A Mass With High Uptake of Fluorodeoxyglucose on Positron Emission Tomography | Oncology | JN Learning | AMA Ed Hub [Skip to Content]
[Skip to Content Landing]

A Mass With High Uptake of Fluorodeoxyglucose on Positron Emission Tomography

Educational Objective
Based on this clinical scenario and the accompanying image, understand how to arrive at a correct diagnosis.
1 Credit CME

An adolescent girl presented with a 3-month history of a growing, painless mass in the right thigh. A magnetic resonance imaging (MRI) scan showed an inhomogeneous nodule in the subcutaneous layer with a largest diameter of approximately 5 cm. No enlarged lymph nodes were detectable in the groin. Results of a complete blood cell count and levels of alkaline phosphatase, lactic dehydrogenase, and C-reactive protein were unremarkable. An ultrasonography-guided core needle biopsy was performed, and histopathologic evaluation showed the aspects of a small round-cell tumor, which was confirmed to be a Ewing sarcoma by immunohistochemical and molecular analysis (with positivity for the EWS-FLI1 fusion gene [OMIM 133450]). The patient then underwent disease staging with computed tomography (CT) of the chest and whole-body fluorodeoxyglucose positron emission tomography (FDG-PET). The CT findings were negative for secondary lesions; the FDG-PET scan demonstrated, as expected, high uptake in the right thigh (maximum standard uptake variable [SUVmax], 8.4) at the site of the subcutaneous tumor and at a second lesion in the left ankle joint (SUVmax, 12.0). The patient reported vague pain around the left ankle but no functional limitations and no history of trauma at that site. A radiograph of the ankle did not show calcifications within the soft-tissue lesion. An MRI scan of the ankle showed a 1.5-cm soft tissue mass in the posterior recess of the ankle joint with a low to intermediate signal in T1- and T2-weighted sequences and moderate contrast enhancement throughout the lesion (Figure 1).

Please finish quiz first before checking answer.

You answered correctly!

Read the answer below and download your certificate.

You answered incorrectly.

Read the discussion below and retake the quiz.

B. Tenosynovial giant cell tumor

The nodule in the ankle joint with low to intermediate intensity signal on T1- and T2-weighted images and diffuse contrast enhancement was highly suggestive of a tenosynovial giant cell tumor (TGCT). Ganglion cysts appear with a homogeneous high-intensity T2-weighted signal and do not show central contrast enhancement or high uptake on FDG-PET. Synovial sarcoma is a rare soft-tissue tumor that is intra-articular only in about 10% of the cases. This tumor usually shows an inhomogeneous high-intensity signal on T2-weighted MRI scans. A similar radiologic presentation would also be expected in case of a soft-tissue metastasis from an Ewing sarcoma, which is a rare event.1 Synovial sarcoma shows calcifications within the tumor in approximately 30% of cases.

Survey Complete!

Sign in to take quiz and track your certificates

Buy This Activity

JN Learning™ is the home for CME and MOC from the JAMA Network. Search by specialty or US state and earn AMA PRA Category 1 CME Credit™ from articles, audio, Clinical Challenges and more. Learn more about CME/MOC

Article Information

Corresponding Author: Emanuela Palmerini, MD, Medical Oncology, Istituto Ortopedico Rizzoli, Department of Experimental, Diagnostic and Specialty Medicine, Bologna University, Via Pupilli 1, 40136 Bologna, Italy (emanuela.palmerini3@unibo.it).

Published Online: May 24, 2018. doi:10.1001/jamaoncol.2018.1120

Conflict of Interest Disclosures: Drs Palmerini and Staals reported serving on an advisory board for Daiichi Sankyo. No other disclosures were reported.

References
1.
Fletcher  CDM, Bridge JA, Hogendoorn PCW, Mertens F, eds.  WHO Classification of Tumours of Soft Tissue and Bone. 4th ed. Lyon, France: IARC Press; 2013:306-309.
2.
Somerhausen Nde  S, van de Rijn  M. Tenosynovial giant cell tumour, diffuse type. In: Fletcher  CDM, Bridge  JA, Hogendoorn  PCW, Mertens  F, eds.  WHO Classification of Tumours of Soft Tissue and Bone. 4th ed. Lyon, France: IARC Press; 2013:102-103.
3.
Palmerini  E, Staals  EL, Maki  RG,  et al.  Tenosynovial giant cell tumour/pigmented villonodular synovitis: outcome of 294 patients before the era of kinase inhibitors.  Eur J Cancer. 2015;51(2):210-217.PubMedGoogle ScholarCrossref
4.
Murphey  MD, Rhee  JH, Lewis  RB, Fanburg-Smith  JC, Flemming  DJ, Walker  EA.  Pigmented villonodular synovitis: radiologic-pathologic correlation.  Radiographics. 2008;28(5):1493-1518.PubMedGoogle ScholarCrossref
5.
Broski  SM, Murdoch  NM, Skinner  JA, Wenger  DE.  Pigmented villonodular synovitis: potential pitfall on oncologic 18F-FDG PET/CT.  Clin Nucl Med. 2016;41(1):e24-e31.PubMedGoogle ScholarCrossref
6.
Chang  KJ, Byun  BH, Moon  HS,  et al.  Tenosynovial giant cell tumor of diffuse type mimicking bony metastasis detected on F-18 FDG PET/CT.  Nucl Med Mol Imaging. 2014;48(3):230-232.PubMedGoogle ScholarCrossref
7.
Kitapci  MT, Coleman  RE.  Incidental detection of pigmented villonodular synovitis on FDG PET.  Clin Nucl Med. 2003;28(8):668-669.PubMedGoogle Scholar
8.
Staals  EL, Ferrari  S, Donati  DM, Palmerini  E.  Diffuse-type tenosynovial giant cell tumour: current treatment concepts and future perspectives.  Eur J Cancer. 2016;63:34-40.PubMedGoogle ScholarCrossref
9.
Cassier  PA, Gelderblom  H, Stacchiotti  S,  et al.  Efficacy of imatinib mesylate for the treatment of locally advanced and/or metastatic tenosynovial giant cell tumor/pigmented villonodular synovitis.  Cancer. 2012;118(6):1649-1655.PubMedGoogle ScholarCrossref
10.
Tap  WD, Wainberg  ZA, Anthony  SP,  et al.  Structure-guided blockade of CSF1R kinase in tenosynovial giant-cell tumor.  N Engl J Med. 2015;373(5):428-437.PubMedGoogle ScholarCrossref
If you are not a JN Learning subscriber, you can either:
Subscribe to JN Learning for one year
Buy this activity
jn-learning_Modal_LoginSubscribe_Purchase
Close
If you are not a JN Learning subscriber, you can either:
Subscribe to JN Learning for one year
Buy this activity
jn-learning_Modal_LoginSubscribe_Purchase
Close
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right
Close

Name Your Search

Save Search
Close
With a personal account, you can:
  • Track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
jn-learning_Modal_SaveSearch_NoAccess_Purchase
Close

Lookup An Activity

or

Close

My Saved Searches

You currently have no searches saved.

Close
With a personal account, you can:
  • Access free activities and track your credits
  • Personalize content alerts
  • Customize your interests
  • Fully personalize your learning experience
Education Center Collection Sign In Modal Right
Close