A40-37 Lymphangioleiomyomatosis in Pregnancy With Massive Bilateral Renal Angiomyolipomas Complicated by Post-Embolization Hypoxemia and Recurrent Pneumothorax

Abstract Introduction Lymphangioleiomyomatosis (LAM) is a rare progressive multisystem disease predominantly affecting premenopausal women and characterized by cystic lung disease with extrapulmonary involvement, most commonly renal Angiomyolipomas (AMLs). LAM occurs in two forms: sporadic LAM, which arises in otherwise healthy women, and TSC-associated LAM, which occurs in patients with tuberous sclerosis complex. Diagnosis is typically based on characteristic CT findings of diffuse, thin-walled pulmonary cysts and is supported by extrapulmonary manifestations such as renal AMLs or elevated serum VEGF-D levels. Management focuses on supportive care, use of sirolimus to slow pulmonary decline, and prevention or treatment of complications. Case Description A 30-year-old gravida 2 para 1 was noted to have a nontender right upper-quadrant mass during a routine 2nd trimester examination. Ultrasound revealed an ill-defined lesion with increased vascularity. MRI demonstrated multiple bilateral renal masses consistent with AMLs measuring 14.9 cm on the right and 8.8 cm on the left, with small areas of hemorrhage noted. At 30 weeks, the patient was electively admitted for prophylactic embolization of the right AML. Routine pre-procedure chest X-ray revealed a right pneumothorax managed with a chest tube. Subsequently, the patient underwent AML embolization that was complicated by suspected gelfoam migration to the pulmonary vasculature causing acute hypoxemia. Routine workup of hypoxia revealed diffuse, thin-walled pulmonary cysts consistent with sporadic LAM and distal pulmonary arterial filling defects (Figure 1). She was admitted to the ICU for hypoxic respiratory failure and subsequently had a precipitous spontaneous vaginal delivery at 31 weeks with favorable maternal and neonatal outcomes and improvement of hypoxia. Postpartum, she developed a recurrent right pneumothorax requiring reinsertion of a chest tube and ultimately underwent robotic right upper-lobe wedge resection with mechanical pleurodesis. The patient was discharged against medical advice several days later. Outpatient pulmonary follow-up was arranged for VEGF-D testing, pulmonary function tests, and evaluation for sirolimus therapy after wound healing. Case Discussion Patients with LAM are mostly premenopausal females, and in some, symptom onset and diagnosis occur during pregnancy, as seen in our patient. Pregnancy can exacerbate LAM, increasing the risk of recurrent pneumothorax and AML hemorrhage. Sirolimus therapy is generally avoided during pregnancy due to limited safety data and the risk of delayed wound healing, with initiation recommended postpartum. This case highlights the importance of individualized, multidisciplinary management of pregnant patients with LAM to ensure maternal and fetal safety while minimizing disease progression. This abstract is funded by: None