[Mononeuritis multiplex due to thrombotic ischemia of primary antiphospholipid antibody syndrome without vasculitis: an autopsy case report].

The patient was a 78-year-old man. Three years before admission, he developed transient peripheral neuropathy and purpura, and at admission, he presented with livedo reticularis of both his lower extremities and with mononeuritis multiplex. Vasculitis was not observed, and antiphospholipid antibodies were detected. The nerve and skin biopsies revealed no inflammation; axonal degeneration accompanied by thrombi was found in his arterioles and venules. Based on these findings, he was diagnosed with ischemic peripheral neuropathy due to primary antiphospholipid syndrome. Administration of anticoagulant therapy resulted in an improvement in symptoms; however, two months later, a relapse occurred, and the patient contracted an infection while undergoing immunosuppressive therapy. The infection became fulminant, and the patient succumbed to multiple organ failure. The autopsy revealed a systemic arterial and venous embolism; however, no vasculitis was observed. Antiphospholipid syndrome, which is responsive to antithrombotic treatment, should be considered as a differential diagnosis of mononeuritis multiplex.