Long-Term Control of Hypercortisolism by Vandetanib in a Case of Medullary Thyroid Carcinoma with a Somatic RET Mutation.

BACKGROUND: Medullary thyroid carcinomas (MTCs) complicated by ectopic Cushing's syndrome (CS) have a poor prognosis, partially due to the difficulty in controlling hypercortisolism by adrenal blocking drugs. Recent reports (including the initial follow-up of this patient) have suggested that tyrosine kinase inhibitors (TKIs) may be a therapeutic option due to an anti-secretory action on ACTH. However, there is a lack of long-term follow-up studies. PATIENT FINDINGS: The case is reported of a 58-year-old man with MTC-related CS resistant to a combination of several anti-cortisolic drugs. Vandetanib, an oral multi-TKI that targets RET in particular, was initiated, and a rapid reversal of the hypercortisolism was observed without any change in tumor size. Vandetanib was briefly interrupted twice, once for 45 days because of side effects and a second time for 10 days to schedule surgical debulking. Each time, plasma cortisol and calcitonin levels increased after TKI withdrawal and were rapidly lowered by vandetanib reintroduction. As described in other cases of CS caused by MTC, a marked ACTH increase after desmopressin stimulation was observed before vandetanib therapy. In contrast, a blunted ACTH response to desmopressin was documented throughout the course of vandetanib treatment. This modulation of the tumoral ACTH production is a strong argument in favor of a TKI anti-secretory action. A left thyroid lobectomy and a modified neck dissection were performed one year after the initiation of vandetanib in order to reduce the tumor mass. An activating M918T RET (c.2753T>C) somatic mutation was identified in a lymph node metastasis. CONCLUSION: Three years and eight months after vandetanib initiation, there was no sign of recurrence of hypercortisolism. This case illustrates the long-term effectiveness of vandetanib in maintaining the control of hypercortisolism in MTC-related CS.

Prospective evaluation of thyroid imaging reporting and data system on 4550 nodules with and without elastography.

OBJECTIVE: To evaluate prospectively the diagnostic accuracy of the thyroid imaging reporting and data system (TI-RADS) and its interobserver agreement and to estimate the reduction of indications of fine-needle aspiration biopsies (FNABs). DESIGN: A prospective comparative study was designed. METHODS: In 2 years, 4550 nodules in 3543 patients were prospectively scored using a flowchart and a six-point scale and then submitted to US-FNAB. Results were read according to the Bethesda system. Histopathological results were available for 263 cases after surgery. Sensitivity, specificity, negative predictive value (NPV) and positive predictive value, and accuracy were calculated for the gray-scale score, elastography, and a combination of both methods. Interobserver agreement was calculated using the kappa statistic. The reduction in the number of FNABs was estimated. RESULTS: When compared with cytopathological results, sensitivity, specificity, NPV, and accuracy were 95.7, 61, 99.7, and 62% for the TI-RADS gray-scale score; 74.2, 91.1, 98, and 90% for elastography; and 98.5, 44.7, 99.8, and 48.3% for a combination of both methods respectively. When compared with histopathological results, the sensitivity of the gray-scale score, elastography, and a combination of both methods were 93.2, 41.9, and 96.7% respectively. Interobserver agreement for the six-point scale and the recommendation for biopsy were substantial (κ value=0.72 and 0.76 respectively). The reduction in the number of FNABs was estimated to be 33.8%. CONCLUSION: The TI-RADS score has high sensitivity and NPV for the diagnosis of thyroid carcinoma. A hard nodule should always be considered as suspicious for malignancy but elastography cannot be used alone. Combination of elastography with gray-scale can be used to improve sensitivity or specificity. Interobserver agreement and decrease in unnecessary biopsies are significant.

Outpatient thyroid remnant ablation using repeated low 131-iodine activities (740 MBq/20 mCix2) in patients with low-risk differentiated thyroid cancer.

CONTEXT: In low-risk differentiated thyroid cancer (DTC), postoperative (131)I remnant ablation should employ a minimum effective activity; reports increasingly suggest efficacy of low activities, e.g. 1110 MBq/30 mCi. OBJECTIVES, DESIGN, PATIENTS, AND INTERVENTIONS: We retrospectively studied the ablation capability and diagnostic utility of the Minidose protocol, two 740-MBq/20 mCi outpatient administrations, 6-18 months apart, plus related diagnostic procedures, in 160 consecutive (near-) totally thyroidectomized low-risk DTC (pT1/N0-Nx) patients. Successful ablation comprised negative 740-MBq whole-body scintigraphy with cervical uptake below 0.1%, negative stimulated thyroglobulin (STg) (<1 ng/ml, negative thyroglobulin antibodies), and negative Doppler ultrasonography (performed around Minidose 2). SETTING: The study took place at a referral center. RESULTS: Minidose imaging found unsuspected nodal or distant metastases in nine of 160 patients (5.6%). Ablation success rates after one (two) 740-MBq activity (activites) were 75.9% (90.2%) in 145 (132) evaluable imaging-negative patients. Compared with thyroid hormone withdrawal, recombinant human TSH stimulation was associated with higher urinary iodine excretion/creatinine, lower cervical uptake, and more frequent ablation success after the first 740 MBq; success rates no longer differed significantly after both administrations. Patients with STg below 10 ng/ml at Minidose 1 were oftener ablated at Minidose 2 (odds ratio=13.9, 95% confidence interval=2.5-76.4, P<0.003), attaining 92.0% final ablation success after recombinant human TSH preparation, suggesting that one 740-MBq activity should suffice in this subgroup. All 81 evaluable patients with prolonged follow-up (mean 41.8±21.9 months after Minidose 1) had no evidence of disease at the last visit. CONCLUSIONS: The Minidose outpatient ablation protocol is effective and diagnostically useful in low-risk DTC.

Pregnancy does not accelerate corticotroph tumor progression in Nelson's syndrome.

CONTEXT: Pituitary surgery is the first line of treatment for Cushing's disease; when surgery fails, bilateral adrenalectomy may be proposed, particularly for women with a desire for pregnancy. Little is known about the impact of pregnancy on corticotroph tumor progression after bilateral adrenalectomy. OBJECTIVE: The aim was to evaluate the impact of pregnancy on corticotroph tumor progression after bilateral adrenalectomy in Cushing's disease and to assess maternal and pregnancy outcomes. DESIGN: We conducted a retrospective cohort study. SETTING: Patients who became pregnant after bilateral adrenalectomy were followed in a single center. PATIENTS: Twenty pregnancies from 11 patients with Cushing's disease were treated by bilateral adrenalectomy and no pituitary irradiation. MEASUREMENTS: Corticotroph tumor progression was assessed by serial pituitary magnetic resonance imaging and plasma ACTH measurements before, during, and after pregnancy. Comparisons were performed using paired Wilcoxon rank tests. Data on maternal and neonatal outcomes were recorded by correspondence from patients and obstetricians. RESULTS: Corticotroph tumor progression occurred in eight of 17 pregnancies, and ACTH increased in eight of 10 pregnancies. However, rates of increase during or after pregnancy were not faster than those observed before pregnancy. Maternal complications occurred in four pregnancies from two patients, including gestational hypertension in three and gestational diabetes mellitus in three. Among these four pregnancies, three had a favorable outcome, and one led to an in utero death after eclampsia, due to loss to follow-up. No other maternal or fetal complications were reported. CONCLUSION: Pregnancy does not accelerate corticotroph tumor progression after bilateral adrenalectomy. Pregnancy is manageable, provided the patients can be followed closely.