Epithelioid malignant peripheral nerve sheath tumour of the ulnar nerve around the elbow: a diagnostic and therapeutic challenge.

Epithelioid malignant peripheral nerve sheath tumour (EMPNST) is a rare histological subtype of malignant peripheral nerve sheath tumour (MPNST), accounting for 5% to 17% of MPNSTs. The clinical and MRI findings of EMPNST mimic those of nerve abscesses, similar to the presentation in Hansen's disease. We present one such case with this kind of diagnostic dilemma. Intraoperative findings suggest a tumour changed the course of management subsequently. The development of neurological deficits postoperatively after tumour resection was a reconstructive challenge. To provide motor power and sensation through a procedure that provides a complete functional outcome for a young patient, distal nerve transfers were chosen. This provided an improvement in the quality of life and hastened the neurological recovery of the involved limb. Level of evidence: V.

Nerve abscess in pure neural leprosy mistaken for peripheral nerve sheath tumour with disastrous consequence: what can we learn?

A 34-year-old Indian man presented to an orthopaedician with gradually progressive hypoesthesia affecting his right lower limb and an ipsilateral common peroneal nerve swelling around the knee. The nerve swelling was diagnosed as a peripheral nerve sheath tumour based on MRI findings and was excised, only to be revealed as leprous nerve abscess on histopathology later. The patient developed right foot drop as a result of common peroneal nerve biopsy. This case presents several learning points in the diagnosis of pure neural leprosy.