Incidental finding of metastatic papillary thyroid carcinoma in a patient with primary hyperparathyroidism.

OBJECTIVE: To report on the management of a patient with the rare concurrence of primary hyperparathyroidism and incidentally found metastatic papillary thyroid carcinoma in an adjacent lymph node. METHODS: We present a case report, including scintigraphic and histologic documentation, and a summary of the related literature. RESULTS: Primary hyperparathyroidism with concomitant occurrence of nonmedullary thyroid carcinoma is rare, occurring in less than 4% of patients. We report a case of a 53-year-old woman with no prior history of endocrine disease with primary hyperparathyroidism and an incidental finding of a concurrent thyroid carcinoma. In this patient, technetium 99m scintigraphy revealed a parathyroid adenoma beneath the inferior pole of the left thyroid bed. Parathyroidectomy was performed successfully with no complications. The final pathology examination showed a large parathyroid adenoma with an incidental finding of a small adjacent lymph node containing metastatic papillary thyroid carcinoma. The patient subsequently underwent total thyroidectomy, and the pathology evaluation revealed papillary thyroid carcinoma, follicular variant. CONCLUSION: To our knowledge, this case of concomitant primary hyperparathyroidism and papillary thyroid cancer is unique in the way in which the diagnosis of metastatic papillary thyroid cancer was made. The presence of parathyroid adenoma should not exclude the diagnosis of thyroid carcinoma; therefore, careful thyroid evaluation should be considered for all patients with primary hyperparathyroidism.

Evaluation of metastatic meningioma with 2-deoxy-2-[18F]fluoro-D-glucose PET/CT.

PURPOSE: The purpose of this study was to characterize the 2-deoxy-2-[18F]fluoro-D-glucose (FDG) PET/CT imaging findings of sacral metastatic meningioma. MATERIALS AND METHODS: An 18-year-old woman with a history of metastatic meningioma, who presented with intractable pain and spasm of the right lower extremity, underwent FDG PET/CT imaging. RESULTS: FDG PET/CT scan demonstrated a moderately hypermetabolic sacral mass. The biopsy of the lesion was consistent with a high-grade malignant meningioma. CONCLUSIONS: Although meningioma is typically a benign tumor, in rare instances, it metastasizes. The current case example exhibits moderately increased metabolism despite findings of high-grade malignancy on biopsy.

Whole-body radiation dosimetry of 2-[18F]Fluoro-A-85380 in human PET imaging studies.

2-[18F]Fluoro-A-85380 (2-[18F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine, 2-[18F]FA) is a recently developed PET radioligand for noninvasive imaging of nicotinic acetylcholine receptors. Previous radiation absorbed dose estimates for 2-[18F]FA were limited to evaluation of activity in only several critical organs. Here, we performed 2-[18F]FA radiation dosimetry studies on two healthy human volunteers to obtain data for all important body organs. Intravenous injection of 2.9 MBq/kg of 2-[18F]FA was followed by dynamic PET imaging. Regions of interest were placed over images of each organ to generate time-activity curves, from which we computed residence times. Radiation absorbed doses were calculated from the residence times using the MIRDOSE 3.0 program (version 3.0, ORISE, Oak Ridge, TN). The urinary bladder wall receives the highest radiation absorbed dose (0.153 mGy/MBq, 0.566 rad/mCi, for a 2.4-h voiding interval), followed by the liver (0.0496 mGy/MBq, 0.184 rad/mCi) and the kidneys (0.0470 mGy/MBq, 0.174 rad/mCi). The mean effective dose equivalent is estimated to be 0.0278 mSv/MBq (0.103 rem/mCi), indicating that radiation dosimetry associated with 2-[18F]FA is within acceptable limits.

The role of 2-deoxy-2-[(18)F]fluoro-D-glucose positron emission tomography/computed tomography in monitoring the immunosuppressive therapy response of inflammatory myofibroblastic tumor.

PURPOSE: To compare the pre and post treatment 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) imaging findings of an inflammatory myofibroblastic tumor (IMT) with its clinical response to immunosuppressive therapy. PROCEDURE: Forty-nine-year-old female presented with dyspnea, chest pain, and weight loss and underwent an FDG-PET/CT scan before and after mediastinal biopsy and treatment with dexamethasone and thalidomide. RESULTS: FDG-PET/CT scan demonstrated a hypermetabolic mediastinal mass. The biopsy of the lesion was consistent with IMT. Following immunosuppressive therapy, the patient's clinical findings resolved, and PET/CT showed a significant decrease in the FDG uptake and the size of the mass. CONCLUSION: Pre-treatment imaging features and post-treatment imaging characteristics of IMT correlate with clinical findings and suggest that FDG-PET/CT may be useful as an adjunct to clinical evaluation in monitoring of immunosuppressive therapy of IMT.