Achalasia Treatment Alone Clears Rare Mycobacterial Lung Infection in a World First

In a result that has startled pulmonologists and gastroenterologists alike, Japanese clinicians have documented the first known case of a pulmonary nontuberculous mycobacterial infection that resolved completely without a single dose of antimycobacterial drug therapy. The infection, caused by the rapidly growing environmental bacterium Mycobacterium fortuitum, had smouldered in the left lower lobe of a 50-year-old man’s lung for more than two years. What ultimately cured it was not an antibiotic regimen but a endoscopic procedure designed to treat a completely different organ: his oesophagus. The case, published in Respirology Case Reports, suggests that in a specific subset of patients, the true driver of a stubborn lung infection may not be the microbe itself but the mechanical failure of the food pipe that keeps feeding it.

The story began in March 2022, when the previously healthy man developed fever and a dry cough. Empirical antibiotics for suspected pneumonia achieved nothing. By April he had been admitted to hospital, where computed tomography revealed consolidation studded with ground-glass opacities in his left lower lobe. His blood work painted a picture of vigorous inflammation: a white cell count of 17,600 per microlitre with neutrophils dominating, and a C-reactive protein level of 15.0 milligrams per decilitre. Crucially, he carried a long-standing diagnosis of oesophageal achalasia, a rare motility disorder first treated with balloon dilation at age 35. Over the preceding five years his ability to swallow had deteriorated relentlessly, with worsening dysphagia and vomiting despite medical therapy.

Diagnostic certainty proved elusive. A single sputum culture yielded Mycobacterium fortuitum, but subsequent cultures were negative, and the findings did not satisfy standard criteria for established nontuberculous mycobacterial disease. The team initially diagnosed aspiration pneumonia complicated by secondary organising pneumonia, treating him with antibiotics and corticosteroids. Neither touched the disease. Then came an observation that would eventually unlock the diagnosis: his respiratory symptoms rose and fell in eerie synchrony with his gastrointestinal ones, flaring during bouts of vomiting and easing when the vomiting subsided. That temporal coupling, the clinicians reasoned, pointed toward chronic microaspiration as the engine of the lung disease.

When symptoms escalated again in April 2024, bronchoscopy was repeated. Histopathological examination of biopsy specimens from the left lower lobe revealed non-caseating granulomas, the characteristic immune structures of mycobacterial infection, and Ziehl-Neelsen staining demonstrated acid-fast bacilli directly within the tissue. Combined with the earlier positive culture, these findings fulfilled the current Japanese diagnostic criteria for pulmonary nontuberculous mycobacterial disease attributable to M. fortuitum driven by chronic aspiration secondary to achalasia. The authors acknowledge that a two-year gap separated the microbiological and histopathological evidence, but they argue that persistent symptoms, repeated parallel exacerbations, and tissue demonstrating granulomas with acid-fast organisms made transient colonisation or contamination implausible.

The therapeutic decision was the radical part. Recognising that control of the underlying oesophageal disorder was essential, the team performed peroral endoscopic myotomy, known as POEM, in October 2024. POEM is a minimally invasive procedure in which an endoscope tunnels through the oesophageal wall to divide the muscular fibres of the lower oesophageal sphincter, restoring the passage of food into the stomach. The effect on the patient’s achalasia was dramatic; his swallowing difficulties and vomiting improved markedly. But the lung outcome was the real headline. Without ever initiating antimycobacterial therapy, his cough and fever resolved, and follow-up imaging showed marked radiological improvement. More than a year after the procedure, no recurrence of pneumonia or mycobacterial disease had been observed, though mild residual fibrosis remains.

To appreciate why this matters, one must understand both organisms and mechanism. Mycobacterium fortuitum belongs to Runyon group IV, the rapidly growing nontuberculous mycobacteria, and is ubiquitous in soil and water. It most often causes skin, soft-tissue, catheter-related and postoperative infections, with pulmonary disease being distinctly uncommon and usually a secondary affair in people with structural lung disease or chronic aspiration. Achalasia, characterised by impaired relaxation of the lower oesophageal sphincter and absent peristalsis, produces stasis of food within a dilating oesophagus. Nontuberculous mycobacteria are commonly ingested with food and can colonise the upper gastrointestinal tract; in achalasia patients, repeated microaspiration of these retained contents seeds the airways. The association between achalasia and pulmonary nontuberculous mycobacterial infection has been recognised for decades, with rapidly growing species frequently implicated.

The authors add a provocative mechanistic twist: the lipid-rich environment within retained oesophageal contents may itself potentiate the pathogenicity of rapidly growing mycobacteria. Previous work has suggested that lipid conditions can impair macrophage phagocytosis and promote mycobacterial growth, effectively disarming one of the lung’s first lines of cellular defence. In this patient, the team notes that dietary habits favouring high-fat intake may have facilitated bacterial persistence, though they concede this remains speculative. If confirmed, the idea would give clinicians yet another reason to view oesophageal stasis not as a mere inconvenience but as an active contributor to pulmonary immunopathology.

How does this case compare with the medical literature? The authors compiled eleven previously reported cases of pulmonary nontuberculous mycobacterial infection associated with achalasia, spanning organisms from M. fortuitum and M. abscessus to M. thermoresistibile and M. wolinskyi. Virtually every patient required prolonged multidrug antimycobacterial regimens, often involving combinations of amikacin, imipenem, clarithromycin, fluoroquinolones, linezolid or other agents, in addition to endoscopic or surgical correction of the oesophagus. In contrast, the present patient achieved sustained clinical and radiological improvement through POEM alone. To the authors’ knowledge, this is the first reported case in which treating achalasia alone successfully controlled an established pulmonary nontuberculous mycobacterial infection, implying that eliminating chronic aspiration can restore effective host defence mechanisms capable of containing the infection without pharmacological help.

The authors are appropriately cautious about the limits of a single observational report. Causality cannot be definitively established: spontaneous fluctuation of disease activity or delayed effects of earlier treatments cannot be entirely excluded, though the tight temporal relationship between POEM and sustained improvement supports the aspiration hypothesis. A further limitation is the absence of microbiological follow-up, because once his respiratory symptoms resolved the patient could no longer produce sputum, so eradication of the organism could not be confirmed in cultures. Still, the clinical message is unambiguous. Clinicians should consider oesophageal achalasia as an underlying cause of pulmonary nontuberculous mycobacterial infection, particularly when respiratory symptoms fluctuate in step with gastrointestinal ones. In such patients, addressing the underlying motility disorder may be as important as any antibiotic, and in rare cases may be enough on its own to conquer the infection and prevent recurrence.

Subject of Research: A case report of pulmonary Mycobacterium fortuitum infection associated with oesophageal achalasia that improved after peroral endoscopic myotomy without antimycobacterial therapy.

Article Title: Pulmonary Mycobacterium fortuitum Infection Associated With Achalasia Treated With Peroral Endoscopic Myotomy Alone: A Case Report

Article References: Masuda, H., Torii, R., Yamasaki, K., Shingu, T., Hata, R., & Yatera, K. (2026). Pulmonary Mycobacterium fortuitum Infection Associated With Achalasia Treated With Peroral Endoscopic Myotomy Alone: A Case Report. Respirology Case Reports, 14(9), Article e70718. https://doi.org/10.1002/rcr2.70718

Image Credits: AI Generated

DOI: 10.1002/rcr2.70718

Keywords: Mycobacterium fortuitum, nontuberculous mycobacteria, achalasia, peroral endoscopic myotomy, chronic aspiration, pulmonary infection, POEM, respirology, case report, oesophageal motility disorder, Pulmonary, Mycobacterium