Lymphangioleiomyomatosis: X-ray morphological comparisons

Abstract

Lymphangioleiomyomatosis (LAM) is a rare, slowly progressing disease characterized by a tumor-like overgrowth of smooth muscle fibers in the interstitial lung tissue, around blood and lymph vessels, bronchi, bronchioles, in lymph nodes. The disease has mainly been described in women of childbearing age, with a mean age of diagnosis of about 35 years.Methods. This retrospective, cohort study included 16 patients who were diagnosed with LAM at the age of 17 – 53 years (Me – 39, HQ – 42.5, LQ – 30.5). The calculation of the volumetric area of cystic lesion in the entire volume of the lungs was carried out using the GE aws 3.2 Thoracic VCAR software. To assess the area of cystic lesion on histological sections, we calculated area of cystic formations, in the walls of which smooth muscle nodules were found. For statistical analysis, the Kolmogorov–Smirnov test, the Mann – Whitney U-test (p < 0.05), and the Spearman correlation analysis were used.Results. Morphometric analysis of histological preparations of the lungs showed no statistically significant difference between women of young age and older age. A correlation was found between the volumetric area of cystic lesion on CT and FEV1 (correlation coefficient = –0.886). Baseline median area of cysts was larger in patients who later deteriorated, while condition of patients with a smaller area of cysts remained stable (2.677 vs 1.119 mm2  correspondingly).Conclusion. The volumetric area of cystic lesions in LAM correlates with functional parameters. The size of cysts in LAM may determine the prognosis of the course of the disease, because the formation of larger cysts is an unfavorable prognostic factor that increases the risk of developing pneumothorax.