Long-term effects of radioiodine treatment on thyroid functions and ultrasonographic features in patients with toxic adenoma and toxic multinodular goitre

OBJECTIVE

This study aimed to investigate the long-term effect of radioiodine (RAI) treatment on thyroid functions and ultrasonographic changes in the thyroid gland and toxic nodules.

METHODS

Thyroid function tests and ultrasonography reports of patients diagnosed with toxic adenoma (TA) or toxic multinodular goitre (TMNG) between 2000 and 2021 were retrospectively analysed.

RESULTS

We included 100 patients whom thyroid function and ultrasonography results were obtained from our outpatient clinic before and at least 36 months post-RAI. At the end of the follow-up period, the mean thyroid volume reduction in patients with TA and TMNG was 56.6% ± 3.1% and 51.1% ± 6.7%, respectively; the mean volume decrease of all toxic nodules was 80.5% ± 1.9%. The volume of the thyroid and toxic nodules was significantly reduced up to 12 years (p < 0.01). Between 3 and 10 years after RAI therapy, the annual incidence of hypothyroidism was 2.0% and 1.5% in the TA and TMNG groups, respectively. Toxic nodules were more frequently solid and hypoechoic in post-RAI ultrasounds (p < 0.01).

CONCLUSIONS

The volume of thyroid gland and toxic nodules continuously decreases, as the risk of hypothyroidism increases up to 10 years after RAI treatment. After RAI treatment, patients should be followed up to check their thyroid functions. In post-RAI examinations, toxic nodules may show ultrasonographic features suspicious for malignancy. History taking should include previous RAI therapies and old scintigraphy scans should be evaluated to avoid unnecessary procedures and non-diagnostic biopsy results.

Clinical usefulness of thyroid ultrasonography in patients with primary hypothyroidism

BACKGROUND AND OBJECTIVE

Despite the value of ultrasonography in the detection of chronic thyroiditis (CT) as well as in nodular goitre, it is often only indicated in patients with hypothyroidism if a palpable goitre or a thyroid mass is identified. The objective of the study is to evaluate the clinical usefulness of thyroid ultrasonography in patients with primary hypothyroidism without clinical suspicion of nodular goitre. And more specifically, to analyse its value in the aetiological diagnosis of hypothyroidism, and to evaluate its contribution in the detection and characterisation of coexisting subclinical thyroid nodular disease.

PATIENTS AND METHOD

Prospective cross-sectional observational study of 114 patients with primary hypothyroidism of CT or idiopathic aetiology, without symptoms or cervical palpation suspected of nodular goitre, who underwent a thyroid function test, a serological study of antithyroid antibodies, a thyroid ultrasonound and, when appropriate, a cytological study of the nodules found.

RESULTS

Ultrasonound allowed CT to be recognised as the cause of hypothyroidism in 19% of patients who had a negative serological study, and detected nodules larger than 9mm in 22 patients (16 with antithyroid antibodies). A cytological study was performed in 18 of the cases. Five patients underwent surgery, with carcinoma found in two of them.

CONCLUSIONS

Thyroid ultrasound is useful in the aetiological diagnosis of primary hypothyroidism as well as in the detection of a coexisting, unsuspected, but clinically relevant nodular goitre, so this examination should be indicated in the initial study of patients with primary hypothyroidism.

Improving Malignancy Prediction in AUS/FLUS Pediatric Thyroid Nodules with the Aid of Ultrasound

INTRODUCTION

The standard workup of thyroid nodules concerning for malignancy includes fine-needle aspiration (FNA). In 2015, the American Thyroid Association (ATA) guidelines for the management of pediatric thyroid nodules recommended that all nodules with a Bethesda III cytology undergo surgical resection.

OBJECTIVES

To correlate a Bethesda III cytology with histologic and clinical outcomes to determine the relevance of the ATA recommendations, and to evaluate whether Thyroid Imaging Reporting and Data System (TI-RADS) scoring could identify Bethesda III nodules at a lower risk of malignancy.

