Multiple basal cell carcinomas associated with hairy cell leukaemia

We report the case of a caucasian woman who, between the ages of 49 and 51 years, developed multiple (> 20) basal cell carcinomas (BCC). There was no family history of BCC. No abnormalities in the human homologue of the Droso phila segment polarity gene patched (PTCH), glutathione S-transferases T1 a nd M1, or cytochrome P450 1A1 were detected by polymerase chain reaction (P CR)-based molecular analysis. There was, however, actinic damage of the ski n in sun-exposed areas. The patient was diagnosed as having hairy cell leuk aemia (HCL) at the age of 51 years, based upon leucocyte morphology as asse ssed by light and electron microscopy, tartrate-resistant acid leucocyte ph osphatase (TRAP) staining, fluorescence activated cell scanning of peripher al blood leucocytes and bone marrow histology. As the leukaemia slowly prog ressed over a 3-month period, the patient developed four further BCCs. Give n that HCL is characterized by a profound defect in T-cell function, it is conceivable that T-cell immune dysregulation can contribute to the pathogen esis of BCC, possibly enhancing the aetiological effect of ultraviolet irra diation.