Thyroid function tests, incongruent internally and with thyroid status, both in a pregnant woman and in her newborn daughter

Introduction

Thyroid function tests (TFT) are extensively used in daily clinical practice. Here, we described a case of incongruent TFT both in a pregnant woman and in her newborn.

Case presentation

A 32-year-old woman, diagnosed with autoimmune thyroiditis during her first pregnancy, was monitored during her second gestation. At week 5 + 2 days, thyroid-stimulating hormone (TSH) and free thyroxine (FT4) values (Dimension VISTA 1500, Siemens Healthineers) were within normal limits. At week 19 + 5 days, TSH remained normal while FT4 increased approximately by three-fold. FT4 inconsistency was with both TSH and the clinical status since she continued to be clinically euthyroid. On the same serum sample, thyroid autoantibodies were negative. At week 25 + 4 days, the patient complained of palpitations and dyspnea, with tachycardia. Even though TSH was normal, high levels of both FT4 and free triiodothyronine (FT3) were interpreted as evidence of thyroid overactivity and methimazole was started. TFT of the pregnant woman continued to be monitored throughout gestation. Postpartum FT4 and FT3 gradually returned to normal. TFT, performed on the daughter's serum, 3 days after birth, showed the same inconsistency as her mother but without clinical signs of congenital hyperthyroidism. Based on the clinical and laboratory setting, the presence of circulating autoantibodies against T3 and T4 (THAb) was suspected and demonstrated by radioimmunoprecipitation.

Conclusion

Analytical interferences should be supposed when TFT do not fit with the clinical picture and despite their infrequency, THAb must also be considered. To our knowledge, this is the first case describing the passage of THAb to the newborn.

A Retrospective Cohort Study of Histology-Proven Neuroendocrine Neoplasms in the Italian Area of Udine

AIMS

The aim of this study was to investigate the epidemiology of histology-proven Neuroendocrine neoplasms (NENs) in an Italian area.

BACKGROUND

NENs are a rare and poorly known disease and the global incidence and prevalence appear to be increasing over the past decades.

OBJECTIVE

The objectives of this study were to estimate the incidence and trends of NENs in a 250,000-inhabitant area in the North-East of Italy in the 1998-2018 period and to compare them with international data.

METHODS

This retrospective cohort study was based on the analysis of anonymous health administrative databases, linked with each other at individual patient level through an anonymous stochastic key. NENs were identified from the anatomical pathology database. The standardized incidence rate (2010ESP and US2000) ± 95% CI per 100,000 were calculated, both annually and globally, for the whole period. Incidence was also calculated for specific anatomical sites and by gender. Trends for the considered periods and sites were summarized through the annual percent change (APC) and average increase (cases per 100,000 per year).

RESULTS

In the 1998-2018 period, the standardized incidence rate of NENs in the area of Udine was 2.49 (APC 3.33). A total of 162 cases were observed (51.2% males). Differences in incidence and trend were observed between sexes. The obtained results were consistent with those reported in other countries, confirming a significant and steady increase in NENs incidence in the last twenty years.

CONCLUSION

This study provides new epidemiological data on NENs in Italy. The observed sex differences deserve further investigations.

An Unusual Case of Medullary Thyroid Carcinoma and A Revision of Current Literature

BACKGROUND

Medullary thyroid cancer (MTC) accounts for 5% of all thyroid cancers and occurs either sporadically or in a hereditary pattern. Routine calcitonin (CT) measurement is suggested for MTC screening in patients with nodular thyroid disease.

