Coal forms from the accumulation of plant debris, usually in a swamp environment. When plant debris dies and falls into the swamp the standing water of the swamp protects it from decay. Swamp waters are usually deficient in oxygen, which would react with the plant debris and cause it to decay.
Porokeratosis is generally considered to be a benign condition though malignant transformation has been seen in all but the punctate variety, necessitating regular followup of patients with porokeratosis (Maubec et al., 2005; Sasson & Krain, 1996).
Porokeratosis of Mibelli: A rare skin disorder characterized by skin lesions that tend to spread and may be located on the limbs, face, genitals and mouth. The condition progresses and regresses spontaneously and mild scarring may result.There is an associated increased risk of skin cancer.orokeratosis of Mibelli: A rare skin disorder characterized by skin lesions that tend to spread and may be located on the limbs, face, genitals and mouth. The condition progresses and regresses spontaneously and mild scarring may result.