Pleural effusion in an immunocompetent woman caused by Mycobacterium fortuitum

Mycobacterium fortuitum is a non-tuberculous mycobacterium that can cause pneumonia, abscess and empyema in subjects with predisposing lung diseases. However, pleurisy with effusion is rare. Herein, we report the case of a 74-year-old immunocompetent female patient without apparent risk factors, who suffered haemorrhagic pleural effusion as the main clinical manifestation. Pleural nodules were detected by computed tomography scan, and microbiological analysis revealed M. fortuitum in the absence of other pathogens. The patient was treated with ceftriaxone and ciprofloxacin, and full recovery ensued in 4 weeks. To our knowledge, this is the first reported case of haemorrhagic pleural effusion in an immunocompetent patient without underlying diseases. Although non-tuberculous mycobacterial infections are rarely accompanied by pleural involvement, M. fortuitum should be considered in such cases, especially when microbiology fails to detect the usual pathogens, and when the clinical picture is unclear.