[Coexistence of acromegaloidism and lung cancer]

Acromegaloidism is a condition characterized by features of acromegaly without biochemical evidence of excessive growth hormone (GH) production. Insulin resistance is one of the possible etiologies. We report the case of a patient with acromegalic features, a left lung neoplastic process, generalized acanthosis nigricans and severe insulin resistance. Normal IGF 1 and GH inhibition below 1 ng/ml by the oral glucose tolerance test ruled out the diagnosis of acromegaly. Acanthosis nigricans (AN) may be present as a paraneoplastic syndrome or may be associated to benign pathology in which insulin resistance is involved. Acromegaloidism has been reported in patients with severe insulin resistance as we are describing here. It is possible that very high insulin levels can stimulate excessive acral growth acting through insulin receptors that retain the ability to mediate anabolic effects, or alternatively through the IGF1 receptor. We found no data of acromegaloidism as a paraneoplastic syndrome. To summarize, we report a case of severe insulin resistance, pseudoacromegaly and AN, coexisting with a lung carcinoma. Acromegaloidism and AN appear to be due to insulin resistance, even though in this patient we cannot exclude that AN could be a paraneoplastic syndrome.