PATIENT FINDINGS

A 45 years-old woman incidentally discovered, with neck ultrasound, the presence of thyroid micronodules. Fine-needle aspiration (FNA) on thyroid prevailing nodule did not demonstrate cellular atypia. During follow-up, FNA was repeated on the previously analyzed nodule suspicious for Hürthle cell nodule suspicious for follicular neoplasm and on another hypoechoic right nodule which showed cellular atypia. CT was <2 pg/ml (normal values <18.2 pg/ml), anti-thyroid antibodies were positive and the patient showed a normal thyroid function. The patient also was diagnosed with primary hyperparathyroidism with an enlarged parathyroid gland behind the right thyroid lobe. Therefore, she underwent total thyroidectomy and a selective parathyroidectomy was performed. Histology showed an encapsulated microMTC (pT1aNxMx) associated with diffuse C-cell hyperplasia and lymphocytic thyroiditis. The neoplasm was positive for calcitonin and chromogranin A and negative for thyroglobulin. A right parathyroid adenoma was also diagnosed. One month after surgery basal and stimulated CT were <2 ng/ml. Genetic analysis did not reveal mutation of RET proto-oncogene. Twelve months after surgery, neck ultrasonography, chest and abdomen computed tomography did not demonstrated residual/recurrent disease with undetectable serum CT.

CONCLUSION

In the literature, few MTC cases with normal serum CT have been reported. Although MTC without elevated plasma CT is extremely rare, normal or low CT levels, do not entirely exclude this diagnosis.

Mazabraud's Syndrome: A Case Report and Up-To-Date Literature Review

OBJECTIVE

Mazabraud's syndrome is a rare form of bone fibrous dysplasia associated with intramuscular myxomas. Fibrous dysplasia, is generally localized to pelvis and femur and it results in a fragile bone with deformities, pain, pathological fractures and functional impairment. Intramuscular myxomas, are rare benign mesenchymal neoplasms that exceptionally may evolve to malignant forms.

METHODS

This case report describes a 66-year-old woman with Mazabraud's Syndrome (MS), characterized both by monostotic right femur fibrous dysplasia and by a solitary intramuscular myxoma at the right quadriceps muscle, that underwent a long-term treatment (4 years) with intravenous zoledronic acid.

RESULTS

Zoledronic acid therapy rapidly lowered bone pain together with a reduction of intramuscular myxoma volume, but did not affect the extension of fibrous dysplasia. No adverse effects have been observed during treatment.

CONCLUSION

Highly active bisphosphonates are commonly used for the treatment of bone metabolic disorders and they are generally well tolerated. Zoledronic acid may represent a promising alternative to surgical intervention in MS, although its use in rare form of bone fibrous dysplasias is still controversial.

Clinical presentation and management of patients with primary hyperparathyroidism in Italy

PURPOSE

Evaluation of the phenotype of primary hyperparathyroidism (PHPT), adherence to International Guidelines for parathyroidectomy (PTx), and rate of surgical cure.

METHOD

From January 2014-January 2016, we performed a prospective, multicenter study in patients with newly diagnosed PHPT. Biochemical and instrumental data were collected at baseline and during 1-year follow-up.

RESULTS

Over the first year we enrolled 604 patients (age 61 ± 14 years), mostly women (83%), referred for further evaluation and treatment advice. Five hundred sixty-six patients had sporadic PHPT (93.7%, age 63 ± 13  years), the remaining 38 (6.3%, age 41 ± 17  years) had familial PHPT. The majority of patients (59%) were asymptomatic. Surgery was advised in 281 (46.5%). Follow-up data were available in 345 patients. Eighty-seven of 158 (55.1%) symptomatic patients underwent PTx. Sixty-five (53.7%) of 121 asymptomatic patients with at least one criterion for surgery underwent PTx and 56 (46.3%) were followed without surgery. Negative parathyroid imaging studies predicted a conservative approach [symptomatic PHPT: OR 18.0 (95% CI 4.2-81.0) P < 0.001; asymptomatic PHPT: OR 10.8, (95% CI 3.1-37.15) P < 0.001). PTx was also performed in 16 of 66 (25.7%) asymptomatic patients without surgical criteria. Young age, serum calcium concentration, 24 h urinary calcium, positive parathyroid imaging (either ultrasound or MIBI scan positive in 75% vs. 16.7%, P = 0.001) were predictors of parathyroid surgery. Almost all (94%) of patients were cured by PTx.

CONCLUSIONS

Italian endocrinologists do not follow guidelines for the management of PHPT. Negative parathyroid imaging studies are strong predictors of a non-surgical approach. PTx is successful in almost all patients.

