Pulmonary Lymphangioleiomyomatosis and Micronodular Pneumocyte Hyperplasia associated with Tuberous Sclerosis: A Case Report

ABSTRACT

Lymphangioleiomyomatosis (LAM) is characterized by a hamartomatous proliferation of smooth muscle cells in the lung, mediastium, and abdomen. In the lung, an abnormal proliferation of smooth muscle is seen along the airways, blood vessels, and lymphatics, resulting in honeycombing of the lung. It occurs in 0.1-1% of tuberous sclerosis (TSC) patients. Micronodular pneumocyte hyperplasia (MNPH) is a rare but distinctive pulmonary manifestation of TSC, and appears to be a hamartomatous proliferation of the type II pneumocytes. We report a case of pulmonary LAM and MNPH associated with TSC and bilateral renal angiomyolipoma in a 26-year-old woman. Immunohistochemically, the spindle cells of LAM were positive for HMB-45, but the type II pneumocytes of MNPH were negative.