The Torre or Muir-Torre syndrome consists of certain types of sebaceous neoplasms of the skin, with or without keratoacanthomas, and one or more low-grade visceral malignancies in the absence of other predisposing factors. The sebaceous tumors are relatively uncommon or rare: sebaceous adenoma, sebaceous epithelioma, basal cell epithelioma with sebaceous differentiation, and sebaceous carcinoma. Sebaceous hyperplasia and hamartomas such as nevus sebaceus of Jadassohn, with or without a sebaceous epithelioma within it, are not a defining part of this syndrome. Sebaceous hyperplasia is common in elderly light-complexioned people with or without this syndrome. Nevus sebaceus of Jadassohn is not rare and is predisposed to the development of other neoplasms within it, including occasionally a sebaceous epithelioma. Colonic polyps are frequently present. Muir-Torre syndrome requires recognition because affected patients are at risk of multiple primary malignancies. The skin lesions may be the first sign of this syndrome, although more often its cutaneous signs follow the diagnosis of at least the first visceral malignancy. The Muir-Torre syndrome portends the greater possibility of a favorable prognosis than might be anticipated otherwise because the visceral cancers are usually low-grade malignancies. However, they are often multiple, so identifying such patients will affect their management in a few ways. Because these indolent visceral malignancies tend to permit prolonged survival, even melastatic disease may respond well to aggressive surgical treatment. The sebaceous cancers in this syndrome, like the visceral malignancies, are less aggressive than their counterparts unassociated with this syndrome. Because this syndrome is inherited in an autosomal dominant manner, identifying one patient means delineating an entire family, which should be investigated. This syndrome may be caused by a defective mismatch DNA repair gene.
