Fibrolipomatous hamartoma of nerve and macrodystrophia lipomatosa are rare conditions that present characteristic imaging findings. The plain films, magnetic resonance imaging studies and medical records of four patients were reviewed. The lesion was resected in one patient allowing histological confirmation of the diagnosis. Diagnosis was based on imaging and clinical findings in three patients who had unavailable biopsy data. We describe two cases of isolated macrodystrophia lipomatosa, one case of fibrolipomatous hamartoma and one case where both conditions were found. In the macrodystrophia lipomatosa cases plain films demonstrated enlargement of osseous and soft tissue structures in the affected limbs, with fatty streaks interspersed along the muscle fibers. The median nerve was affected in the cases of fibrolipomatous hamartoma. Magnetic resonance imaging findings included nerve fascicle thickening characterized by low signal on both T1 and T2-weighted sequences, and surrounding fat, which appears as high signal on T1 and low signal on T2-weighted sequences with fat saturation. Both nerves had a "coaxial cable" appearance on axial images. The fibrolipomatous hamartoma extended to the nerve branches, which is a typical finding. The typical imaging findings of macrodystrophia lipomatosa and fibrolipomatous hamartoma of nerve, particularly at magnetic resonance imaging examination, allowed a reliable diagnosis of these frequently coexistent conditions.
Macrodystrophia lipomatosa; Fibrolipomatous hamartoma; Magnetic resonance imaging; Peripheral nerve disease; Median nerve
