"Pellagra" like skin lesion occurs with:
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)
Systemic Mastocytosis
Bronchial carcinoid
Colorectal villous adenoma
Medullary thyroid carcinoma
All India exam