Overview
Introduction
Lymphangioleiomyomatosis (LAM) is an uncommon systemic, low grade neoplastic disease that affects almost exclusively adult women, with a reported prevalence of roughly five per...
Lymphangioleiomyomatosis (LAM) is an uncommon systemic, low-grade neoplastic disease that affects almost exclusively adult women, with a reported prevalence of roughly five per million. It may occur sporadically or with tuberous sclerosis complex (TSC). LAM cells arise after loss-of-function changes involving the TSC1/TSC2 tumour-suppressor pathway. Without normal TSC1/TSC2 inhibition, mechanistic target of rapamycin complex 1 (mTORC1) signalling remains active and promotes LAM-cell growth and migration. Those cells progressively infiltrate lung tissue and lymphatic channels. The resulting structural damage explains the clinical pattern: diffuse pulmonary cysts cause airflow obstruction and recurrent secondary pneumothoraces; lymphatic involvement causes chylous pleural effusions or ascites; and abdominal disease may include renal angiomyolipomas and lymphangioleiomyomas. The central clinical model is progressive structural injury, not an isolated airway disorder. A young or middle-aged woman with unexplained exertional dyspnoea, obstructive physiology, recurrent pneumothorax, chylous fluid, TSC, or a renal angiomyolipoma deserves a LAM-focused assessment.