gms | German Medical Science

Objective: Fibrolipomatous Hamartomas (FLH) are rare lesions caused by anomalous growth of fibro-adipose tissue of the nerve sheath, leading to gross enlargement of the affected nerve. It most commonly manifests at the median nerve. Although often present early in life, FLH is mostly symptomatic later in life, mostly beyond the second decade. We report on typical clinical/radiological findings, symptomatology and management based on two very eraly symptomatic cases and literature review.

Method: A 19m-old asymptomatic girl received diagnostic work-up because of macrodactyly of finger II/III, swelling of radial palm and wrist. A 5y-old boy was treated for 2 years for increasingly painful swelling of left wrist, thought to be juvenile rheumatoid arthritis. He received full medical treatment including immunosuppressants without effect

Results: Both children had macrodactyly of finger II&III and soft tissue swelling extending from distal forearm/wrist over radial palm side to affected fingers. MRI showed characteristic and diagnostic findings of FHL, which render biopsy unnecessary. High resolution ultrasound (US) could be shown to be equally diagnostic. Both lesions did not grow within 2 years. The asymptomatic girl developed median nerve compression symptomatology within one year, which responded for another year to splint immobilization at night. Then pain become unbearable. Both patients underwent carpal tunnel and perineural tissue release. Symptoms disappeared immediately postoperatively. In US and MRI disappearance of nerve compression was demonstrated.

Conclusions: FLH is a rare but – if recognized – highly characteristic lesion, which can be diagnosed by typical clinical and imaging findings. As reported, a misdiagnosis is nevertheless possible, if pain and swelling are put in different context and if macrodactyly is mild/absent. Most reported cases (<50) are symptomatic beyond the second decade. Up to our knowledge these are the youngest ever reported symptomatic cases. Treatment aims at surgical pressure release. Attempts of resection will result in loss of function in a benign disease and are not justifiable.