Lymphangitic Carcinomatosis

1) The differential for a diffuse reticular interstitial pattern on CXR includes: pulmonary edema/fluid overload, atypical pneumonia (viral, PCP, mycoplasma), drugs (MTX, amiodarone, nitrofurantoin), UIP (IPF, RA, systemic sclerosis, dermatomyositis) and of course lymphangitic carcinomatosis.

2) Pulmonary lymphangitic carcinomatosis is a metastatic lung disease that occurs when tumors undergo hematogenous seeding with subsequent lymphatic involvement. It is most often secondary to adenocarcinomas: breast cancer (most common), lung cancer (bronchogenic adenocarcinoma), colon cancer, stomach cancer, prostate cancer, and cervical cancer. Also thyroid, pancreatitic, and laryngeal cancer.