Mycobacterium Immunogenum Flexor Tenosynovitis: A Case Report

Background Nontuberculous mycobacterial (NTM) flexor tenosynovitis represents a rare but potentially devastating manifestation of upper extremity infection. We present a novel case of NTM flexor tenosynovitis in whichMycobacter iumimmunogenumwas found to be the causative agent. Case Description The patient presented with pain and insidiously progressive swelling and required multiple operative interventions and a complex antimicrobial regimen based on susceptibility profiles. Specifically, our patient was managed with three debridements and empiric antimicrobial agents based on inherent macrolide sensitivity, with later conversion to a complex antimicrobial regimen tailored to sensitivity. Literature Review The diagnosis and management of NTM tenosynovitis arechallenging because of low suspicion, nonspecific presentation, and cumbersome laboratory identification techniques.M. immunogenumwas only characterized in the past two decades, and, to our knowledge, this is the first reported case of the pathogen causing a musculoskeletal infection. Clinical Relevance We present this case primarily because of the novelty of the organism and to demonstrate the recalcitrant nature of the infection. Due to the extensive resistant patterns of M. immunogenum, management requires complex antimicrobial preparations and almost certainly needs multispecialty collaboration between orthopaedic surgery and infectious diseases.