Digital necrosis as a paraneoplastic syndrome

We describe a 62-year-old woman who developed sudden onset of digital ulceration and necrosis with high titres of antinuclear antibodies and cutaneous vasculitis who was found to have small cell lung cancer. The combination of antinuclear antibodies, vasculitis, and digital ulceration has not been previously described in association with malignancy, although malignancy has been reported with each of these findings independently. The literature on digital necrosis as a paraneoplastic syndrome is reviewed and possible mechanisms discussed. This case is typical of the majority of those reported, in that the digital necrosis preceded the diagnosis of the malignancy, only the upper extremities were involved, the underlying malignancy was a carcinoma, and while treatment directed at the vasculitis was ineffective, there was rapid improvement of the digital lesions with treatment of the lung tumor. The most likely mechanism for these findings is a systemic vasculitis related to undefined tumor antigens. Unexplained digital necrosis should prompt a search for malignancy.