Case report: Localized nodular synovitis of knee joint

Localized nodular synovitis of knee joint ISSN: 2394-0026 (P)Case Report ISSN: 2394-0034 (O)Case report: Localized nodular synovitis of knee joint Tushar M. Kalekar*Associate Professor, Department of Radiodiagnosis, D. Y. Patil Medical College, Pune, India *Corresponding author email: [email protected] to cite this article: Tushar M. Kalekar. Case report: Localized nodular synovitis of knee joint.IAIM, 2015; 2(3): 155-160.Available online at www.iaimjournal.comReceived on: 03-02-2015 Accepted on: 24-02-2015AbstractLocalized nodular synovitis is an uncommon entity with different presentations. It is a benignproliferative disorder that originates from a small area of the synovium. This disorder is found mostfrequently in the tendon sheaths of the small joints of the fingers and toes. We reported here a caseof localized nodular synovitis in a 30 years young man who came with complaints of discomfort inthe knee joint. Swelling in the infrapatellar region was diagnosed on physical examination. On MRimaging, a solitary ovoid mass lesion was identified in the infrapatellar region involving the infrapatellar fat of pad. Mild enhancement within the lesion was observed after administration ofintravenous gadolinium. There was mild to moderate joint effusions in the suprapatellar bursa. Mildsynovial enhancement was demonstrated. No meniscal or ligament tear was identified. Prospectivediagnosis based on MR imaging was localized nodular synovitis.Key wordsLocalized nodular synovitis, Knee joint, MRI.Introduction Case reportLocalized nodular synovitis is a rare disorder A 30 years young man complaining of discomfortwith different presentations. It is a benign in the knee joint region since 6 months came toproliferative disorder that originates from a our hospital. At physical examination, there wassmall area of the synovium. This disorder is swelling in the infrapatellar region. Antero-found most frequently in the tendon sheaths of posterior (AP) and lateral radiographs of leftthe small joints of the fingers and toes. We knee joint were taken. The radiograph wasreported here a case of localized nodular reported as within normal limits. (Photo – 1)synovitis in a 30 years young man diagnosed by Then after MR imaging was performed on 1.5-TMRI. siemens scanners with dedicated extremity coil. The examinations consisted principally of aInternational Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 155Copy right © 2015, IAIM, All Rights Reserved.

Localized nodular synovitis of knee joint ISSN: 2394-0026 (P) ISSN: 2394-0034 (O)combination of spin-echo T1-weighted (TR Photo – 2: Coronal T2 shows well definedrange/TE range, 450–650/15–20), spin-echo lobulated T2 hypo intense mass lesion infraproton density–weighted (1800–2200/20–30), patellar fat region.fast spin-echo T2-weighted (2500–3300/55–80),and fat-suppressed fast spin-echo proton The lesion showed intermediate signal intensitydensity-weighted 1800–2200/20– 30) and relative to that of skeletal muscle on the T1-gradient-echo (TR/TE, 650/15; flip angle, 20˚) weighted images. On the T2-weighted images,sequence in the axial plane was performed. all lesions showed inhomogeneous hypointenseVariable combinations of sequences and imaging signal. With fat suppression, lesion showedplanes were used. After these basic sequences inhomogeneous and relatively high signalwhich were routinely performed in our institute, intensity. Mild enhancement within the lesionfat-suppressed T1-weighted (TR range/TE range, was observed after administration of450–650/15–20) spin-echo imaging was intravenous gadolinium. There was mild toperformed after intravenous (IV) administration moderate joint effusions in the suprapatellarof gadolinium (0.1 mmol/kg of body weight). bursa. Mild synovial enhancement wasThe field of view varied between 14 and 16 cm, demonstrated. No meniscal or ligament tear wasthe slice thickness ranged from 3 to 5 mm, and identified. Prospective diagnosis based on MRthe inter slice gap was from 0 to 1 mm. The imaging was localized nodular synovitis. (Photonumber of acquisitions was either one or two. – 3, Photo – 4, Photo – 5)The imaging matrix ranged from 192 × 256 to256 × 256.Photo – 1: X-ray knee radiograph.MR imaging findings DiscussionOn MR imaging, a solitary ovoid mass lesion wasidentified in the infrapatellar region involving Localized nodular synovitis is a benignthe infra patellar fat of pad. (Photo - 2) It has proliferative disorder that originates from awell defined margins. The maximal diameters of small area of the synovium. This disorder isthe lesion were 4 x 5 cm. found most frequently in the tendon sheaths of the small joints of the fingers and toes [1, 2, 3, 4, 5, 6, 7]. A focal intraarticular mass is an uncommon presentation, but when it is seen, the most typical site of involvement is the kneeInternational Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 156Copy right © 2015, IAIM, All Rights Reserved.