Shift from Levothyroxine Tablets to Liquid Formulation at Breakfast Improves Quality of Life of Hypothyroid Patients

Background: Until recently, treatment of hypothyroidism has been accomplished using monotherapy of synthetic L-thyroxine (L-T4) sodium tablets that should be taken 30-60 minutes before breakfast. Nowadays, a liquid preparation of levothyroxine is available and can effectively replace tablets without the need of waiting before having breakfast. Evidence of Quality of life (QoL) improvement when shifting from the former to the latter preparation, however, is still lacking.

Objective: The study aimed to assess changes in QoL of hypothyroid patients dissatisfied with their therapy with L-T4 sodium tablets who were switched from tablets taken 30-60 minutes before breakfast to liquid L-T4 at breakfast.

Methods: A total of 418 consecutive hypothyroid subjects treated by means of L-T4 tablets were asked about their satisfaction/dissatisfaction in order to take the medication 30-60 minutes before having breakfast. Overall, 110 patients (26.3%) complained of the timing of their L-T4 therapy (30-60 minutes before breakfast). A dedicated QoL questionnaire (ThyTSQ), taking just a few minutes to be filled in was then administered to these dissatisfied patients. They were therefore switched to L-T4 to be taken at breakfast. Aiming to avoid TSH elevation due to L-T4 tablets malabsorption caused by meal interference and gastric pH changes, patients were invited to take L-T4 liquid form, as this is claimed to be scarcely affected by the non-fasting state. The questionnaire (ThyTSQ) was administered again at the control visit 3 months later. TSH, FT4, FT3 serum concentrations and metabolic parameters were also recorded.

Results: An improved QoL, mainly due to an easier adherence to treatment, was reported by 66.6% of 102 patients who completed the study after shifting from taking medication 30-60 minutes before breakfast to at breakfast ingestion (P<0.01). An overall 10.7% of patients found the liquid formulation distasteful. Mean values of TSH, FT4, FT3, and of metabolic parameters did not significantly change but in eight patients (7.7%) who showed a TSH increase > 2mIU/L

Conclusion: In hypothyroid subjects dissatisfied with L-T4 tablets ingested 30-60 minutes before breakfast, the shift to the same dose of L-T4 in liquid form taken at breakfast improved QoL in the majority of patients, without affecting thyroid function.

The use of ultrasensitive thyroglobulin assays reduces but does not abolish the need for TSH stimulation in patients with differentiated thyroid carcinoma

Measurement of serum Tg using ultrasensitive assays is proposed to replace TSH-stimulated Tg measurement in the follow-up of differentiated thyroid cancer (DTC). Aim of our study was to verify this possibility using two ultrasensitive Tg assays. We selected 215 DTC patients with undetectable (<1 ng/ml) basal serum Tg at the time of a recombinant human TSH (rhTSH) stimulation. According to standard criteria, 173 (80.4%) patients were considered free of disease, 17 (7.9%) had documented disease and 25 (11.7%) had no evidence of disease but detectable serum rhTSH-stimulated Tg (biochemical disease). The sera of these patients were re-assayed with two commercial ultrasensitive assays and the results were compared with the clinical data. Basal Access and E-Iason Tg assays were able to distinguish patients with persistent disease or free of disease with a sensitivity of 82.3 and 82.3%, specificity of 85.5 and 86.1%, positive predictive value (PPV) of 35.8 and 36.8%, negative predictive value (NPV) of 98 and 98.6%, respectively. With both assays the addition of neck ultrasound to basal Tg increased the sensitivity and the NPV to 100% and decreased the false negative rate to 0%. In patients with detectable basal Tg without evidence of disease, serum Tg converted from detectable to undetectable in about 80% of the cases during 2-yr follow-up. Our study indicates that the combination of neck ultrasound and basal ultrasensitive Tg allows to identify all patients free of disease and can decrease the need for rhTSH stimulation in nearly 80% of the patients.

Delayed risk stratification, to include the response to initial treatment (surgery and radioiodine ablation), has better outcome predictivity in differentiated thyroid cancer patients

INTRODUCTION

After initial treatment, differentiated thyroid cancer (DTC) patients are stratified as low and high risk based on clinical/pathological features. Recently, a risk stratification based on additional clinical data accumulated during follow-up has been proposed.

