Endoneural abscess of common popliteal nerve as first clinical manifestation of leprosy: the first reported case in history in a low-incidence country

A migrant from Palestine came to our attention for weakness of dorsiflexion of the left foot and hypoesthesia of the homolateral common peroneal nerve territory. Skin biopsies from skin lesions in the hypoesthetic area were not diagnostic. Radiological investigation showed focal nerve enlargement with a possible focal lesion. At this time, and given the uncertainty of the diagnosis, we had to choose between medical therapy with steroid and a surgical exploration of the nerve. We decided for the latter option. Intraoperatively, we found a focal round enlargement of the nerve. Epineurotomy was performed at that level, revealing a round caseous granulomatous mass that was excised. Microbiological examination revealed presence of Mycobacterium Leprae allowing diagnosis of leprosy. Medical therapy was then started, leading to resolution of clinical symptoms. Endoneural lepromatous abscesses are uncommon lesions that should be suspected in patients presenting with peripheral nerve dysfunction with anamnesis of travel in leprosy endemic regions or contacts with people from endemic regions with or even without skin lesions. Detection of endoneural abscesses is of critical importance because prompt surgical excision in conjunction with medical therapy leads to improvement of symptoms and permits correct diagnosis. In times of large human migrations from leprosy endemic areas, knowledge of this uncommon presentation of leprosy and its management will help lead to the best management of these patients.