Paraneoplastic plaque-like cutaneous mucinosis: a case report.

Plaque-like cutaneous mucinosis (PCM) is a rare disorder of dermal mucin deposition. Some patients with PCM will be found to have an associated malignancy. We report the case of a 72-year-old man presenting with new onset pruritic, waxy-appearing erythematous and skin-colored papules and nodules coalescing into plaques on his shoulder, scalp, and forehead. Skin biopsy revealed cutaneous mucinosis. Despite conservative treatment, his skin lesions progressed, and he was found to have an occult malignancy of pancreatobiliary origin. After several months of chemotherapy, his skin lesions showed progressive improvement. To our knowledge, this is the third reported case of paraneoplastic PCM and the first reported to occur in association with underlying adenocarcinoma of pancreatobiliary origin. PCM may occasionally represent a paraneoplastic dermatosis. This case highlights the importance of a search for occult malignancy in such patients.