over 40 years of age, although the age range is quite wide - from 26 to 87 years.

Pilomatricoma (syn. Malherbe's necrotizing calcified epithelioma) is most often found in childhood and adolescence, mainly on the face or in the shoulder girdle, in the form of a solitary tumor reaching a size of several centimeters, covered most often by normal skin with a smooth surface, protruding above the skin level, of a very dense consistency. It grows slowly over many years, does not ulcerate.

Trichilemmomas clinically resemble basalioma or seborrheic keratosis and are usually histological findings. The tumor is usually solitary, small in size, predominantly localized in the facial area, somewhat more often in men than in women, the average age of patients is 59 years.