RESUMO
BACKGROUND: Lymphangiomas are benign lymphatic vessel hamartomas typically found in the skin or subcutaneous tissue of the head and neck. Although mostly seen in a congenital context, acquired forms have been reported. By contrast, cavernous hemangiomas are benign hamartomas of endothelial origin. They can arise anywhere in the body, but are typically described as arising from the central nervous system. METHODS: We report the case of a young patient who developed a mixed lymphangioma and cavernous hemangioma within the ulnar nerve. The tumor was removed during an intrafascicular dissection with preservation of all major fascicles. RESULTS: Postoperatively, the patient retained intrinsic motor function and full sensation returned. This is the first published case of this type of mixed tumor occurring in a peripheral nerve. CONCLUSIONS: It could not be ascertained whether trauma was the mechanism by which a lymphangioma developed within the peripheral nerve, as has been proposed. Although this is plausible, alternative mechanisms should be considered.