[Skin necrosis in the front foot area during anticoagulation with phenprocoumon].

History And Admission Findings: A 52-year-old woman was admitted because of pain for several days in the lower left leg and increasing pretibial swelling with livid discoloration. Six months before she had undergone a bilateral adnexectomy with removal of the omentum and subsequent chemotherapy for ovarian cancer.

Investigations: Duplex sonography on the day of admission revealed thrombosis of the left popliteal vein with an unobstructed femoral vein. Both the quick value (89%) and partial thromboplastin time (PTT, 35.9 s) were within normal limits. Computed tomography and sonography were highly suspicious of a local recurrence of the ovarian cancer with peritoneal carcinomatosis.

Treatment And Course: PTT-effective heparinization (heparin-Na) was initiated together with overlapping anticoagulation with phenprocoumon (thromboplastin time 20-30%). On the 9th day after starting phenprocoumon painful, black necrotic changes began to appear on the skin of the left first to fourth toes. Assuming these to be due to phenprocoumon, anticoagulation was switched to low-molecular heparin (Enoxaparin), and antithrombin III and protein C were administered. A few days later thrombosis of the right iliac vein occurred, probably caused by local recurrence of the ovarian cancer. No palliative chemotherapy was undertaken in view of the thrombotic complications. The patient died a few months later from the cancer.

Conclusion: If there is an underlying malignancy, chemotherapy and therapeutic vitamin-K antagonism in the presence of thromboembolic complications increases the risk of lowering protein C activity and may cause the rare complication of skin necrosis, induced by phenprocoumon.