Incidentally Diagnosed Pulmonary Embolism Two Months After Living Liver Donation in a Donor With Homozygous MTHFR A1298C Mutation: A Case Report.

Living donor liver transplantation (LDLT) is widely performed in countries with limited cadaveric organ donation. Although donor hepatectomy is generally safe, venous thromboembolic events such as pulmonary embolism (PE) remain rare but potentially life-threatening complications. Genetic thrombophilia, including methylenetetrahydrofolate reductase (MTHFR) mutations, may contribute to thrombotic risk. A 39-year-old female living liver donor underwent right donor hepatectomy for LDLT. The donor had no preoperative risk factors for venous thromboembolism, and a routine thrombophilia panel, including protein C, protein S, antithrombin III, factor V Leiden, and prothrombin gene mutations, was normal. Two months after surgery, an abdominal computed tomography (CT) scan performed due to fluid collection adjacent to the remnant liver in ultrasound (USG) during routine follow-up incidentally revealed partial PE. Pulmonary CT angiography confirmed the finding, while lower extremity Doppler USG showed no evidence of deep vein thrombosis. Laboratory tests revealed elevated D-dimer and homocysteine levels. Further genetic evaluation demonstrated a homozygous MTHFR A1298C mutation. The patient was treated with low molecular weight heparin followed by oral anticoagulant therapy for 6 months, resulting in complete radiological resolution of the embolism. PE after donor hepatectomy is rare but potentially fatal. This case suggests that MTHFR A1298C mutation may represent a previously underrecognized risk factor for venous thromboembolism in living liver donors. In populations with a high prevalence of MTHFR mutations, extended thrombophilia screening and appropriate thromboprophylaxis may help reduce the risk of postoperative thromboembolic complications.