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

A patient presented with isolated, recurrent, unexplained severe diffuse bleeding diathesis without any detectable aneurysm.

• The report is a single-patient case description.
• The bleeding was recurrent and severe, and its cause remained unknown during life.
• No aneurysm was detected, in contrast to previously reported IMMD cases.

The patient died of multiorgan failure after profound hemorrhagic shock caused by retroperitoneal bleeding.

• The terminal event was retroperitoneal hemorrhage leading to hemorrhagic shock.
• Death followed from multiorgan failure.

Postmortem histopathology showed features consistent with intimomedial mucoid degeneration despite the absence of aneurysmal changes.

• IMMD is characterized by mucoid accumulation within the intima and media, destruction of elastic fibers, and arterial wall weakening.
• The histopathological findings were described as 'consistent with IMMD' rather than as a definitive diagnosis.
• The diagnosis was made postmortem, not during life.

The case suggests IMMD can present clinically with recurrent severe bleeding in the absence of aneurysmal disease, which is a broader expression than previously recognized.

• Previously reported IMMD cases have been associated with aneurysmal disease, often with increased risk of intraoperative hemorrhage.
• The authors pose the question of whether IMMD should be considered in patients with bleeding of unknown cause even without aneurysms.

IMMD is described as an exceptionally rare and potentially life-threatening vasculopathy, and the authors call for further case reporting to improve diagnosis and management.

• The authors state that further case reporting is important for future diagnosis and management.
• The evidence base is a single case, so no estimates of frequency or risk are provided.