Multifocal pigmented villonodular synovitis coexisting in both the knee joint and the patella: a case report and literature review

Abstract

BackgroudPigmented villonodular synovitis (PVNS) is an uncommon entity of proliferative lesion of the synovium, presenting with different clinical signs and symptoms. PVNS rarely forms an osteolytic lesion in a bone. Here we report a unique case of PVNS with a nodular lesion in the left patella.Case presentationA 37-year-old female was referred to our hospital with complaints of ongoing left knee pain and a painful and palpable mass in her left popliteal fossa. MRI demonstrated a nodular lesion in the left patella, diffuse affected synovial tissue in the left knee and an extra-articular mass in the left popliteal fossa. After a primary diagnosis of PVNS had been established, combined arthroscopic synovectomy and open resection were performed. The postoperative pathological diagnoses of the resected mass from the popliteal fossa, the affected synovial tissue and the lesion in the patella were consistent with PVNS. At 1-year follow-up, no evidence of recurrence was noted.ConclusionsBased on brief literature review of PNVS, we presented a very rare case of PVNS with a nodular lesion in the left patella, diffuse affected synovial tissue in the left knee and an extra-articular mass in the left popliteal fossa.

Pacydermoperiostosis Associated With Pigmented Villonodular Synovitis

“…The etiology is uncertain, but mutations in the Colony -Stimulating Factor 1 (CSF-1) gene with overexpression of CSF-1 have been described in some cases of PVNS [9]. Joint pain, chronic swelling and limitation of the joint mobility are the most common clinical manifestations and because of nonspecificity of signs and symptoms there is usually a delay in diagnosis [8][9][10][11]. The laboratory tests are normal.…”

“…The laboratory tests are normal. The radiographic examination is normal in the early phases but later it shows joint swelling, bone erosions and subcondral cysts [8][9][10][11]. Computed Tomography (CT) shows synovial thickening and bone erosions.…”

“…MRI reveals synovial thickening with low to intermediate signal on T1 -weighted images and low signal in T2 -weighted images with enlargement of low signal intensity areas in the gradient echo images ("blooming effect") very specific for the presence of hemosiderin in the synovial tissue [9][10][11]. The most effective treatment is synovectomy [8][9][10][11]. Radiation therapy, external or intra articular, is also used for PVNS [8][9][10][11].…”

“…Refractory synovitis is rarely reported in pachydermoperiostosis [7]. Pigmented Villonodular Synovitis (PVNS) is a rare, usually benign, villous or nodular synovial proliferation of joints, tendons and bursae [8][9][10][11]. The pigmentation is generated by the accumulation of hemosiderin in the synovial proliferation [10,11].…”

“…The pigmented villonodular tenosynovitis (giant -cell tenosynovitis) is the most frequent manifestation of the disease [9][10][11]. The knee is the most frequent affected joint, followed by the hip, and then some others joints as elbow, shoulder and ankle [8][9][10][11]. The etiology is uncertain, but mutations in the Colony -Stimulating Factor 1 (CSF-1) gene with overexpression of CSF-1 have been described in some cases of PVNS [9].…”