[Dermatomyositis as the first manifestation of small cell carcinoma: case report and literature review].

Dermatomyositis is an autoimmune inflammatory myopathy associated with dermatologic findings. Its association with neoplasms is widely reported and has been shown to be higher in lung cancer, particularly small-cell carcinoma, probably as it originates from neuroendocrine cell precursors, as well as breast and ovarian cancer. The low frequency of dermatomyositis makes it difficult to suspect the underlying lesions among the diagnostic possibilities of systemic diseases with cutaneous manifestations. Therefore, the high probability of a neoplasm should always be considered, with reports of up to 75% in the eastern population and about 40% in general. In this report, we present a rare case of dermatomyositis with lesions in a shawl-like distribution, as a symptomatic debut of a small cell lung carcinoma.