Diffuse Pulmonary Meningotheliomatosis Presenting with the Cheerios Sign Diagnosed by a Transbronchial Lung Cryobiopsy: A Case Report

The "Cheerios sign" is a ring-shaped pulmonary nodule with central lucency, as observed on chest computed tomography. A 48-year-old woman with Turner syndrome presented with diffuse pulmonary nodules exhibiting the Cheerios sign. Although transbronchial lung biopsy is non-diagnostic, transbronchial lung cryobiopsy (TBLC) revealed nodules composed of meningothelial-like cells that were positive for epithelial membrane antigen, progesterone receptor, and CD56, thus leading to a diagnosis of diffuse pulmonary meningotheliomatosis. Estrogen and progesterone hormone therapy were discontinued, and the disease remained stable without treatment. This case highlights the diagnostic utility of TBLC for the evaluation of small pulmonary nodules that exhibit the Cheerios sign.