LIPOFIBROMATOUS HAMARTOMA OF PERIPHERAL NERVE- A RARE AND CHALLENGING ENTITY

Lipofibromatous Hamartoma (LFH) is rare condition involving diffuse peripheral nerve infiltration by normal appearing fibrous and adipose tissues. The cause and pathophysiology of LFH remains unclear however commonly proposed etiologies are congenital malformation and trauma. LFH affect the median nerve mainly but also buccinators, sciatic, superficial peroneal, posterior interosseous nerve, radial nerve, ulnar nerve, even the entire brachial plexus. Patients present with gradually enlarging non-tender lesions in the affected nerve distribution. Patient complains of numbness and tingling sensation. Motor deficits are a late finding. The majority of cases are diagnosed within the first three decades, with a mean age of 22.3 in remote cases and 22.0 in subjects presenting with macrodactyly. There are numerous overlapping clinical features with other conditions like klippal-Trenaunay-Weber syndrome, Hypertropic mononeuritis and congenital lymphedema. Upper extremity morphology includes mass, hypertrophy, macrodactyly, syndactyl, radial or ulnar deviation of phalanx , neurological symptoms including dysesthesia, paresthesia, motor deficits, cafe-au- lait spots, port wine stains, neurofibromatosis. On physical examination, the mass is soft, firm, nonfluctuant, mobile, minimally tender. Neurological deficits associated with LFH are hypesthesia, decreased grip, pinch, opposition strength and paraesthesia, yielding positive Tinel's and phalen's test. Tumors mimicking LFH of the median nerve include ganglion cyst, Déjerine Sottas disease, Klippel-Trénaunay-Weber syndrome, lipoma, and traumatic neuroma, neurofibroma and schwannoma. MRI, CT, Nerve Conduction Study, Electromyogram gets us closer to the diagnosis. Biopsy and histopathological examination are the only definitive means of LFH diagnosis. Care must be taken to rule out potentially malignant tumors. Treatment goals for LFH are symptom prevention, symptomatic relief, function, and aesthetics. Conservative approach can be offered to patients who present with an asymptomatic swelling without severe neurological impairment. There are two options of surgery. One is staged debulking and other Epiphysiodesis in a growing child. For cosmetic reasons, surgical debulking can only be undertaken if the risk of nerve damage is minimal. Digital amputation is usually reserved for severe cases refractory to debulking procedures.