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

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).