Neurofibromatosis, cutan melanoma and hyper-thyroidism in a HCV positive patient treated with interferon

Introduction: Development of malignant melanoma in neurofibromatosis is rare, but the association of these two disorders seems reasonable in theory, as both are abnormalities of a neural crest origin.

Case report: A 43-year-old woman had been managed with neurofibromatosis (NF-1) for 16 years, when she presented increased serum gamma-glutamyltransferase and serum alkaline phosphatase activity at regular check-up. Anti-HCV antibody positivity was detected. Physical investigation revealed an expanding pigmented lesion on her back histologically proved to be cutan melanoma. Interferon treatment was applied, which is also widely used for HCV infection. During interferon therapy she lost 8 kilograms in half a year and serum alkaline phosphatase increased again. Neither metastasis nor recurrence of melanoma was found, but hyperthyreoidism was diagnosed. A rapid clinical and laboratory improvement was observed for thyreostatic treatment.

Half year later she presented with cough and a pulmonary mass on X-ray. The surgically removed tumor was diagnosed as metastasis of malignant melanoma. Cytostatic treatment was applied. Four years after the diagnosis of melanoma she died of apoplexy. During the autopsy there was no sign of either melanoma or liver disease.

Conclusion: Interferon therapy was beneficial for not only the cutan melanoma, but also for the viral hepatitis C. In case of significant loss of body weight even in a patient with history of malignant disease other causes should also be searched, as hyperthyreoidism, especially during interferon therapy.