Abstract
Diffuse pulmonary lymphangiomatosis (DPL) is a rare lymphatic disorder characterized by uncontrolled proliferation of lymphatic vessels. Histologically benign, however, it can lead to death because of its progression. In this paper, we would like to present an unusual case of diffuse pulmonary lymphangiomatosis involving a 28-year-old young female who was suffered chest pain and polypnea for one year, and also a lot of chylous effusion in left chest. Lymphoma and lymphangitic metastasis was the primary diagnosis in other hospitals. However, histologic sections of pleural biopsy revealed diffuse pleural lymphatic proliferation characteristic of DPL, wherein the histologic findings can be subtle and could be overlooked as nonspecific reactive changes or misdiagnosed as an idiopathic interstitial lung disease. Recognition of the characteristic lymphangitic distribution of abnormally dilated or reduplicated lymphatic spaces is the key to the correct diagnosis.