Localized nodular synovitis of knee joint ISSN: 2394-0026 (P) ISSN: 2394-0034 (O)joint [8]. The cause of localized nodular synovitis [4, 13, 14]. The clinical manifestations ofis unclear. Although Jaffe, et al. [9] and localized nodular synovitis of the knee areGranowitz, et al. [10] suggested that localized nonspecific.nodular synovitis is an inflammatory process,more recent studies have characterized the Photo – 4: Axial STIR image revealed lobulatedlesion as a benign neoplasm of the synovium hyper intense soft tissue lesion in infra patellar[11, 12]. Traumatic, toxic, allergic, and genetic fat.factors have also been reported to beresponsible for development of this lesion [5].Patient had a discrete history of knee traumabefore the onset of knee pain. The infra patellarfat pad was the most common site ofinvolvement [5, 6, 7, 8].Photo – 3: Sagittal STIR image reveal lobulatedsoft tissue lesion in infra patellar fat showinghyper intense signal. Photo – 5: Coronal T1 post contrast image revealed lobulated soft tissue lesion in infra patellar fat showing peripheral enhancement.The suprapatellar pouch was the second most The symptoms may include pain, swelling orcommon site of involvement, although to our fullness, joint-line tenderness, restricted kneeknowledge, involvement in this area has not motion, and a palpable mass. Reportedly,been previously reported. Involvement of the localized nodular synovitis may rarely presentintercondylar notch, is relatively uncommon,having been previously reported [1, 4, 13, 14].When the cruciate ligaments are involved,localized nodular synovitis tends to morecommonly affect the posterior cruciate ligamentInternational Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 157Copy right © 2015, IAIM, All Rights Reserved.

Localized nodular synovitis of knee joint ISSN: 2394-0026 (P) ISSN: 2394-0034 (O)with locking of the knee, having been cited as serve as distinguishing observations.the cause in four patients with lesions in the Furthermore, the macroscopic appearances ofinfrapatellar fat pad [5, 6, 7]. When the maximal pigmented villonodular synovitis and localizeddiameter of the lesion in the infrapatellar pad nodular synovitis also reflect the differingexceeded 5 cm, it was likely to restrict terminal amounts of hemosiderin deposition [11, 15, 16,knee extension. Mechanical impingement may 17, 18]. Another important distinguishingalso stimulate the release of chemical substance feature between pigmented villonodularP, which is rich in the synovial lining of the synovitis and localized nodular synovitis is ininfrapatellar fat pad, inducing pain. The their growth. As pigmented villonodularobservation of a pedicle is relevant because synovitis becomes more involved, the synovialtorsion of this pedicle can produce acute knee masses constrict the joint, whereas localizedpain, which was seen in one of our patients. nodular synovitis tends to grow outward,However, this condition can be difficult to becoming pedunculated. The differentialdiagnose unless images are carefully inspected. diagnoses of a mass in the infrapatellar fat padThe MR imaging appearance of intraarticular include several pathologic processes. Hoffa’slocalized nodular synovitis is variable. Typically, disease is an entity characterized byintraarticular localized nodular synovitis appears inflammation and fibrosis of the infrapatellar fateither as a well-defined, small ovoid lesion or as body. The ill-defined margin of the lesion, oftena large polylobulated soft-tissue mass with iso- associated with edema, is characteristic of theor hyper intense signal intensity relative to posttraumatic process. Chondroma orskeletal muscle on T1-weighted images and osteochondroma of the infrapatellar fat pad hasvariable signal intensity on T2-weighted images. a signal intensity pattern consistent with eitherCircular regions of intermixed low signal cartilage or bone marrow and lacks theintensity corresponded to regions of high deposition of hemosiderin. Other lesions such ashemosiderin concentration, and the conspicuity a tophus from gout and focal arthrofibrosis doof this pattern increased on gradient-echo I not typically have the same characteristics asmages. In addition, an internal cleft like or linear localized nodular synovitis. Surgical interventionhigh-signal intensity region of the lesion in T2- is the best therapeutic choice for patients withweighted images was identified. We speculate localized nodular synovitis. Complete excision ofthat this finding may relate to tissue necrosis. the lesion usually is accomplished by eitherEnhancement of localized nodular synovitis is arthroscopy or open arthrotomy, and thepresumably related to the presence of decision for which procedure to performnumerous proliferative capillaries in the depends on the location and size of the lesion.collagenous stroma [13]. Although intra articular Recurrence is rare unless the lesion is notlocalized nodular synovitis shares similar excised completely, and to our knowledge,histologic characteristics with pigmented recurrence has been described only twice in thevillonodular synovitis, these entities have been literature [6, 11].considered to represent different manifestationsof synovial proliferation [9, 11, 15, 16, 17, 18]. ConclusionCharacteristic features of pigmentedvillonodular synovitis, not found in localized In summary, intra articular localized nodularnodular synovitis, are the presence of diffuse synovitis most commonly involves the infrafrondlike projections of synovium and an patellar fat pad. The clinical presentation isabundance of hemosiderin deposition, which variable but may mimic mechanicalInternational Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 158Copy right © 2015, IAIM, All Rights Reserved.

