Pulmonary mesenchymal cystic hamartoma
Pulmonary mesenchymal cystic hamartomas (PMHCs) are a rare subtype of pulmonary hamartomas.
Pathology
They usually comprise multiple bilateral cysts and nodules. The cyst walls are lined with normal respiratory epithelium and the nodules are permeated by scattered airways that are also lined with normal respiratory epithelium. Occasionally, lesions may be single. The majority of the cases are benign but there are occasional cases of associated sarcomatous tumors .