METHODS

A retrospective chart review of patients who had undergone thyroid nodule FNA from 2008 to 2018 was performed. Malignancy rates were determined for each Bethesda category. The reference standard was histopathology or 2-year follow-up of imaging outcomes for nonoperative cases. Ultrasound exams of Bethesda III nodules were reviewed and TI-RADS scores assigned.

RESULTS

A total of 143 FNA samples from 128 patients were identified. The mean age was 14.9 years (range 7-22). Twenty-two (15%) of the FNA samples were Bethesda III; the malignancy rate was 38%. A TI-RADS score was assigned in 20 of the 22 Bethesda III nodules. ROC analysis found an optimal cut-off for malignancy prediction of ≥7 points (risk category TR5). The negative predictive value was 85.7% (95% CI 35.9-99.6) and the positive predictive value was 83.3% (95% CI 57.2-98.2).

CONCLUSION

Although, at baseline, thyroid nodules with a Bethesda III classification carry a moderate risk of malignancy in the pediatric population, TI-RADS scoring can identify nodules with a lower risk within this group. If validated by larger studies, this can inform decision making and reduce unneeded surgery.

Cytological examination of the thyroid in children and adolescents after the Fukushima Nuclear Power Plant accident: the Fukushima Health Management Survey

The Fukushima Daiichi Nuclear Power Plant accident occurred on March 11 2011, following the Great East Japan Earthquake and tsunami. Radioactive materials, including I-131, were released into the environment after the accident. Shortly after, the prefectural government initiated the Fukushima Health Management Survey for monitoring the long-term health conditions of the residents of Fukushima Prefecture. In the survey, thyroid ultrasonography was scheduled for all people aged 18 years or younger who were living in Fukushima Prefecture at the time of disaster. The total number of examinees was approximately 370,000 in the Preliminary Baseline Survey (PBLS), and 380,000 in the first Full-scale Survey (FSS). First, thyroid ultrasonography was performed as the Primary Examination. When a thyroid nodule that meets the fine needle aspiration cytology (FNAC) guideline is detected, thyroid FNAC is performed. By the end of June 2017, the cytological specimens of 187 examinees had been interpreted as Malignant or Suspicious for Malignancy (SFM). In this article, the cytological results of whole categories are presented using the criteria of The Bethesda System for Reporting Thyroid Cytopathology. The total numbers of examinees with SFM or Malignant in PBLS and at the first FSS were 106 (62.0%) and 71 (38.0%), respectively. The data of the cytological results of SFM and Malignant were already reported. However, this is the first report of cytological data from categories other than SFM and Malignant. The results of the current study will contribute to future research into the thyroid conditions of children and adolescents.

Occult metastatic thyroid cancer diagnosed during breast cancer axillary sentinel node biopsy

SUMMARY

In most developed countries, breast carcinoma is the most common malignancy in women and while thyroid cancer is less common, its incidence is almost three to five times greater in women than in men. Since 1966, studies have demonstrated an association between thyroid and breast cancer and despite these studies, the mechanism/s by which they are related, remains unclear. We present a case of a 56-year-old lady who initially presented in 2014 with a screen detected left breast carcinoma but was subsequently found to have occult metastatic thyroid cancer to the axilla, diagnosed from a sentinel node biopsy from the primary breast procedure. The patient underwent a left mastectomy, left axillary dissection and total thyroidectomy followed by three courses of radioactive iodine ablation. Despite this, her thyroglobulin level continued to increase, which was secondary to a metastatic thyroid cancer parasternal metastasis. Breast and thyroid cancer presents metachronously or synchronously more often than by chance. With improving mortality in primary cancers, such as breast and differentiated thyroid cancer, it is likely that as clinicians, we will continue to encounter this association in practice.

LEARNING POINTS

There has been a long-standing observation of an association between breast and thyroid cancer although the exact mechanism of this association remains unclear. Our patient presented with thyroid cancer with an incidental diagnosis from a sentinel node biopsy during her primary breast operation for breast cancer and was also found to have a parasternal distant bony metastasis. Thyroid axillary metastases are generally rare. The interesting nature in which this patient's metastatic thyroid carcinoma behaved more like a breast carcinoma highlights a correlation between these two cancers. With improving mortality in these primary cancers, clinicians are likely to encounter this association in clinical practice. Systemic therapy for metastatic breast and thyroid cancers differ and therefore a clear diagnosis of metastasis is crucial.

