Pulmonary lymphangitis carcinomatosis: systematic review and meta-analysis of case reports, 1970-2018

Pulmonary lymphangitis carcinomatosis (PLC) is a life-threating complication in patients suffering from malignancies. Misleading and nonspecific symptoms often result in a delayed diagnosis. This review was aimed at evaluating epidemiology, clinical manifestations, and survival of patients with PLC reported in the literature. According to our knowledge, this study is the first such extensive analysis of PLC. We searched for the literature in the PubMed database for articles published from 1970 to 2018 using keywords: lung, pulmonary, lymphangitic, carcinoma, carcinomatosis. Pulmonary lymphangitis carcinomatosis rarely occurs, thus all data were extracted from case reports and case series consisted of a method for identifying individual-level patient data. In the final analysis, 108 articles (139 individual patient cases) were included. The mean age of PLC occurrence is 49.21 years. There is no difference in the prevalence between men and women. The most common underlying primary tumors coexisting with PLC are breast (17.3%), lung (10.8%), and gastric cancers (10.8%). Dyspnea and dry cough were the most common symptoms occurring in 59.0% and 33.8% of patients, respectively. In half the patients, PLC developed in fewer than ten months after first diagnosis of cancer. Pulmonary lymphangitis carcinomatosis diagnosis is associated with a poor prognosis: approximately half of patients die within two months of their first respiratory symptoms and three weeks from admission to hospital. Regarding survival time, we observed better results achieved in patients described between 2000 and 2018 compared to 1970 through 1999. In the presence of progressive dyspnea, cough, and lesions comparable to interstitial lung disease, diagnosis of PLC should be considered. Pulmonary lymphangitis carcinomatosis can be the first manifestation of primary occult neoplasm and may occur at any age. Adenocarcinoma, especially primary lung, breast, and gastric cancers is the most common cancer coexisting with PLC.