"Pellagra" like skin lesion occurs with:
Systemic Mastocytosis
Bronchial carcinoid
Colorectal villous adenoma
Medullary thyroid carcinoma
Carcinoid tumors produce the vasoactive substance, Serotonin.A pellagra-like syndrome is probably caused by diversion of large amounts of tryptophan from the synthesis of Vitamin B3 niacin, which is needed for NAD production, to the synthesis of serotonin and other 5-hydroxyindoles(ref:Harper's 27/e p458)
All India exam