gms | German Medical Science

Objectives/Interrogation: We report a very rare case of intraneural hemangioma of a digital nerve reconstructed using a collagen artificial nerve conduit after segmental nerve resection of hemangioma because complete excision was considered difficult without sacrificing the nerve fascicles, even with microsurgical technique.

Methods: A healthy 30-year-old right-handed male presented with a palpable mass on the radial side of his left index finger noticed a few years ago. His medical history was unremarkable with no previous trauma. The mass was red, bean-sized, mobile, and independent of the adjoining tendons. Although tenderness was positive, Tinel's sign was negative, and no sensory deficits were detected. An ultrasound examination revealed a well-defined, oval, hypoechoic subcutaneous lesion in continuity with the digital artery and digital nerve. Magnetic resonance imaging revealed a subcutaneous small lesion that was nonspecific hypointense on T1-weighted images and heterogeneous hyperintense internally. After administration of an intravenous contrast agent, the lesion showed no enhancement.

Results and Conclusions: Exploration revealed a dark blue tumor originating from the radial digital nerve. Because the tumor was strongly adhesive to fascicles, it could not be resected without sacrificing a nerve segment. The tumor with the involved part of the digital nerve was resected, and the 15-mm nerve defect was bridged by a collagen artificial nerve conduit. Histopathological examination revealed thin-walled dilated capillaries embedded in the fibroadipose stroma with peripheral nerve fibers, consistent with the hemangioma and intraneural extension. Postoperatively, sensibility of the radial aspect of the index finger could be completely restored, as confirmed by normal Semmes-Weinstein test results. Notably, there was no recurrence of the lesion during the 1-year follow-up.

Some reports have stated that intraneural hemangioma can be excised microsurgically, but complete excision of lesions is not always possible, and incomplete resection carries a high risk of recurrence. In such cases, an artificial nerve conduit can provide an alternative to an autologous nerve for treatment of peripheral nerve defects. Although the collagen artificial nerve conduit is considered to have some limitations for application, it facilitated a shorter surgical time and showed no unfavorable donor site morbidity, no uncomfortable feeling even in the fingers, no painful neuroma and good sensory recovery.