Normal Parathyroid Glands Are Most Often Seen on Neck Ultrasound.

RATIONALE AND OBJECTIVES: The dogma is that normal parathyroid glands (PTGs) are not visible on ultrasound (US). Recently, several studies have shown that PTGs present these US features: ovoid structure, homogeneous and hyperechoic. The primary objective was to assess the detection rate, standard size and locations of normal PTGs in a population of patients consulting for thyroid US exam. The secondary objective was to determine if the presence of a goiter or a thyroiditis could modify the visualization of normal PTGs. METHOD: Single-center prospective study on 192 patients based on the typical US appearance previously described to identify one or more PTGs. RESULTS: One or more PTGs were visualized in 75% of patients (144/192). They were visualized preferentially at the lower pole of the thyroid gland and in the infra-thyroid region (66%). The mean (± SD) size of normal PTGs was 5.68 mm (± 1,42 mm)×4.05 mm (± 1,03 mm)×2,68 mm (± 0,61 mm) and mean volume was 33.3 mm3 (± 17.75 mm3). The presence of a goiter made the search for PTGs more difficult whereas the presence of thyroiditis facilitated it. CONCLUSION: The US detection rate of PTGs is high (75%). The identification of PTGs could be particularly useful in the preoperative assessment before total thyroidectomy or parathyroid surgery. It could reduce the risk of postoperative hypoparathyroidism and improve the accuracy of postoperative US surveillance of thyroid cancer. Better knowledge of the usual anatomical location of normal PTGs could also enable better detection of abnormal glands.

Indications for radioiodine administration in follicular-derived thyroid cancer.

Indications for radioiodine administration after thyroid cancer surgery have shifted in recent years toward personalized management, adapted to the individual risk of tumor progression. The most recent guidelines and studies favor de-escalation in indications for administration, dosage and means of preparation with exogenous recombinant TSH stimulation as treatment of choice. Radioiodine administration has 3 possible objectives: • ablation of normal thyroid tissue remnants in patients with low risk of progression, using low radioiodine activity levels, with the advantage of completing disease staging on whole-body scintigraphy performed after administration of the radioiodine capsule, and of facilitating follow-up by thyroglobulin assay; • adjuvant treatment for suspected microscopic metastases in patients with intermediate or high risk of progression, using higher activity levels, with the theoretic aim of limiting recurrence and mortality; • curative treatment in high-risk patients with proven metastases, using exclusively high activity levels, with a view to improving specific survival. In future, indications for ablation and/or activity prescription may be governed by an algorithm incorporating individual baseline progression risk (essentially founded of pTNM staging) and postoperative data such as thyroglobulin level and neck ultrasound results.

Management of adrenal incidentaloma.

Improvements in medical imaging have resulted in the incidental discovery of many silent and unrecognized adrenal tumors. The term "adrenal incidentaloma" (AI) is applied to any adrenal mass≥1cm in its longest axis that is discovered incidentally during abdominal imaging that was not performed to specifically evaluate adrenal pathology. These incidentalomas may be either secretory or non-secretory, benign or malignant. Distinctive characteristics of these lesions must be determined by the clinician to determine appropriate management. Such distinctions are based on laboratory findings and imaging, principally CT with and without contrast injection. Investigations must be carefully chosen to avoid ordering unnecessary and expensive tests for too many patients while, at the same time, avoiding the risk of failing to diagnose a secreting malignant or tumor. These examinations will determine patient care: surgery or surveillance. When simple surveillance is chosen, specific criteria must be met with regard to diagnostic modalities (clinical, imaging, laboratory testing) and its duration.

Limited value of 18F-F-DOPA PET to localize pancreatic insulin-secreting tumors in adults with hyperinsulinemic hypoglycemia.

CONTEXT: Fluorine-18-L-dihydroxyphenylalanine positron emission tomography (18F-FDOPA PET) imaging is increasingly used in the workup of neuroendocrine tumors. It has been shown to be an accurate tool in the diagnosis of congenital hyperinsulinism, but limited information is available on its value in adult disease. OBJECTIVE, PATIENTS, AND DESIGN: The objective of this study was to review our experience with 18F-FDOPA PET imaging in six consecutive patients with hyperinsulinemic hypoglycemia (HH) (four solitary insulinomas, one diffuse beta-cell hyperplasia, one malignant insulinoma). 18F-FDOPA uptake was also evaluated in 37 patients (43 procedures) without HH or other pancreatic neuroendocrine tumors, which acted as a control group. RESULTS: Using visual analysis, 18F-FDOPA-PET proved positive in only one case (a multiple endocrine neoplasia type 1 related insulinoma). In diffuse beta-cell hyperplasia, the pancreatic uptake was similar to controls. In the patient with liver metastases, the extent of disease was underestimated. The pancreatic uptake was not statistically different between controls and hyperinsulinemic patients. The main limitation for identifying insulinomas or beta-cell hyperplasia in adults appears to be to the 18F-FDOPA uptake and retention in the whole pancreas. This drawback is potentially circumvented in focal hyperplasia in newborns due to a lower aromatic amino acid decarboxylase expression in the extralesional pancreatic parenchyma. CONCLUSIONS: 18F-FDOPA PET is of limited value in localizing pancreatic insulin secreting tumors in adult HH. Our results contrast with the referential study and require further analysis.

Incidental diagnosis of struma ovarii after thyroidectomy for thyroid cancer: functional imaging studies and follow-up.

BACKGROUND: Struma ovarii is a rare ovarian germ-cell tumor containing thyroid tissue. We report an unusual case of incidental diagnosis of struma ovarii after thyroidectomy for thyroid cancer. CASE: A 24-year-old woman presented with a papillary thyroid carcinoma (pT3N1). After (131)I administration for thyroid remnant ablation, whole-body scan showed a thyroid bed uptake and a right pelvic uptake corresponding to an ovarian cyst on ultrasonography. Preablation thyroglobulin was more elevated than usually found after total thyroidectomy. (18)F-FDG PET was normal. Histopathological analysis revealed a benign struma ovarii. At 6 months, after oophorectomy, serum-stimulated Tg returned to undetectable value and diagnostic WBS was negative. CONCLUSION: Only few cases of incidental scintigraphic diagnosis of struma ovarii have been described. To our knowledge, it is the first case revealed after remnant ablation for thyroid carcinoma. The distinction with ovarian metastasis is discussed.