Pigmented villonodular bursitis/diffuse giant cell tumor of the pes anserine bursa: A report of two cases and review of literature
Pigmented villonodular synovitis (PVNS) is a benign but potentially aggressive lesion, characterized by synovial villonodular proliferation with hemosiderin pigmentation and stromal infiltration of histiocytes and giant cells. This consists of a common family of lesions, including localized and diffuse forms of pigmented villonodular synovitis, giant cell tumor of the tendon sheath (nodular tenosynovitis) and the very rare cases of extra-articular pigmented villonodular synovitis arising from the bursa (pigmented villonodular bursitis or diffuse giant cell tumor of the tendon sheath). The purpose of this paper is to present two rare cases of pigmented villonodular bursitis arising from the pes anserinus bursa. The various differentials along with a review of literature of similar lesions are also being discussed. However, as with other lesions, clinicoradiographic features along with close histological correlation is essential for diagnosis.
[Show abstract] [Hide abstract] ABSTRACT: Objectives and methods: A variety of benign cystic or "cyst-like" lesions may be encountered during a routine magnetic resonance imaging (MRI) of the knee. These lesions comprise a diverse group of entities from benign cysts to complications of underlying diseases. In addition, normal anatomic bursae and recesses may be misdiagnosed as an intra-articular cystic lesion when they are distended. However, the majority of the aforementioned lesions have characteristic MR appearances that allow a confident diagnosis, thus obviating the need for additional imaging or interventional procedures. Results: This article includes a comprehensive pictorial essay of the characteristic MRI features of common and uncommon benign cysts and "cyst-like" lesions in and around the knee joint. Discussion: For accurate assessment of the "cystic structure", a radiologist should be able to identify typical MRI patterns that contribute in establishing the correct diagnosis and thus guiding specific therapy and avoiding unwarranted interventional procedures such as biopsy or arthroscopy. Teaching points: • Cystic lesions are common in knee MRI and the commonest, the Baker's cyst, has an incidence of 38 %. • Synovial cysts, meniscal cysts, normal knee bursae and recesses have characteristic MR appearances. • Miscellaneous "cyst-like" lesions may require a more dedicated MR protocol for a correct diagnosis.0Comments 6Citations
- "The anserine bursa lies deep to the pes anserinus, superficial to the tibial insertion of the medial collateral ligament and the medial tibial condyle, and slightly distal to the insertion of the semimembranosus tendon [35–37]. Clinically, anserine bursitis may mimic a medial meniscus tear or injury of the MCL and is more commonly seen as a sports injury in runners [1, 2, 6–9, 35]. "
[Show abstract] [Hide abstract] ABSTRACT: Pigmented villonodular synovitis (PVNS) is a rare, benign, proliferating disease affecting the synovium of joints, bursae, and tendon sheaths. Involvement of bursa (PVNB, pigmented villonodular bursitis) is the least common, and only few cases of exclusively extra-articular PVNB of the pes anserinus bursa have been reported so far. We report a case of extra-articular pes anserine PVNB along with a review of the literature. The lesion presented as a painful soft tissue mass in the medial part of the proximal leg. A magnetic resonance imaging showed areas of low to intermediate signals in all sequences and the lesion enhanced heterogeneously with contrast. Diagnosis was confirmed by an incisional biopsy, and an intralesional resection was performed. The postoperative course was uneventful, and the patient is free of disease with no functional deficit at 2 years followup. As with other rare lesions, clinical and radiographic findings in addition to histological examination are essential for correct diagnosis.0Comments 4Citations
- "Eckhardt and Hernandez  reported that PVNS was well visualized on both proton density-weighted images and gradient-echo images despite the blurring effect of hemosiderin-laden macrophages. The clinical differential diagnosis includes simple bursal cyst, neurofibroma, fibroma of tendon sheath, or a heman- gioma1234567891011 14]. A typical pes anserinus bursitis, meniscal, or ganglion cyst, may present with bursal fluid and characteristic MRI signal. "
- [Show abstract] [Hide abstract] ABSTRACT: In this paper, for frontal view face recognition hybrid approaches using neural networks (NNs) and hidden Markov models (HMMs) are proposed. In the preprocessing stage, edges of a face are detected using the conventional locally adaptive threshold (LAT) scheme and facial features are extracted based on generic knowledge of facial components. In constructing a database with normalized features, we employ HMM parameters of each person computed by the forward-backward algorithm. Computer simulation shows that the proposed HMM-NN algorithm yields higher recognition rate compared with several conventional face recognition algorithms0Comments 2Citations