OBJECTIVE

To evaluate the predictive value of delayed risk stratification (DRS) obtained at the time of the first diagnostic control (8-12 months after initial treatment).

METHODS

We reviewed 512 patients with DTC whose risk assessment was initially defined according to the American (ATA) and European Thyroid Association (ETA) guidelines. At the time of the first control, 8-12 months after initial treatment, patients were re-stratified according to their clinical status: DRS.

RESULTS

Using DRS, about 50% of ATA/ETA intermediate/high-risk patients moved to DRS low-risk category, while about 10% of ATA/ETA low-risk patients moved to DRS high-risk category. The ability of the DRS to predict the final outcome was superior to that of ATA and ETA. Positive and negative predictive values for both ATA (39.2 and 90.6% respectively) and ETA (38.4 and 91.3% respectively) were significantly lower than that observed with the DRS (72.8 and 96.3% respectively, P<0.05). The observed variance in predicting final outcome was 25.4% for ATA, 19.1% for ETA, and 62.1% for DRS.

CONCLUSIONS

Delaying the risk stratification of DTC patients at a time when the response to surgery and radioiodine ablation is evident allows to better define individual risk and to better modulate the subsequent follow-up.

Medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) accounts for 5-8% of all thyroid cancers. MTC is mainly sporadic in nature, but an hereditary pattern [multiple endocrine neoplasia type 2 (MEN 2)] is present in 20-30% of cases, transmitted as an autosomal-dominant trait due to germline mutations of the RET proto-oncogene. About 98% of patients with MEN 2 have germline mutations in exons 5, 8, 10, 11, 13, 14, 15 or 16 of the RET gene. The primary treatment of both hereditary and sporadic forms of MTC is total thyroidectomy and removal of all neoplastic tissue present in the neck. The therapeutic option for lymph node surgery should be dictated by the results of presurgical evaluation. After total thyroidectomy, measurements of serum calcitonin (CT) and carcinoembryonic antigen are of paramount importance in the postsurgical follow-up of patients with MTC as they reflect the presence of persistent or recurrent disease. Complete remission is demonstrated by undetectable and stimulated serum CT measurement. On the contrary, if serum CT is detectable under basal conditions or becomes detectable after stimulation, the patient is probably not cured, but imaging techniques will not demonstrate any disease until serum CT approaches levels >150 pg/ml. The tumour metastasises early to both paratracheal and lateral cervical lymph nodes. Metastases outside the neck may occur in the liver, lungs, bones and, less frequently, brain and skin. Surgery is the main treatment for local and distant metastases whenever feasible. Systemic chemotherapy with dacarbazine, 5-fluorouracil and doxorubicin (alone or in combination) has shown very limited efficacy, achieving only partial responses in the range of 10-20% and of short duration. Several kinase inhibitors are currently under evaluation and preliminary results are promising. Familial cases must be identified by searching for RET proto-oncogene mutations in the proband and in family members. Carriers of the RET gene are candidates for prophylactic thyroidectomy at different ages depending on the risk associated with the specific RET mutations.

Lack of association between urinary iodine excretion and successful thyroid ablation in thyroid cancer patients

BACKGROUND

Low-iodine diet is prescribed before (131)I administration in patients with differentiated thyroid cancer, although no study has properly quantified its clinical benefit.

OBJECTIVE

Our study aimed to evaluate the association between urinary iodine excretion (UIE) and (131)I ablation by correlating UIE with the rate of successful ablation.

PATIENTS

We retrospectively studied 201 differentiated thyroid cancer patients who had received (131)I therapy and posttherapy whole-body scan (WBS) for remnant ablation after either thyroid hormone withdrawal (THW group, n = 125) or recombinant human TSH (rhTSH group, n = 76). The outcome of thyroid ablation was assessed using two different criteria: no visible uptake at control WBS 8-12 months after ablation or no visible uptake plus undetectable stimulated serum thyroglobulin (Tg).

