It is a common low grade malignancy that origanates in the pilo sebaseous glands.
It resembles Squamous cell carcinoma, and considered a varient of invasive squamous cell carcinoma.
Synonyms:

Self healing carcinoma
Molluscum pseudocarcinomatosum
Molluscum sabecum
Verrucoma

Differential diagnosis:

Actin keratosis
Molluscum contagiosum
Muir-Torre Syndrome
Squamous cell carcinoma
Verrucous

Etiology:

Exposure to sunlight
Exposure to Pitch, tar.
Trauma
Human Papilloma Virus
Genetic factors
Immunocompramised status

Clinical  Features:

Age: All ages are equally affected.
Sex: M>F
Race: White>Black
Common sites on [...]