What disorders cause the linear pattern of interstitial disease?
Causes of the linear interstitial pattern include:
- • Interstitial pulmonary edema
- • Lymphangitic carcinomatosis
- • Sarcoidosis
Congestive heart failure and other causes of interstitial pulmonary edema are the most common causes of the linear pattern. In nearly all cases, the presence of a linear interstitial pattern should be assumed to represent interstitial pulmonary edema. Lymphangitic carcinomatosis is the most common chronic cause for the linear pattern. This is a form of hematogenous metastasis that grows along the interstitial framework of the lung, rather than growing concentrically as nodules. Breast and lung cancers are the malignancies most likely to cause a pattern of lymphangitic metastasis. Gastric, pancreatic, and ovarian carcinomas are other causes of lymphangitic carcinomatosis. Sarcoidosis typically causes peribronchial granulomas, which may also result in interstitial lung disease with a pattern of lines radiating from the hilum of the lung, producing a linear pattern.