Coexistence of May Thurner syndrome and paroxysmal nocturnal hemoglobinuria: a case report

Coexistencia de síndrome de May-Thurner y hemoglobinuria paroxística nocturna: a propósito de un caso

Introduction: Deep vein thrombosis (DVT) causes high morbidity and mortality in young patients. Among the causes, May Thurner syndrome, an anatomical malformation that compresses the left iliac vein, and paroxysmal nocturnal hemoglobinuria (PNH), a rare hematologic disease associated with thrombosis and cytopenias, may explain cases of DVT. Clinical case: A 22-year-old female patient consulted for pain and edema of the left lower limb. Extensive DVT and an image suggestive of May Thurner syndrome was documented. Thrombectomy and stent implantation were performed, with favorable initial evolution. During follow-up, she presented thrombotic recurrence, hemolytic anemia and thrombocytopenia. Studies ruled out hereditary thrombophilia and confirmed PNH by flow cytometry. Eculizumab was started with clinical improvement. Discussion: The coexistence of May Thurner syndrome and PNH has not been previously reported. Both conditions predispose to thrombotic events, but with different pathophysiological mechanisms. Conclusion: This case highlights the importance of broadening the etiologic workup for unprovoked thrombotic events, especially in young patients with abnormal hematologic findings. Identification and specific treatment, such as the use of eculizumab in PNH, are key to improve prognosis.