Central hypothyroidism or subclinical hyperthyroidism: can they be confused with each other?

SUMMARY

Isolated, adult-onset central hypothyroidism is very rare, and its diagnosis can be challenging. A 42-year-old patient was referred for evaluation of a 2.8 cm thyroid nodule. She referred symptoms that could be attributed to hypothyroidism and thyroid tests showed low TSH and normal-low levels of free T4. However, evaluation of the remaining pituitary hormones and pituitary MRI were normal, yet a radionuclide scanning revealed that the thyroid nodule was 'hot' and the tracer uptake in the remaining thyroid tissue was suppressed. Interpretation of these studies led to a misdiagnosis of subclinical hyperthyroidism and the patient was treated with radioiodine. Soon after treatment, she developed a frank hypothyroidism without appropriate elevation of TSH and the diagnosis of central hypothyroidism was made a posteriori. Long term follow-up revealed a progressive pituitary failure, with subsequent deficiency of ACTH and GH. This case should alert to the possibility of overlooking central hypothyroidism in patients simultaneously bearing primary thyroid diseases able to cause subclinical hyperthyroidism.

LEARNING POINTS

Although rarely, acquired central hypothyroidism can occur in the absence of other pituitary hormone deficiencies. In these cases, diagnosis is challenging, as symptoms are unspecific and usually mild, and laboratory findings are variable, including low, normal or even slightly elevated TSH levels, along with low or low-normal concentrations of free T4. In cases with low TSH levels, the coexistence of otherwise common disorders able to cause primary thyroid hyperfunction, such as autonomous nodular disease, may lead to a misdiagnosis of subclinical hyperthyroidism.

Painless thyroiditis in a dupilumab-treated patient

SUMMARY

Dupilumab an inhibitor of the interleukin (IL)-4R-alpha subunit is used for the treatment of allergic diseases. The patient was a 49-year-old man who received dupilumab for the treatment of severe atopic dermatitis. He presented hyperthyroidism with elevated thyroglobulin and anti-thyroid antibody negativity at 4 months after the initiation of therapy. On scintigraphy, the thyroid radioiodine uptake was low. Ultrasonography showed a diffuse hypoechoic area in the thyroid gland. A pathological study revealed lymphocytic infiltration. The administration of dupilumab was continued because of his atopic dermatitis that showed an excellent response. The patient`s hyperthyroidism changed to hypothyroidism 3 weeks later. Six months later his thyroid function normalized without any treatment. We herein describe the case of a patient with atopic dermatitis who developed painless thyroiditis under treatment with dupilumab. To the best of our knowledge, this is the first report of this event in the literature.

LEARNING POINTS

Dupilumab, a fully human monoclonal antibody that blocks interleukin-4 and interleukin-13, has been shown to be effective in the treatment atopic dermatitis and asthma with eosinophilia. Painless thyroiditis is characterized by transient hyperthyroidism and hypothyroidism and recovery without anti-thyroid treatment. This is the first report of painless thyroiditis as an adverse effect of dupilumab, although conjunctivitis and nasopharyngitis are the main adverse effects of dupilumab.

Insulin autoimmune syndrome

SUMMARY

Insulin autoimmune syndrome (Hirata's disease) is a disorder caused by development of autoantibodies to insulin and manifested by hypoglycaemic syndrome. The overwhelming majority of physicians do not include it in the differential diagnosis of hypoglycaemic states because of a misconception of an extremely low prevalence of this condition. This results in unnecessary drug therapy and unjustified surgical interventions in patients that otherwise would be successfully treated conservatively. This disease is strongly associated with certain alleles of the HLA gene. In most cases, this condition develops in predisposed individuals taking drugs containing sulfhydryl groups. Formation of autoantibodies to insulin may be observed in patients with other autoimmune disorders, as well as in those with multiple myeloma or monoclonal gammopathy of undetermined significance. This paper presents the first Russian case report of insulin autoimmune syndrome in an adult patient.

LEARNING POINTS

Insulin autoimmune syndrome, Hirata's disease, anti-insulin antibodies, and hypoglycaemia.

