Intraarticular fibroma of the tendon sheath of the knee

Intra-articular fibroma of the tendon sheath of the knee involving a teenager: a case report and review of the literature

“…Other reports suggest that the signal characteristics could vary from intermediate to low or isointense to muscle with heterogeneity [3][4][5]. Generally, the T1-weighted MR images typically show a well-defined lesion with homogenous low or iso-signal intensity compared with the muscle [1,3,6,[8][9][10]. On the T2-weighted images, most of the cases show a mixture of low and high signal intensity [3,6,7].…”

“…Generally, the T1-weighted MR images typically show a well-defined lesion with homogenous low or iso-signal intensity compared with the muscle [1,3,6,[8][9][10]. On the T2-weighted images, most of the cases show a mixture of low and high signal intensity [3,6,7]. Peripheral hypointense areas on the T2-weighted images correspond to highly collagenous stroma with hypocellularity and central hyperintense areas corresponding to a myxoid region [1,3,6].…”

“…On the T2-weighted images, most of the cases show a mixture of low and high signal intensity [3,6,7]. Peripheral hypointense areas on the T2-weighted images correspond to highly collagenous stroma with hypocellularity and central hyperintense areas corresponding to a myxoid region [1,3,6]. MR findings of gadolinium enhancement vary from homogenous enhancement [6], no enhancement [5], to peripheral enhancement [9].…”

“…FTS rarely occurs in the synovial membrane of the joint capsule; in such cases, symptom of onset is rather joint discomfort or swelling. Intra-articular FTS of the knee is rare, considering that only eight previous cases have been reported in the English literature [1][2][3][4][5][6][7]: two in the infrapatellar fat pad, one in the posterior cruciate ligament (PCL), one in the suprapatellar pouch, one in the posterior joint capsule, and one located between the posterior capsule and the PCL. We describe the ninth case of FTS located in the intercondylar space dorsal to the PCL of a teenager's knee.…”

Differential diagnosis of tumours and tumour-like lesions of the infrapatellar (Hoffa?s) fat pad: pictorial review with an emphasis on MR imaging

“…These include a single case of a fibroma of the tendon sheath involving the IFP with some MR features suggestive of focal PVNS [84]. The only other case recognised in the knee arose in the suprapatellar fossa [85]. A tiny glomus tumour has also been described in the IFP [86].…”