Mycobacterium scrofulaceum disease: experience from a tertiary medical centre and review of the literature.

Introduction: Mycobacterium scrofulaceum infection has been identified in cases of paediatric cervical lymphadenitis but is less well defined in adults. To further characterize manifestations of M. scrofulaceum disease and treatment approaches, we reviewed our medical centre's experience and other published reports. Methods: We performed a retrospective chart review of patients at our medical centre with a positive M. scrofulaceum culture over a 15-year period. We compare our findings with those published in the literature to identify commonalities in disease presentations and treatment outcomes. Results: We identified 17 patients in our centre with positive M. scrofulaceum cultures, 10 of whom were diagnosed with clinical infection. The types of disease encountered included pulmonary and pleural infection (4), bone and joint infections with a foreign body (2), skin and soft tissue infection (2), brain abscess (1) and paediatric cervical adenitis (1). Structural lung disease was a common finding in cases of pulmonary infection. All adult patients except those with bone and joint infections had some type of immunomodulatory condition and/or structural lung disease. In seven patients, M. scrofulaceum was isolated in urinary or respiratory cultures without signs of clinical disease. Conclusion: M. scrofulaceum is a rare cause of non-tuberculosis mycobacterial infection in humans but can infect any tissue. Adults with pulmonary disease often have underlying structural lung disease, and those with extrapulmonary disease commonly have immunosuppressive conditions or foreign body-associated infections. Treatment outcomes are generally favourable; however, in patients with pulmonary M. scrofulaceum disease prognosis is more guarded.