Fibrolipomatous hamartoma of the median nerve: A cause of acute bilateral carpal tunnel syndrome in a three-year-old child: A case report and comprehensive literature review

Abstract

A lthough carpal tunnel syndrome (CTS) is the most common entrapment neuropathy encountered in an adult surgical practice, it is relatively rare in children. In the majority of adults, CTS is believed to be idiopathic in origin. However, in children, CTS is usually secondary to an underlying pathology, such as lysosomal storage diseases, particularly mucopolysaccharidosis and mucolipidosis. Other causes of CTS in children include genetic bony dysplasia, malformations of the anatomical structures of the carpal tunnel, or enlargement of the median nerve by intraneural lipoma, ganglionic cysts, traumatic neuromas, vascular malformations or neurofibromas. An unusual cause of childhood CTS is fibrolipomatous hamartoma (FLH), a rare benign lesion characterized histologically by the presence of mature fat cells admixed with fibroblastic proliferation within the distorted, expanded nerve bundles.We report the first case in the published literature of acute bilateral CTS secondary to bilateral FLH of the median nerves without macrodactyly in a three-year-old boy who presented with incessant crying due to acute bilateral compression neuropathy. Case presentationA three-year-old boy was brought to the emergency room by his mother due to 'incessant crying' that began earlier that morning. His distress had been progressive since he awoke and, on arrival to the emergency room, he was inconsolable. The mother was unable to identify a precipitating cause. On further questioning, the mother recalled his complaining of discomfort in the right wrist for the past three months. The boy was otherwise healthy, took no medications and his immunizations were up to date.On physical examination, a 4 cm to 5 cm swelling of the flexor aspect of the right wrist and thenar atrophy of this hand were recognized with associated weakness in the hand ( Figures 1A and 1B). Tinel's test was positive. The boy's distress escalated with active and passive movement of the wrist, which impeded the assessment of sensation and range of motion. His physical examination was otherwise unremarkable except for an incomplete syndactyly of the second and third toes.Suspecting a neurofibroma secondary to neurofibromatosis, dermatology and ophthalmology were consulted. A complete workup for the same showed no stigmata of neurofibromatosis. Plastic surgery was subsequently consulted to perform an examination under anesthetic for exploration of the right wrist. Intraoperatively, a fusiform enlargement of the median nerve causing carpal tunnel compression was identified (Figures 2A to 2C). The surrounding tissue was otherwise normal. A biopsy of the median nerve was taken for diagnostic purposes, and a carpal tunnel release (CTR) was performed to alleviate compression symptoms. A three-year-old boy was investigated for inexplicable incessant crying. On examination, his left wrist was mildly swollen (three to four months) and sensitive. Exploration and carpal tunnel decompression of the left wrist with incisional biopsy was performed for the presence of a fusiform swe...

Lipofibromatous Hamartoma of the Palmar Cutaneous Branch of the Median Nerve

“…Two recent articles provide excellent extensive reviews of the literature and discuss details of diagnosis at length. 4,8 The authors thus focus on essential principles and their specific thought process in their management of this expanding palmar mass in a child.…”

“…The most common age of presentation is in the 30s to 40s, but case reports of a pediatric median nerve LFH have been published. [8][9][10] Young patients are more likely to also exhibit macrodactyly. 11 Symptoms are often related to the location of its presentation; when occurring in the median nerve, it may lead to dysfunction of median nerve innervated muscle, sensory impairment of the skin, and most commonly this can mimic carpal tunnel syndrome due to its mass effect.…”

Lipofibromatous hamartoma of the median nerve – A case report

“…1 The differential diagnosis based on clinical examination includes vascular malformations, ganglion cysts, lipomas and traumatic neuromas. 4 Patients typically present in childhood with macrodactyly or at adolescence with a volar forearm mass. 2 The median nerve is the most common nerve affected, with an incidence between 66% and 80% of cases.…”

“…4 Patients typically present in childhood with macrodactyly or at adolescence with a volar forearm mass. 4 The diagnosis of LFH is strongly supported by imaging findings. 3 Associated symptoms include numbness and pain along the motor/sensory distribution of the nerve.…”

Congenital Bilateral Thenar Amyotrophy due to Carpal Tunnel Narrowing

“…In pediatric patients, median nerve (MN) mononeuropathy is rarely documented. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] In this population, TMA has more often been attributed to malformations of the radial carpal bones (►Table 1), the most frequent of which is a regional defect known as Cavanagh syndrome. 3 Structural malformations cause the atrophy through different mechanisms, among which are disuse arising from low joint motility, anomalous muscle insertion, and muscle agenesis and/or hypoplasia.…”