Giant Cell Tumor of the Patella Tendon Sheath Presenting as a Painful Locked Knee

Abstract

Patient: Male, 26Final Diagnosis: Giant cell tumor of the patella tendon seathSymptoms: Efusion • locking knee • painMedication: NoneClinical Procedure: Arthroscopy and open resection of the tumorSpecialty: Orthopedics and TraumatologyObjective:Rare diseaseBackground:The giant cell tumor of the tendon sheath (GCT-TS) is a benign proliferative synovial tumor manifesting as an intra-articular solitary nodule. When it involves the infrapatellar fat pad it can present acutely as a painful locked knee.Case Report:A 26-year-old white male presented with a 2-week history of painful locking in his right knee. Clinical examination revealed lack of extension by approximately 20°. To help establish the diagnosis, an MRI scan of the right knee was performed, showing a large (5×4×2 cm), oval, well-circumscribed mass with a low-intensity homogenous signal. The size of the mass prohibited the removal by arthroscopy and we therefore proceeded with an open arthrotomy. Histological examination showed a tendosynovial giant cell tumor of the patella tendon sheath. At the latest follow-up, 2 years postoperatively, there was no local tumor recurrence.Conclusions:These rare tumorous lesions should be included in the differential diagnosis of painful locking knee, especially in the absence of definite traumatic history.

Unusual Occurrence of Tenosynovial Giant Cell Tumor in Hoffa's Fat Pad: A Potential Differential Diagnosis for Nontraumatic Knee Swelling and Pain

“…Due to nonspecific signs and symptoms, diagnosis of a giant cell tumor can be delayed for weeks or months. The common concerns may include painless or painful palpable swelling, joint effusion, locking of the knee joint, and restriction of movement [1,7,8].…”

“…Only a few cases of a large tumor of this size (in the infrapatellar region) have been reported in the literature [1,3,7,9]. Panagopoulos et al reported a case of a giant cell tumor measuring 5 cm [8]. Radiographs are of little help in diagnosing giant cell tumors because they are normal for a majority of the time, but sometimes an opacity may be observed in the infrapatellar region [1,2,8,9].…”

“…Findings specific for giant cell tumors show isointensity to muscle in T1-weighted images, whereas T2 images show low to intermediate signal intensity and intense homogeneous enhancement after contrast administration [1,7]. The diagnosis of giant cell tumors is made on a histopathological basis, which shows multinucleated giant cells with round or polygonal stromal cells [1,2,8].…”

“…The presence of residual tissue is the main cause of recurrence. We proceeded with the removal by performing open resection of the tumor due to its large size and also because the recurrence rate is less after open resection, as it allows complete removal of the tumor mass [1,2,8,9].…”

Locked knee due to fat pad adhesion

“…Most cases of locked knee are due to intra-articular blockade caused by an unstable meniscal tear, anterior cruciate ligament (ACL) tear, or chondral lesion resulting in a loose bodies. Although they are very rare, benign intra-articular tumors or tumor-like lesions can also cause the knee to lock [ 1 , 2 ]. In this case, we present a rare case of a locked knee that was caused by fat pad adhesion after injury.…”