[Severe necrotizing myopathy subsequent to Merkel cell carcinoma]

Merkel cell carcinoma (MCC) is a rare tumour with a poor prognosis. Rare cases of paraneoplastic neurological syndrome have been associated with this type of tumour, namely myasthenic syndrome of Lambert-Eaton and encephalomyelitis. We report the first case of severe necrotizing myopathy with anti-Hu antibodies complicating MCC.

We describe the case of a 58-year-old woman with Merkel cell carcinoma (MCC) of the forearm complicated by severe necrotizing myopathy associated with the presence of anti-Hu antibodies. This myopathy occurred 3 months after complete remission of MCC. The patient was treated with high-dose corticosteroids combined with two intravenous infusions of immunoglobulins. Her neurological status deteriorated despite this treatment. Pararaneoplastic syndrome (anti-Hu antibodies, necrotizing myopathy) complicating MCC was suspected. There was no visible tumour relapse. After multidisciplinary discussion, it was decided to supplement treatment with chemotherapy (carboplatin and VP-16). The patient died 20 days after the first course of chemotherapy.

Severe necrotizing myopathy with anti-Hu antibodies may be added to the list of possible paraneoplastic syndromes associated with Merkel cell carcinoma.