[A clinicopathological analysis of pulmonary lymphangioleiomyomatosis]

Pulmonary lymphangioleiomyomatosis (PLAM) is a rare tumor with unique clinicopathological features. The aim of this study is to investigate the clinicopathological features, the diagnosis and differential diagnosis of pulmonary lymphangioleiomyomatosis.

Three cases of PLAM were analyzed by light microscopy, immunohistochemistry and their clinical data, and the relative literatures were reviewed.

Three cases of patients suffered from PLAM were the women in their reproductive aged, from 27 years to 45 years (mean 37.7 years), two cases of the HRCT showed bilateral diffuse cystic airspaces changed, and one case was the pneumothorax. The histopathological examination revealed the tumor was composed of the variably sized cystic spaces are lined by plaque-like or nodular aggregates of endothelial cells and the hyperplasia, smooth-muscle-like spindle cells which was along with the bronchi and the vessels. The immunohistochemistry showed that Des, Caldes, SMA, MSA, HMB-45, CD63, Vim, ER and PR were positive in the hyperplasia spindle cells, and there was no expression of MRAT-1. The FVIII, CD34 were positive in the capillary endothelial cells, and the D2-40 was positive in the lymphatic vessels. All the patients were alive without the recrudescence of the PLAM since the diagnosis, about 3 months to 25 months, and there was no LAM in their other systems.

The most significant histopathological feature of pulmonary lymphangioleiomyomatosis was the progressive invasion of smooth muscle cells into the lymphatic vessels, and the blood vessels. The majority of the cases occur in the lungs of the women in the predominantly premenopausal and middle-age. It is a poor prognosis due to the progressive respiratory failure.