Skin lesions in a patient with hairy cell leukaemia.

Accepted 10 May 1996 A 62-year-old woman was diagnosed as suffering from hairy cell leukaemia, on the basis of bone marrow biopsy results and a positive tartrate-resistant acid phosphatase stain. A single course of 2-chlorodeoxyadenosine was administered as a continuous intravenous infusion over seven days. During the following weeks her complete blood count reached almost normal values except for a lymphopenia of 0.51.0 x 109/1 which persisted during the following months and was attributed to the lympholytic effects of 2-chlorodeoxyadenosine. Bone marrow biopsy six months after treatment showed complete remission of the haematologic disease. Three months later the patient presented with two new erythaematous nodules, approximately 2 x 2 cm each, overlying the dorsal aspect of her right hand (figure 1). Otherwise the physical examination was normal. At that time the complete blood count was normal except for lymphopenia of 0.6 x 109/l with an abnormal CD4/CD8 ratio of less than 1.0. The absolute CD4+ count was 224/ul (normal range 3651600/,l) and absolute CD8+ count 275/,il (normal range 2702400/,il). Histology of the skin biopsies taken from both lesions is shown in figure 2. The immunohistochemical stain with a monoclonal anti-human hairy cell leukaemia antibody (clone DBA.44) was negative. Cultures were obtained from both lesions. While the microbiological test results were pending, the patient was treated for a week with clarithromycin for an incidental upper respiratory tract infection. A significant regression in the size of both skin lesions was noted.