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).
Top 10 unbelievable historical concurrencies. Porokeratosis is an uncommon type of skin condition characterized by scaly, discolored, dry specks or patches on certain parts of the body.t is possible to have a single lesion or multiple abnormal spots on the body. Lesions typically do not change in size and shape over time, and any changes that do occur can be signs of developing skin cancer. Skin carcinomas that arise due to porokeratosis are usually characterized by hard, scaly, dark-colored lesions.