Unexplained recurrent diffuse bleeding diathesis as a manifestation of nonaneurysmal intimomedial mucoid degeneration

Intimomedial mucoid degeneration (IMMD) is an exceptionally rare and potentially life-threatening vasculopathy characterized by mucoid accumulation within the intima and media, destruction of elastic fibers, and subsequent arterial wall weakening. Previously reported cases have been associated with aneurysmal disease, often accompanied by an increased risk of intraoperative hemorrhage.

Should IMMD be considered in patients with bleeding of unknown cause despite the absence of aneurysms?

We describe a patient with an isolated, recurrent, and unexplained severe diffuse bleeding diathesis in the absence of any detectable aneurysm. He ultimately died of multiorgan failure following profound hemorrhagic shock due to retroperitoneal bleeding. Postmortem histopathology revealed features consistent with IMMD despite the lack of aneurysmal changes.

This case highlights a broader clinical expression of IMMD than previously recognized by demonstrating that recurrent severe bleeding may occur in the absence of aneurysmal disease. It underscores the importance of further case reporting to improve future diagnosis and management.