Letter to the Editor: Multiple Abscesses Caused by Mycobacterium abscessus Infection

To the Editor:

Nontuberculous mycobacteria (NTM) is a general term for a large group of mycobacteria except Mycobacterium tuberculosis (MTB) and Mycobacterium leprae. It is an opportunistic pathogen that exists widely in nature and manmade environments, and is mainly associated with soil, water sources, and biofilms. ¹ Mycobacterium abscessus, a type of NTM, is fast-growing, multi-drug–resistant, and most commonly infects the lungs, and can also infect the skin, soft tissues, bones, central nervous system, eyes, and immunocompromised patients.^2,3 The clinical manifestations and imaging features of NTM-infected patients are not typical, leading to misdiagnosis of MTB infection. We report a case of multiple abscesses caused by Mycobacterium abscessus infection that was initially misdiagnosed as tuberculosis.

A 54-year-old male was transferred to our hospital with lower back pain, fever, and weight loss for more than three months. He was initially considered to have spinal tuberculosis with cold abscess formation and was treated with isoniazid, rifampicin, pyrazinamide, and ethambutol for antituberculosis, but his condition worsened. His nutritional status was poor, with a body mass index of 15.6 kg/m². His hemoglobin was 65 g/L, alanine transferase was 72 U/L, aspartate aminotransferase was 133.9 U/L, and albumin was 22.9 g/L. Magnetic resonance imaging showed bone destruction of multiple vertebral bodies in the spine, narrowing of the intervertebral space, and multiple abscess formation in the lower back, spinal tuberculosis with cold abscess formation was suspected (Fig 1A and 1B).

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FIG. 1.

A and B: Magnetic resonance imaging showed bone destruction of multiple vertebral bodies in the spine, narrowing of the intervertebral space, and multiple abscess formation in the lower back.

The patient underwent abscess drainage and the pus was positive for acid-fast staining but negative for MTB nucleic acid. Nontuberculous mycobacteria infection was suspected. Mycobacterium abscessus was identified by pus culture and microbial mass spectrometry. According to the drug susceptibility results, an anti-infective regimen was re-formulated for the patient (amikacin, clarithromycin, rifapentine, and moxifloxacin), but the patient could not tolerate the adverse drug reactions and stopped treatment.

Mycobacterium abscessus infection is relatively rare, and is often misdiagnosed as MTB infection; the diagnosis depends on bacterial culture and identification. Early diagnosis and early treatment are important for the prognosis of patients.