Sporadic lymphangioleiomyomatosis in a 33-year-old female with no association with tuberous sclerosis complex: Case report and a brief literature review

Lymphangioleiomyomatosis (LAM) is an uncommon, low-grade neoplastic cystic lung illness that mostly affects women of reproductive age and may manifest randomly or in conjunction with tuberous sclerosis complex (TSC). This case details a 33-year-old nonsmoker female who had two previous spontaneous pneumothoraces without clinical signs of TSC, as well as an 18-month history of worsening exertional dyspnea and a nonproductive cough that were first treated as asthma. Spirometry showed a mild obstructive pattern and decreased diffusing capacity, whereas high-resolution computed CT showed widespread thin-walled lung cysts with undamaged intervening parenchyma. A diagnosis of sporadic LAM was supported by a significantly elevated serum vascular endothelial growth factor-D (VEGF-D) level (1,200 pg/mL). A transbronchial biopsy showed bland spindle cells that were positive for melan-A, HMB-45, and smooth muscle actin, consistent with perivascular epithelioid cells (LAM cells) origin. Sporadic illness was confirmed by next-generation sequencing, which found a somatic TSC2 frameshift mutation without germline change.

In addition to immunization and pneumothorax precautions, the patient was given sirolimus and inhaled tiotropium. She had very mild side effects during the 18-month follow-up, including increased exercise tolerance, a stable cystic load, improved FEV1, and lowered VEGF-D levels. This case demonstrates the effectiveness of mTOR inhibition in halting disease progression and underscores the utility of a noninvasive, biomarker- and imaging-based diagnostic strategy for sporadic LAM.