Pellagra From Tryptophan Depletion in Carcinoid Syndrome due to a Pulmonary Atypical Carcinoid Neuroendocrine Tumor

ABSTRACT Pellagra may complicate functioning pulmonary atypical carcinoid and present as a subtle acral dermatosis rather than the classical photo‐distributed rash. In neuroendocrine tumor patients with chronic diarrhea and new skin changes, clinicians should suspect niacin deficiency and consider empiric nicotinamide, even when niacin assays are unavailable.