Fibular juxta-articular ganglion: A rare case report and literature review.

This is the case report of a 65-year-old man who experienced left calf pain after spraining his left ankle. On magnetic resonance imaging (MRI), a well-defined fluid collection was identified, with low intensity on T1-weighted images and very high intensity on T2-weighted images. On certain slices, a soft tissue mass in the proximal fibula was identified. Following resection of the fibular lesion, histological examination confirmed a benign tumor with cystic elements, described in the current pathology and radiology literature as juxta-articular myxoma. This is a rarely encountered but well-recognised cystic lesion, commonly developing around the knee, that is often misdiagnosed as ganglion cyst, synovial lipoma, lipoma arborescens and pigmented or non-pigmented villonodular synovitis. Given its more cellular nature and thicker encapsulation, juxta-articular myxoma may be differentiated from ganglion cyst on MRI with a high index of suspicion, and it is crucial that it is recognized due to its high rate of recurrence. In the present case, the localization of this lesion within the fibula was uncommon, and there was also a soft tissue mass identified outside the bone. Wide resection of the lesion was performed. Recovery was uneventful and the patient remains symptom- and recurrence-free at 8-months follow-up.