Invasive cutaneous angiomatosis and thrombocytopenia in a cat

A 9-year-old 6.9-kg (15.18-lb) castrated male Siamese cat was evaluated because of a 3-year history of repeated hemorrhage from the right metacarpal pad.

Physical examination findings were unremarkable except for a 2-mm-diameter erosion of the right metacarpal pad. A CBC revealed marked thrombocytopenia. Serum biochemical analyses, retroviral screening, thoracic radiography, and abdominal ultrasonography revealed no abnormalities. Via ultrasonographic examination, the vasculature in the right metacarpal pad appeared increased, compared with that of the left pad; an aberrant arterial plexus that was confined to the metacarpal pad was identified via arterial angiography.

Surgical resection of the metacarpal pad (without digital pad transposition) with primary closure was performed. Histologic evaluation of the pad tissue revealed invasive cutaneous angiomatosis. The incision healed without complications, and limb function was considered normal. Administration of prednisone (2 mg/kg [0.91 mg/lb], PO, q 24 h) was initiated 4 weeks prior to surgery to treat suspected immune-mediated thrombocytopenia and continued afterwards with a tapering dosage. Platelet count was within reference limits 4 months after surgery; at 12 months, there was no evidence of recurrence of abnormal vasculature in the right metacarpal pad region.

Complete resection of the metacarpal pad (without pad transposition) resulted in successful and well-tolerated treatment of cutaneous angiomatosis of the metacarpal pad of a cat. Recurrence of abnormal vasculature was not evident at a 12-month follow-up examination. Thrombocytopenia is commonly associated with vascular anomalies in humans and may have been a contributing factor in this cat.