A recent study examined pulmonary involvement in chronic nonbacterial osteomyelitis, a rare condition associated with granulomatous inflammation and nodular lesions in the lungs.
In the study, published in ACR Open Rheumatology, researchers from multiple German centers participating in the Kerndokumentation Deutsches Rheumaforschungszentrum analyzed 22 patients with pulmonary chronic nonbacterial osteomyelitis (pCNO) and found favorable long-term outcomes, with complete remission reported in 60% of cases and partial remission in 20%.
The researchers investigated clinical presentations, imaging findings, and treatment responses. Pulmonary involvement in chronic nonbacterial osteomyelitis is usually asymptomatic and not associated with systemic inflammatory markers or additional organ complications.
The researchers found that pCNO was more prevalent among female patients (91% vs 62.8%, P = .006) and those with multifocal bone lesions (95% vs 65%, P < .001). Forty-two pulmonary lesions were identified, with patients having a median of two lesions each (range = 2–6). Lesion sizes ranged from 0.3 cm to 4.0 cm, with a median size of 1.8 cm. Consolidations or nodules abutting the pleura were common, occurring in 50% of cases.
Despite the presence of pulmonary lesions, systemic inflammation markers were not elevated, and no associations were found with additional organ involvement. Histologic examination, conducted in three patients, revealed granulomatous inflammation with lymphocyte infiltration. Prominent hilar lymph nodes were observed in 19% of cases, though none exhibited pathologic enlargement greater than 1 cm.
"pCNO is usually asymptomatic. Although more common in [female patients] and patients with multifocal CNO, pCNO is not associated with systemic parameters of inflammation or specific organ involvement," emphasized lead study author Toni Hospach, of Olgahospital at Klinikum Stuttgart in Germany, and colleagues.
The findings underscored the importance of distinguishing pCNO from malignancies or infectious diseases during differential diagnosis, as its asymptomatic nature and favorable resolution outcomes suggested that aggressive interventions may often be unnecessary.
Th study added to the limited body of knowledge on pulmonary manifestations in CNO and highlighted the need for further research to better understand the underlying mechanisms of lesion formation and progression.
Full disclosures are detailed in the study.