MyPACS.net: Radiology Teaching Files > Case 48318818

Last visited 11/29/2010 TIBIAL SCLEROTIC LESION
Contributed by: Aaron Betts, Resident, Brooke Army Medical Center, Texas, USA.
Patient: 19 year old female
History: 19 year old female: with anterior right knee pain over the tibial tuberosity.
Images:[small]larger

Fig. 1: AP view of the right knee. Sclerotic region of medial tibial metadiaphysis containing foci of internal relative lucency.

Fig. 2: Limited Tc-99m MDP whole body bone scan, anterior. Increased radiotracer uptake in the right tibial tuberosity. No increased radiotracer activity to correspond to sclerotic lesion on radiograph.

Fig. 3: Limited Tc-99m MDP whole body bone scan, anterior. No increased radiotracer activity to correspond to sclerotic lesion on radiograph.

Fig. 4: Spot lateral view from Tc-99m MDP bone scan again demonstrates focus of increased radiotracer activity in the right tibia tuberosity. No increased radiotracer activity to correspond to sclerotic lesion on radiograph. Mild stress-related changes of the right knee are incidentally noted.
Findings:
  • Well circumscribed region of sclerosis measuring 3.1 cm
  • Well circumscribed lucent focus within the lesion.
  • No associated periosteal reaction or soft tissue mass.
  • Normal appearance of the tibial tuberosity.

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Diagnosis:
  • Non-ossifying fibroma, partially ossified
  • Osgood-Schlatter disease involving the right tibial tuberosity
Discussion:

Fibroxanthomas are common lytic osseous lesions of childhood. Fibroxanthomas can be divided into two different entities: fibrous cortical defect (FCD) or non-ossifying fibroma (NOF). These lesions are histologically identical, consisting of whorled bundles of connective tissue. FCDs are typically smaller, and seen in younger children, whereas NOFs are slightly larger, and more common in adolescents and young adults. They are usually asymptomatic, but may occasionally cause pain. They will usually regress over time, and occasionlly will undergo ossification and become sclerotic during this regression. On Tc-99m MDP bone scan, active fibroxanthomas will demonstrate increased radiotracer uptake. However, involuting lesions will not take up radiotracer.

 

In this case, the sclerotic appearance and location of the lesion was suggestive of on ossified NOF. However, the lucent foci suggested that the lesion could be an incompletely ossified NOF verus osteoid osteoma with a lucent central nidus. Bone scan was recommeded to help differentiate an involuting NOF from an active osteoid osteoma.

References:
  1. Helms, CA. Fundamentals of Skeletal Radiology, Third Edition. Elsevier Saunders, Philadelphia 2005.
  2. Weissleder R, Wittenberg J, Harisinghani MG, Chen JW. Primer of Diagnostic Imaging, Fourth Edition. Mosby Elsevier, Philadelphia 2007.

 

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Additional Details:

Case Number: 48318818Last Updated: 2011-12-27
Anatomy: Skeletal System   Pathology: Other
Modality: Conventional Radiograph, Nuc MedAccess Level: Readable by all users

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