RESULTS

According to the criterion of no visible uptake, 84.6% of the patients were successfully ablated, with no significant difference between THW and rhTSH groups. Mean UIE at the time of ablation was 132 +/- 160 microg/liter, not significantly different between patients of the THW and rhTSH groups. There was no significant difference in UIE between ablated or nonablated patients both in the whole group and the rhTSH or THW groups. According to the criterion of no visible uptake plus undetectable stimulated serum Tg (in anti-Tg negative patients) at control WBS 8-12 months after ablation, UIE was not significantly different in ablated and nonablated patients.

CONCLUSIONS

Our study indicates that the body iodine content is not an important determinant of thyroid ablation, when preparing the patients with either THW or rhTSH.

Limited value of repeat recombinant human thyrotropin (rhTSH)-stimulated thyroglobulin testing in differentiated thyroid carcinoma patients with previous negative rhTSH-stimulated thyroglobulin and undetectable basal serum thyroglobulin levels

CONTEXT

One year after initial treatment, low-risk differentiated thyroid cancer (DTC) patients undergo recombinant human (rh)TSH-stimulated serum thyroglobulin (Tg) (rhTSH-Tg) and neck ultrasound (US).

OBJECTIVE

The need for more rhTSH-Tg in these patients is controversial. We evaluated the utility of a second rhTSH-Tg in DTC patients 2-3 yr after their first evaluation.

RESULTS

At the first rhTSH-Tg, basal and stimulated serum Tg was undetectable in 68 of 85 patients. Neck US was unremarkable in all but one, who had evidence of lymph node disease. Seventeen of 85 patients had undetectable serum Tg that became positive after rhTSH, with negative imaging in 10 and evidence of disease in seven. Patients with no evidence of disease were reevaluated 2-3 yr later (second rhTSH-Tg). In patients in which the first stimulated Tg was undetectable, all had undetectable basal serum Tg, which remained undetectable after rhTSH in 66 of 67 patients (98.5%) and became detectable in one (1.5%) (positive neck US). In the 10 patients with detectable stimulated Tg in the first test, basal serum Tg and US were negative at the second test, but rhTSH-Tg became detectable in six. Compared with the first rhTSH-Tg, the second stimulated Tg in these six patients decreased in one, increased in three, and stabilized in two patients.

CONCLUSIONS

The second rhTSH-Tg was informative in patients who had first stimulated Tg detectable but not in those who had undetectable Tg at the first test, in which the only patient with recurrence was diagnosed by neck US. Thus, rhTSH-Tg should be repeated only in patients who have had a positive first rhTSH-Tg and negative imaging.

A comparison of 1850 (50 mCi) and 3700 MBq (100 mCi) 131-iodine administered doses for recombinant thyrotropin-stimulated postoperative thyroid remnant ablation in differentiated thyroid cancer

OBJECTIVE

Recently, a multicenter study in differentiated thyroid cancer (DTC) patients showed that 3700 MBq 131-iodine ((131)I) after recombinant human TSH (rhTSH) had a successful thyroid ablation rate similar to that obtained after thyroid hormone withdrawal. We investigated whether 1850 MBq (131)I had a similar successful rate to 3700 MBq in patients prepared with rhTSH.

DESIGN

A total of 72 patients with DTC were randomly assigned to receive 1850 (group A, n = 36) or 3700 MBq (group B, n = 36) (131)I after rhTSH. One injection of 0.9 mg rhTSH was administered for 2 consecutive days; (131)I therapy was delivered 24 h after the last injection, followed by a posttherapy whole-body scan. Successful ablation was assessed 6-8 months later.

RESULTS

Successful ablation (no visible uptake in the diagnostic whole-body scan after rhTSH stimulation) was achieved in 88.9% of group A and B patients. Basal and rhTSH-stimulated serum thyroglobulin was undetectable (<1 ng/ml) in 78.9% of group A and 66.6% of group B patients (P = 0.46). Similar rates of ablation were obtained in both groups also in patients with node metastases.

CONCLUSION

Therapeutic (131)I activities of 1850 MBq are equally effective as 3700 MBq for thyroid ablation in DTC patients prepared with rhTSH, even in the presence of node metastases.