68Ga-PSMA-HBED-CC PET/CT Findings in a Patient of Polyostotic Fibrous Dysplasia.

ABSTRACT: A 43-year-old man diagnosed with fibrous dysplasia with McCune-Albright syndrome was subjected to 18F-fluoride bone scan and 68Ga-PSMA-HBED-CC PET/CT as per the institution protocol. 18F-bone scan revealed extensive involvement of axial and appendicular skeleton confirming polyostotic fibrous dysplasia. 68Ga-PSMA PET/CT showed increased tracer uptake in corresponding lesions of fibrous dysplasia. PSMA uptake in fibrous dysplasia lesions has been rarely described with literature evidence being limited to anecdotal case reports. Nevertheless, due to increasing use of PSMA PET/CT, one should be aware of this false-positive finding to avoid misinterpretation of the scans.

Bilateral adrenal metastases and metastatic subcutaneous deposit in the chest wall from osteosarcoma of the mandible: utility of 18F-FDG-PET.

Adrenal gland involvement as well as metastatic subcutaneous nodule from skeletal osteosarcoma are two extremely rare and unusual manifestations in the natural history of the disease. We herein report a 45 yr old female with both these uncommon occurrences, having large bilateral adrenal metastases and a metastatic subcutaneous nodule in fluorine-18 fluorodesoxy glucose- positron emission tomography the chest wall along with pulmonary metastasis arising from osteosarcoma of the mandible. Our (18)F-FDG-PET study provided all information needed about the disease status in a single examination. It is noteworthy that osteosarcoma of the jaws, thought to be relatively less aggressive compared to its counterpart in long bones, can occasionally give rise to widespread metastases, including atypical sites. A systematic review of the existing literature aiming to explore the patients' characteristics and clinical behavior of adrenal metastases from osteosarcoma, including the present case, was carried out. This was nearly always associated with pulmonary metastases with occasional association with brain or skeletal metastases. Peripheral long bones were the overwhelmingly common site of the primary, the present one being the first report of jaw bone being the primary site, giving rise to adrenal metastases. No age predilection was observed with male to female ratio of 3:1 in the small number of reported cases.

Bronchoalveolar carcinoma of lung masquerading as iodine avid metastasis in a patient with minimally invasive follicular carcinoma of thyroid.

A 52-year-old man with follicular thyroid carcinoma was administered 182 mCi of radioiodine (I-131) a month after total thyroidectomy. Post-therapy scan revealed diffuse uptake of radioiodine in the apical left lung. CT-guided biopsy of this mass revealed mucinous bronchoalveolar carcinoma. Immunohistochemistry for thyroglobulin was negative. An FDG PET scan showed avid uptake in the lung mass. Surgery was ruled out, so he was given chemotherapy, without benefit. The lesion continued to show I-131 uptake even while on daily T3 substitution, suggesting that the mass was thyroid stimulating hormone-independent. Because the mass showed I-131 uptake and chemotherapy was not beneficial, it was decided to treat with I-131. He was continued on T3 substitution therapy and was given 209 mCi of I-131. Follow-up CT scan a few weeks later reported a 1-cm all round reduction of the mass. I-131 scan showed avid tracer uptake in the mass. This case suggests the possibility of this therapeutic option in nonthyroidal tumors that may concentrate radioiodine.