Metabolic and functional imaging employment in the differentiation of brown tumors from bone metastases in a case of primary papillary thyroid cancer and parathyroid adenoma: case report

Journal of the Egyptian National Cancer Institute

Table 1 Summary of the main nuclear imaging findings and the assumptive diagnosis

Imaging modality	Findings	Assumptive diagnosis	Definitive diagnosis (pathology)
Whole-body iodine scan	Negative for any RAI-avid lesions
^99mTechnetium sestamibi	^99mTechnetium sestamibi-avid right supraclavicular and mediastinal lesions	Ectopic parathyroid adenomas	Ectopic mediastinal parathyroid adenoma and metastatic papillary thyroid carcinoma of the right supraclavicular lymph node
Whole-body ¹⁸F-FDG PET/CT scan	FDG-avid right supraclavicular lymph node as well as multiple lytic bone lesions with diffusely increased bone marrow metabolic activity in the axial and peripheral skeleton	The right supraclavicular lymph node appears metabolically active but non-RAI-avid suggesting a possibility of having dedifferentiated features of the metastatic thyroid lesions. The ^99mTc MIBI-avid superior mediastinal lesion was non-FDG-avid raising a possibility of ectopic parathyroid mass with multiple brown tumors	The mediastinal lesion: ectopic parathyroid adenoma The right supraclavicular lymph node: metastatic papillary thyroid carcinoma
Postoperative follow-up whole-body ¹⁸F-FDG PET/CT scan	Complete metabolic resolution of all the previous FDG-avid skeletal lesions with some sclerotic changes	Supporting the previous assumption of ectopic parathyroid mass with multiple brown tumors