Pigmentierte villonoduläre - Synovialitis (PVNS) - Bildgebende Diagnostik

Pigmented Villonodular Synovitis: A Rare Case of Anterior Ankle Impingement

INTRODUCTION

Anterior ankle impingement is characterized by a painful range of motion (ROM)limitation of tibiotarsal joint. More than 70% of cases are secondary to trauma or repetitive microtrauma of the anterior aspect of the ankle such as it occurs during ball kicking ("footballer's ankle") or forced plantar flexion (ballet dancers, volleyball players, and runners) in people practicing sport for many years. There are other causes of anterior ankle impingement. We report a case of villonodular synovitis that, also less common, has to be considered in diagnostic flowchart.

CASE REPORT

In this paper, we report a rare case of pigmented villonodular synovitis (PVNS) in a 37-year-old Caucasian male soccer player, with a 4-year story of ankle swelling and ROM painful limitation.

CONCLUSION

PVNS, although it is an unusual cause of anterior ankle impingement, needs an early diagnosis and surgical excision to prevent extra-articular extension of the mass, cartilage damage, and soft tissue compression.

Pigmented villonodular synovitis: radiologic-pathologic correlation

Pigmented villonodular synovitis (PVNS) represents an uncommon benign neoplastic process that may involve the synovium of the joint diffusely or focally (PVNS) or that may occur extraarticularly in a bursa (pigmented villonodular bursitis [PVNB]) or tendon sheath (pigmented villonodular tenosynovitis [PVNTS]). Pathologic specimens of the hypertrophic synovium may appear villous, nodular, or villonodular, and hemosiderin deposition, often prominent, is seen in most cases. The knee, followed by the hip, is the most common location for PVNS or PVNB, whereas PVNTS occurs most often in the hand and foot. PVNTS is also referred to as giant cell tumor of the tendon sheath (GCTTS). PVNTS is the most common form of this disease by a ratio of approximately 3:1. Radiographs reveal nonspecific features of a joint effusion in PVNS, a focal soft-tissue mass in PVNB or PVNTS, or a normal appearance. Extrinsic erosion of bone (on both sides of the joint) may also be seen and is most frequent with intraarticular involvement of the hip (>90% of cases). Cross-sectional imaging reveals diffuse involvement of the synovium (PVNS), an intimate relationship to the tendon (PVTNS), or a typical bursal location (PVNB), findings that suggest the diagnosis. However, the magnetic resonance (MR) imaging findings of prominent low signal intensity (seen with T2-weighting) and "blooming" artifact from the hemosiderin (seen with gradient-echo sequences) are nearly pathognomonic of this diagnosis. In addition, MR imaging is optimal for evaluating lesion extent. This information is crucial to guide treatment and to achieve complete surgical resection. Recurrence is more common with diffuse intraarticular disease and is difficult to distinguish, both pathologically and radiologically, from the rare complication of malignant PVNS. Recognizing the appearances of the various types of PVNS, which reflect their pathologic characteristics, improves radiologic assessment and is important for optimal patient management.