Findings
The original MRI shows a mass of the distal radius which extends to the end of the bone. There is expansion of the distal radius with the mass penetrating through the bone particularly slightly into the dorsal soft tissue. There is a suggestion of subtle fluid levels of the mass on the T2 axial image. Resection was performed with a fibular autograft utilized for wrist fusion. Subsequent imaging demonstrates multiple soft tissue masses with faint, peripheral calcification. On MRI, the masses are similar in appearance to the original mass of the distal radius.
Diagnosis: Soft Tissue Recurrence of Giant Cell Tumor of Bone
Giant cell tumor of bone is a fairly aggressive although most frequently benign process (malignancy can only be assessed via pathology). The preoperative study is typical with an end of the bone lesion in a relatively young patient with expansion of the bone and somewhat aggressive characteristics. Treatment can be done by curettage and bone grafting/packing or as in this case with resection and limb reconstruction. One of the rare postoperative situations is soft tissue recurrence. Although not completely understood, it is thought to be related to soft tissue contamination at the time of surgery to treat the lesion. The very low occurrence of this process makes conclusions somewhat limited in their value; however, the soft tissue recurrence is perhaps more prominent when the lesion already extends into the soft tissue. Additionally, treatment with curettage as compared to resection does appear to have an increased risk of soft tissue recurrence.
The soft tissue masses of recurrence of giant cell tumor of bone often do have a peripheral, thin rim of calcification or less commonly, dense, central calcification (lesions without calcification still tend to predominate). This is particularly interesting given the extremely uncommon scenario of mineralization of a native giant cell tumor of bone. Postoperative radiographs showing soft tissue mineralization in these patients should raise suspicion for soft tissue recurrence. This patient was originally treated at an outside, international center and came to our institution for the treatment of his soft tissue masses. The patient is currently undergoing denosumab treatment to help decrease the size of the masses and mineralize the masses to aid in making their resection easier.
References
Xu L, Jin J, Hu A, Xiong J, Wang D, Sun Q, Wang S. Soft tissue recurrence of giant cell tumor of the bone: Prevalence and radiographic features. J Bone Oncol. 2017 Sep 20;9:10-14. doi: 10.1016/j.jbo.2017.09.002. PMID: 29018768; PMCID: PMC5626916.
Xiang, F.; Liu, H.; Deng, J.; Ma, W.; Chen, Y. Progress on Denosumab Use in Giant Cell Tumor of Bone: Dose and Duration of Therapy. Cancers 2022, 14, 5758. https://doi.org/10.3390/cancers14235758