Diffuse cystic lung disease due to pulmonary metastasis of colorectal carcinoma.

The diffuse cystic lung diseases (DCLDs) are a pathophysiologically heterogeneous processes characterized by the presence of multiple thin-walled, air-filled spaces within the pulmonary parenchyma. The most common causes of DCLD are lymphangioleiomyomatosis (LAM) and pulmonary Langerhans cell histiocytosis (PLCH). DCLD develops rarely as a result of malignancy, typically secondary to metastases from peripheral sarcomas and mesenchymal tumors.