Case Author(s): Gregg D. Schubach, M.D. and Jerold W. Wallis, M.D. , . Rating: #D2, #Q5

Diagnosis: Giant Cell Tumor

Brief history:

29-year old man with left knee pain for several weeks.


Anterior Flow Images... (upper left image is immediate static/blood pool image)

View main image(bs) in a separate image viewer

View second image(bs). Anterior and Posterior whole body delayed images and spot view left knee

View third image(xr). AP and lateral of left knee

View fourth image(mr). T1, Proton density, and T2 coronal images

Full history/Diagnosis is available below

Diagnosis: Giant Cell Tumor

Full history:

29-year old man with left knee pain. There is no history of trauma, primary malignancy, musculoskeletal disorders, or other pertinent past medical problems. The patient presents to Nuclear Medicine following plain radiographs and an MRI examination of the left knee.


Tc-99m MDP i.v.


Three-phase bone scintigraphy demonstrates increased flow and delayed radiopharmaceutical uptake to the lateral aspect of the left tibial plateau. The lateral view confirms that the major finding is in the tibial plateau rather than the patella. The plain radiograph dated 10-4-95 reveals a lytic ³end-of-bone² lesion along the lateral aspect of the left tibial plateau. The lesion is characterized by a non- mineralized matrix, narrow zone of transition, and no sclerotic rim. The MRI study demonstrates a 2 x 3 x 3 cm mass occupying the lateral aspect of the left tibial plateau. The lesion is sharply demarcated from the marrow in its medial aspect, but abuts the cortex laterally and posteriorly (only coronal images shown). The lesion is low signal intensity on T1 images and high signal intensity on T2 weighted images. The cortex is disrupted through the superior aspect of the lateral margin of the tibial plateau, posterior margin, as well as the articular surface. The mass extends outside of the bone and beneath the posterior horn of the lateral meniscus. The mass bows the collateral ligament slightly laterally. The medial collateral, cruciate, and the patellar ligaments appear intact.


Giant cell tumors, which are also called osteoclastomas, account for approximately 4% of all primary bone tumors and approximately 21% of all benign skeletal tumors. Giant cell tumors affect men and women with equal frequency and typically occur between ages 20 and 40 years. This lesion is rare in children. Giant cell tumors are typically eccentric ³end-of-bone² lesions seen in long bones with 50-60% about the knee. The lesion is characterized by a non-mineralized matrix, narrow zone of transition, and no sclerotic rim. 25% demonstrate soft tissue invasion and 5% are complicated by a pathologic fracture. Uptake on bone scintigraphy is typically intense, and may extend slighlty beyond the limits of the tumor. 85% of the giant cell tumors are benign. However, the giant cell tumor is a neoplasm which, although appearing histologically benign, may metastasize. Case reports in the recent literature describe metastatic lung nodules which, upon surgical resection, demonstrate giant cell lesions with clearly benign histopathology. Thus, the surgical resection of the ³mets², along with treatment of the primary lesion (usually by curettage and grafting) is considered curative. The rate of recurrence of a giant cell tumor is about 40-60% with most recurrences occurring within two years after treatment and usually at the site of the primary tumor.

Bone scintigraphy was performed primarily to look for additional bone lesions. Three-phase (rather than single-phase) scintigraphy was performed for academic interest at no additional cost to the patient.

References: Resnik. Bone and Joint Imaging. 1989


The patient underwent curettage of the lesion with bone grafting and/or packing with bone chips.

Major teaching point(s):

1) Many bone abnormalities, including neoplasms, are ³hot² on three-phase bone scintigraphy. Most neoplasms demonstrate increased vascularity; hence, there is increased flow on the scintigraphic angiogram. Demonstrating this is of no additional diagnostic value; however, it is useful to note that tumor remains in the differential when three-phase scintigraphy is used for other reasons (e.g. to assess for osteomyelitis).

2) Giant cell tumors have a classic radiographic appearance including; a) an ³end-of-bone² lesion, b) no sclerotic rim, and c) no mineralized matrix.

3) Specific age range at presentation (20-40 yrs) is helpful in distinguishing similarly appearing lesions.

Differential Diagnosis List

The classic ³end-of-bone² lesions include: 1) Giant cell tumor; 2) Chondroblastoma; 3) Intraosseous ganglion; 4) Chondrosarcoma (clear cell); and 5) Pagetıs disease. Chondroblastoma typically occurs in a child or adolescent and may contain chondroid calcifications. The intraosseous ganglion is observed most frequently in the medial malleolus of the tibia, in the carpal bones, or the periarticular regions such as the hip. The radiographic appearance and age at presentation are characteristic of giant cell tumor. If multiple giant cell tumors are being considered, brown tumors (seen in hyperparathyroidism) should be considered. Based on the scintigraphic appearance alone, the differential would include tumor, fracture, healing avascular necrosis, and osteomyelitis.

ACR Codes and Keywords:

References and General Discussion of Bone Scintigraphy (Anatomic field:Skeletal System, Category:Neoplasm, Neoplastic-like condition)

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Case number: bs047

Copyright by Wash U MO