Mucocutaneous paraneoplastic syndromes.

Mucocutaneous paraneoplastic syndromes represent a group of dermatoses of variable morphology, pathology, and etiology that can occur as idiopathic conditions or in association with a visceral malignancy. These conditions can be categorized with respect to their predominant pathologic change: dermal "depositions," neutrophilic dermatoses, papulosquamous disorders, proliferative reactions, reactive erythemas, vacuolar degeneration of the basal layer, vasculitis, and vesiculobullous disorders. Some of these dermatoses occur more frequently in patients with hematologic malignancies whereas others are more prevalent in patients with solid tumors. The major clinical characteristics and commonly associated malignancies in patients with mucocutaneous paraneoplastic syndromes are reviewed. Suggested workups to evaluate for cancer in patients with these dermatoses are summarized. The appearance of a mucocutaneous paraneoplastic syndrome can either precede, occur concurrently with, or follow the detection of an associated neoplastic process. Therefore, the dermatosis can be the presenting feature of a previously unsuspected neoplasm or the earliest sign of recurrent cancer in an oncology patient. When the possibility of a mucocutaneous paraneoplastic syndrome is entertained, the diagnosis of the dermatosis should be confirmed either based on the clinical morphology of the lesions, the pathologic changes observed after lesional biopsy, or both. Once the diagnosis of a malignancy-associated dermatosis has been established, either an appropriate evaluation for an asymptomatic neoplasm in a cancer-free individual or an investigation for recurrence of malignancy in an oncology patient can be initiated.