Hypertrophic osteoarthropathy associated with metastatic melanoma.

Hypertrophic osteoarthropathy (HOA) is one of the paraneoplastic syndromes most commonly associated with non-small-cell lung cancer. Although pulmonary metastasis is the second most common initial site of melanoma metastasis, HOA is rarely detected in patients with metastatic melanoma in the lung. We report a case of a 45-year-old woman with advanced melanoma who developed HOA after her disease had progressed through first-line systemic therapy. The patient's diagnosis of HOA was made on the basis of digital clubbing, arthralgia, pain, joint effusion and periosteal bone formation on X-ray with negative rheumatologic laboratory studies. Only six cases of HOA in metastatic melanoma have been reported previously. This diagnosis should be considered with lung metastases and the presentation of polyarthralgia with appropriate laboratory and imaging findings. Interestingly, the patient responded to bisphosphonates and second-line chemotherapy with carboplatin and paclitaxel, which is commonly used for lung cancer, not advanced melanoma. As with many paraneoplastic syndromes, successful treatment of the underlying disease was associated with a rapid resolution of the symptoms.