The Exception Proves the Rule: First Case of Tuberous Sclerosis-Related Pulmonary Lymphangioleiomyomatosis (LAM) in a Male Adolescent

Introduction

Pulmonary Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease which can occur sporadically (S-LAM) or in association with tuberous sclerosis (TSC-LAM). It Is estimated that 3.4–7.8 per million women are affected worldwide (O’Mahony et al., Breathe (Sheff). 2020;16(2):2007–2020). LAM typically presents with diffusely distributed cysts of 2mm-2cm diameter in the lung parenchyma caused by infiltration and proliferation of abnormal smooth muscle-like LAM cells (McCarthy et al., Lancet Respir Med. 2021;9(11):1313–1327). 70% of cases initially present with secondary pneumothorax. Further symptoms and clinical course vary broadly, ranging from asymptomatic patients to end stage lung disease necessitating lung transplantation (O’Mahony et al., Breathe (Sheff). 2020; 16(2): 2007–2020).

TSC-LAM, found almost exclusively in women of reproductive age, is caused by pathogenic variants in TSC1 or TSC2. Reports of TSC-LAM in men are controversial, due to absence of typical histopathology and/or pathogenic TSC variant. (McCarthy et al., Lancet Respir Med. 2021; 9(11): 1313–1327). To our knowledge, genetically confirmed TSC-LAM has never been described in the male pediatric population. Herein we report the first case of LAM in a male adolescent with confirmed pathogenic TSC1 variant.

Publication History

Article published online:
19 January 2023