Localized nodular synovitis of knee joint ISSN: 2394-0026 (P) ISSN: 2394-0034 (O)derangement of the knee. MR imaging can 8. Llauger J, Palmer J, Roson N, Cremadesfacilitate preoperative diagnosis and provide R, Bague S. Pigmented villonodularinformation important for surgical planning. synovitis and giant cell tumors of theMany features help to distinguish localized tendon sheath: Radiologic andnodular synovitis from pigmented villonodular pathologic features. AJR, 1999; 172:synovitis, including the appearance of a smooth 1087-1091.surface, involvement of a small region of 9. Jaffe HL, Lichtenstein L, Sutro CJ.synovium, small tumoral volume of hemosiderin, Pigmented villonodular synovitis,and the absence of a hemorrhagic joint effusion. bursitis, and tenosynovitis. Arch Pathol, 1941; 31: 731-765.References 10. Granowitz SP, D’Antonio J, Mankin HL. The pathogenesis and long-term end 1. Jelinek JM, Kransdorf MJ, Shmookler results of pigmented villonodular BM, Aboulafia AA, Malawer MM. Giant synovitis. Clin Orthop, 1976; 114: 335- cell tumor of the tendon sheath: MR 351. findings in nine cases. AJR, 1994; 162: 11. Rao AS, Vigorta VJ. Pigmented 919-922. villonodular synovitis (giant-cell tumor of the tendon sheath and synovial 2. Karasick D, Karasick S. Giant cell tumor membrane): A review of eighty-one of tendon sheath: Spectrum of cases. J Bone Joint Surg Am, 1984; 66: radiologic findings. Skeletal Radiol, 76-79. 1992; 21: 219-224. 12. Schwartz HS, Unni KK, Pritchard DJ. Pigmented Villonodular synovitis: A 3. Sundaram M, McGuire MH, Fletcher J, retrospective review of affected large Wolverson MK, Heiberg E, Shields JB. joints. Clin Orthop, 1989; 247: 243-255. Magnetic resonance imaging of lesions 13. Beuckeleer LD, Schepper AD, Belder FD, of synovial origin. Skeletal Radiol, 1986; et al. Magnetic resonance imaging of 15: 110-116. localized giant cell tumour of the tendon sheath (MRI of localized GCTTS). Eur 4. Sheppard DG, Kim EE, Yasko AW, Ayala Radiol, 1997; 7: 198-201. A. Giant cell tumor of the tendon sheath 14. Balsara ZN, Stainken BF, Martinez AJ. arising from the posterior cruciate MR image of localized giant cell tumor ligament of the knee: A case report and arising from the anterior cruciate review of the literature. Clin Imaging, ligament of the knee. Arthroscopy, 1998; 22: 428-430. 1996; 15: 496-499. 15. Wright C. Benign giant cell synovioma: 5. Nau T, Chiari C, Seita H, Weixler G, An investigation of 85 cases. Br J Surg, Krenn M. Giant-cell tumor of the 1951; 38: 257-271. synovial membrane: Localized nodular 16. Ushijima M, Hashimoto HM, Tsuneyoshi synovitis in the knee joint. Arthroscopy, M, et al. Giant cell tumor of the tendon 2000; 16: E22. sheath. Cancer, 1986; 57: 875-884. 17. Enzinger FM, Weiss SW. Soft tissue 6. Fraire AE, Fechner RE. Intra-articular tumors, 3rd edition, St. Louis: Mosby, localized nodular synovitis of the knee. 1994, p. 735-755. Arch Pathol, 1972; 93: 473-476. 7. Testa NN, Williams LA, Klein MJ. An unusual cause of knee locking: a case report. Clin Orthop, 1978; 134: 174-175.International Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 159Copy right © 2015, IAIM, All Rights Reserved.

Localized nodular synovitis of knee joint ISSN: 2394-0026 (P) ISSN: 2394-0034 (O) 18. Hughes TH, Sartoris DJ, Schweitzer ME, Resnick DL. Pigmented villonodular Conflict of interest: None declared. synovitis: MRI characteristics. Skeletal Radiol, 1995; 24(1): 7-12.Source of support: NilInternational Archives of Integrated Medicine, Vol. 2, Issue 3, March, 2015. Page 160Copy right © 2015, IAIM, All Rights Reserved.