From the Guidelines
Minute pulmonary meningiothelial-like nodules (MPMNs) typically require no specific treatment as they are benign, incidental findings that rarely cause symptoms. The management approach consists primarily of conservative observation with periodic imaging follow-up, usually annual or biennial CT scans, to monitor for any changes in size or number, as suggested by the guidelines for incidentally detected indeterminate pulmonary nodules 1. No medications, surgical interventions, or other treatments are generally necessary for these lesions. If the nodules are discovered during evaluation for other conditions, the focus should remain on addressing the primary clinical concern rather than the MPMNs themselves. In rare cases where MPMNs show unusual growth patterns or are associated with symptoms, further evaluation with additional imaging or possibly biopsy may be warranted. The benign nature of these lesions is supported by their histological characteristics, which resemble meningothelial cells but are thought to represent a reactive proliferation of pulmonary interstitial cells rather than true neoplasms. Most MPMNs remain stable over time and do not progress to malignancy, which justifies the conservative management approach, and this approach is in line with recommendations for managing incidental pulmonary nodules, which emphasize the importance of considering a patient's risk factors and preferences in management 1. Key considerations in the management of MPMNs include:
- The size and morphology of the lesions
- Risk factors for malignancy
- Suitability for curative treatment, as outlined in guidelines for evaluating individuals with pulmonary nodules 1. However, given the more recent and specific guidance on incidentally detected indeterminate pulmonary nodules 1, this takes precedence in informing the management approach for MPMNs.
From the Research
Management Approach for Minute Pulmonary Meningiothelial-like Nodules
The management approach for minute pulmonary meningiothelial-like nodules (MPMNs) is primarily focused on diagnosis and monitoring, as these lesions are typically benign.
- Diagnosis is often incidental, with MPMNs discovered during imaging studies for other conditions 2, 3, 4, 5, 6.
- Imaging characteristics, such as ground-glass attenuation on computed tomography (CT) scans, can help identify MPMNs 2, 3, 6.
- However, MPMNs can be difficult to differentiate from malignant lesions, such as lung adenocarcinoma, due to similar CT findings 3.
- Definitive diagnosis often requires bronchial or percutaneous lung biopsy 5.
- Once diagnosed, the management approach for MPMNs typically involves monitoring, as these lesions are usually asymptomatic and benign 4, 5.
- In some cases, MPMNs may be associated with specific conditions, such as thromboembolism, cardiac disease, or malignancy, which may require additional management 2.
Clinical Considerations
- Clinicians should be aware of the imaging characteristics of MPMNs to guide appropriate management of lung diseases 6.
- MPMNs can present with a variety of imaging findings, including ground-glass nodules, part-solid nodules, and diffuse micronodules 2, 3, 4.
- The clinical course of MPMNs can be variable, with some cases remaining stable over time and others showing changes on follow-up imaging 3, 4.