Localized cutaneous mucinosis associated with multiple myeloma: a rare presentation

Lichen myxoedematosus (LM), a form of primary cutaneous mucinosis, may present either as localized less severe form called papular mucinosis or diffuse more severe form called scleromyxoedema. The diffuse form is almost always associated with monoclonal gammopathy, whereas localized form is not. We report an atypical case of localized form of LM associated with multiple myeloma in a 66-year-old male, who presented with asymptomatic waxy papular eruption on extremities, which on histopathological examination confirmed the diagnosis of cutaneous mucinosis. After initially being put on steroids and hydroxychloroquine with minimal improvement, patient subsequently presented with encephalopathy and on evaluation revealed hypernatremia, hypercalcemia, hypergammaglobulinemia, reversal of albumin-globulin (A/G) ratio, azotemia, and lytic lesions in skull X-ray. Bone marrow aspiration and biopsy confirmed multiple myeloma. Patient was successfully treated with standard treatment regimen for multiple myeloma with bortezumib and dexamethasone and his skin lesions subsided completely.