fluorocholine and Carcinoma--Neuroendocrine

A 66-year-old man with prostate cancer underwent F-fluorocholine PET/CT and thereafter Ga-labeled prostate-specific membrane antigen PET/CT to explore a rising prostate-specific antigen level. Both PET/CT studies showed a thyroid incidentaloma of the right lobe. Neck ultrasound confirmed the presence of a 16-mm right thyroid nodule. The serum calcitonin level was moderately increased at 25 ng/mL (<10). Cytology was non-diagnostic (Bethesda I). A right lobectomy was performed and pathology revealed a 15-mm medullary thyroid cancer. Two months after surgery, the calcitonin level returned to normal at 3.3 ng/mL.

Topics: Aged; Carcinoma, Neuroendocrine; Choline; Edetic Acid; Gallium Isotopes; Gallium Radioisotopes; Humans; Incidental Findings; Male; Oligopeptides; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Thyroid Neoplasms

A 70-year-old man with prostate cancer and increased prostate-specific antigen level of 55 ng/mL underwent staging F-fluorocholine PET/CT, which demonstrated the primary prostate tumor and a focal area corresponding to a 2-cm hypodense nodule in the left thyroid lobe. Fine-needle aspiration and subsequent total thyroidectomy with central lymph node dissection showed an oxyphilic papillary thyroid carcinoma and a medullary microcarcinoma. Oxyphilic tumors represent a significant proportion of the few case reports of incidental focal thyroid fluorocholine thyroid uptake.

Topics: Aged; Biopsy, Fine-Needle; Carcinoma; Carcinoma, Neuroendocrine; Carcinoma, Papillary; Choline; Humans; Incidental Findings; Male; Neck Dissection; Positron Emission Tomography Computed Tomography; Prostate-Specific Antigen; Prostatic Neoplasms; Radiopharmaceuticals; Thyroid Cancer, Papillary; Thyroid Neoplasms; Thyroidectomy