Coexisting iodine avid and iodine nonconcentrating lesions with multiple distant soft tissue metastasis in papillary thyroid cancer
A 42-year-old male patient with a history of total thyroidectomy and bilateral cervical nodal dissection positive for papillary carcinoma thyroid was referred to our department for a follow positron emission tomography-computed tomography (PET-CT) scan for evaluation of lung nodules and muscle lesions that he developed five years after primary treatment. During the follow-up, prompted by elevated thyroglobulin levels, an iodine-131 whole body scan and single photon emission tomography-computed tomography (SPECT-CT) [] showed positive lesions, one in the liver and another in the left gluteal region. The gluteal region was positive for metastatic papillary carcinoma thyroid on biopsy. A fludeoxyglucose (FDG) PET-CT scan [] was done to find more lesions and revealed metabolically active lesions in liver segment VI [] and the left gluteus and a new paraspinal muscle lesion at the nape of the neck [], whereas the lung nodules were metabolically inactive []. A post-therapy scan [] at a therapeutic dose of 200 mci of iodine-131 revealed iodine concentration in the liver and a gluteal lesion, whereas there was no concentration in lung nodules and neck lesion. The present FDG PET CT scan [] as a response evaluation six month post treatment revealed a metabolic response in the liver and gluteal lesion [], but an increasing size of the neck lesion [] and lung nodules []. Presently, the patient is put on redifferentiation therapy with sorafenib and suppressive doses of thyroxin.