Archived case 181 · July 30-August 6, 2015
65 y/o female with chronic nonproductive cough
How would you characterize the lung abnormalities (morphology, distribution, etc.)? What is your top 3 differential diagnosis?
Axial and coronal CT images of the chest are provided and demonstrate wide spread groundglass nodules randomly distributed throughout both lungs, most measuring less than 1 cm. No lobes are spared and there is no specific predilection for the upper or lower lung zones. Answer Diagnosis: Diffuse Pulmonary Meningotheliomatosis
Diffuse Pulmonary Meningotheliomatosis
Answer
Diagnosis: Diffuse Pulmonary Meningotheliomatosis
Differential Diagnosis
• Acute hypersensitivity pneumonitis • Vasculitis • Atypical infection • Metastatic disease• Smoking related lung injury
Explanation
Pulmonary meningothelial -like nodules (MLNs) are rare lesions made up of small epitheloid cell clusters and are located in the parenchyma of the lungs. The patient population shows a marked female predominance of approximately 2.3:1. Symptoms are most common in the 6 th and 7 th decades, often dry cough. Although they usually appear as solitary nodules, multiple lesions with unilateral involvement have also been defined. Diffuse bilateral meningothelial nodules are extremely rare but could be considered in cases where any obvious cause is unclear.
First described in 1960, the etiology remains unclear, although histological features resemble meningiomas . Imaging features are typically small (1-4 mm) groundglass or micronodules randomly distributed throughout the lungs. Of note, this process has been associated with both smoking and the presence of pulmonary embolism. Tissue sampling via VATS can provide a definitive diagnosis.
1. Suster S, Moran CA. Diffuse pulmonary meningotheliomatosis . Am J Surg Pathol 2007;31:624-31. 2. Mukhopadhyay S, El- Zammar OA, Katzenstein AA. Pulmonary meningothelial -like nodules. New insights into a common but poorly understood entity. Am J Surg Pathol 2009;33:487-95. 3. Nazan SEN, et al. A rarely seen parenchymal lung disease: diffuse pulmonary meningotheliomatosis . Tuberk Toraks 2015;63(1):37-41
(Click for a larger image.)
Original case written by its authors at Virginia Commonwealth University and published at this address as part of a weekly teaching collection. Reproduced here as an archive.