Ectopic Cushing??s Syndrome Resulting From Small Cell Neuroendocrine Carcinoma After Thymus Radiation in Infancy

Abstract

A 16-year-old boy is described who presented with Cushing's syndrome resulting from a highly malignant neuroendocrine tumor of the thymus. He underwent radiation therapy to the thymus at 6 months of age, a common procedure at the time to prevent crib death. This is the first report of the triad of childhood radiation to the thymus, thymic neuroendocrine carcinoma, and ectopic Cushing's syndrome. Childhood thymic neuroendocrine cancers are rare, and a search of the literature suggests there could be fewer than 10 with ectopic Cushing's syndrome. Despite the absence of radiation histories in articles about thymic cancers, the authors feel the prevalence of cancer after childhood radiation to the thymus could be significantly underreported, because an estimated 1 million infants and children were treated well into the 1970s and, like this rare case, are still at risk.