Wrist tuberculosis in cladribine--induced remission of hairy cell leukosis

A 45-year-old man with "hand-shoulder" syndrome developing eight-months after Cladribine-induced remission of an 11-year-old hairy cell leukosis is presented. Wrist bone biopsy was performed because of failure of the algodystrophy treatment and radiographic findings of progressive osteoporosis. Caseating epiteloid granulomas abundant in Langhans cells were found histologically and later Mycobacterium tuberculosis species was isolated in culture specimen. Fistulas were formed that healed after a prolonged anti-tuberculosis therapy. The role of cellular immunity deficiency in Cladribine-treated hairy cell leukosis that predisposes to mycobacterial infection is discussed.