A Mycobacterium malmoense infection of the hand presenting as carpal tunnel syndrome

We report an atypical tuberculous infection by Mycobacterium Malmoense of the synovium of the flexor tendons at the wrist presenting as carpal tunnel syndrome. This is the first time this organism has been described in a site other than the lungs or the cervical lymph nodes. Skeletal and articular tuberculosis usually result from reactivation of the original haematogenous seeding. Tuberculous tenosynovitis, although rare, presumably arises in a similar manner. The wrist and hand tendons are the commonest sites involved, and account for between 0.7 % and 5 % of all diagnosed synovial lesions (Feldman et al., 1971; Hodgson and Smith, 1972). The infection often presents in this region as a compound palmar ganglion with an associated carpal tunnel syndrome (Pimm and Waugh, 1957). In developed countries the incidence of infection caused by Mycobacterium tuberculosis has decreased, while that caused by opportunistic mycobacteria has become more common (Lancet, 1981; Grange and Yates, 1986). However, infections of the hand caused by these atypical mycobacteria are uncommon. Of those reported, M. marinum has been the most frequent agen