Consider the following - Carcinoma of the stomach Obesity Insulin resistance Hemochromatosis Which of the above is/are associated with acanthosis nigricans?

Acanthosis nigricans is a brown to black, poorly defined, velvety hyperpigmentation of the skin. It is usually found in body folds,such as the posterior and lateral folds of the neck, the armpits, groin, navel, forehead and other areas. Carcinoma of stomach ,insulin resistance,obesity are associated with this Factors involved in the development of acanthosis nigricans include: Increased circulating insulin. This activates keratinocyte ILGF receptors, paicularly IGF-1. At high concentrations, insulin may also displace IGF-1 from IGFBP. Increased circulating IGF may lead to keratinocyte and dermal fibroblast proliferation. Fibroblast growth factor. Hereditary variants are associated with FGFR defects. Increased TGF, which appears to be the mechanism for malignancy-associated acanthosis nigricans. TGF acts on epidermal tissue the EGFR In conjunction with increased end levels of ILGF, it is likely that perspiration and friction may be necessary predeterminants for lesions. Ref Davidson 23rd edition pg 873