Intermixed medullary and papillary thyroid cancer in a patient with renal cell carcinoma

SUMMARY

We report a rare case of concurrent medullary thyroid cancer (MTC) and papillary thyroid cancer (PTC) with intermixed disease in several of the lymph node (LN) metastases in a patient who was subsequently diagnosed with clear cell renal cell carcinoma (RCC). A 56 year old female presented with dysphagia and was found to have a left thyroid nodule and left superior cervical LN with suspicious sonographic features. Fine needle aspiration biopsy (FNAB) demonstrated PTC in the left thyroid nodule and MTC in the left cervical LN. Histopathology demonstrated multifocal PTC with 3/21 LNs positive for metastatic PTC. One LN in the left lateral neck dissection exhibited features of both MTC and PTC within the same node. In the right lobe, a 0.3 cm focus of MTC with extra-thyroidal extension was noted. Given persistent calcitonin elevation, a follow-up ultrasound displayed an abnormal left level 4 LN. FNAB showed features of both PTC and MTC on the cytopathology itself. The patient underwent repeat central and left radical neck dissection with 3/6 LNs positive for PTC in the central neck and 2/6 LNs positive for intermixed PTC and MTC in the left neck. There was no evidence of distant metastases on computed tomography and whole body scintigraphy, however a 1.9 x 2.5 cm enhancing mass within the right inter-polar kidney was discovered. This lesion was highly suspicious for RCC. Surgical pathology revealed a 2.5 cm clear cell RCC, Fuhrman grade 2/4, with negative surgical margins. She continues to be observed with stable imaging of her triple malignancies.

LEARNING POINTS

Mixed medullary-papillary thyroid neoplasm is characterized by the presence of morphological and immunohistochemical features of both medullary and papillary thyroid cancers within the same lesion. Simultaneous occurrence of these carcinomas has been previously reported, but a mixed disease within the same lymph node is an infrequent phenomenon. Prognosis of mixed medullary-papillary thyroid carcinomas is determined by the medullary component. Therefore, when PTC and MTC occur concurrently, the priority should be given to the management of MTC, which involves total thyroidectomy and central lymph node dissection. Patients with thyroid cancer, predominantly PTC, have shown higher than expected rates of RCC. To our knowledge, this is the first report describing the combination of MTC, PTC, and RCC in a single patient.

Lingual thyroid gland: it's time for awareness

SUMMARY

Lingual thyroid (LT) gland is the most common type of ectopic thyroid tissue, but it is an extremely rare presentation. We present a case of a 41-year-old Hispanic female patient complaining of dysphonia and dysphagia. As part of the evaluation, fiber optic flexible indirect laryngoscopy (FIL) was performed which revealed a mass at the base of the tongue. The morphological examination was highly suspicious for ectopic thyroid tissue and the diagnosis was confirmed with neck ultrasound and thyroid scintigraphy. Although the patient presented subclinical hypothyroidism, levothyroxine therapy was initiated with a favorable response which included resolution of symptoms and mass size reduction. Our case portrays how thyroid hormone replacement therapy (THRT) may lead to a reduction in the size of the ectopic tissue and improvement of symptoms, thus avoiding the need for surgical intervention which could result in profound hypothyroidism severely affecting the patients' quality of life.

LEARNING POINTS

Benign LT and malignant LT are indistinguishable clinically and radiographically for which histopathology is recommended. THRT, radioactive iodine 131 (RAI) therapy, and surgical excision are potential management options for LT. THRT may lead to size reduction of the ectopic tissue and resolution of symptoms avoiding surgical intervention.

Thyroid carcinoma with atypical metastasis to the pituitary gland and unexpected postmortal diagnosis

SUMMARY

Papillary thyroid gland carcinoma is the most common type of malignancy of the endocrine system. Metastases to the pituitary gland have been described as a complication of papillary thyroid cancer in few reported cases since 1965. We report the case of a 68-year-old female patient with a well-differentiated form of thyroid gland cancer. Despite it being the most common malignant cancer of the endocrine system, with its papillary form being one of the two most frequently diagnosed thyroid cancers, the case we present is extremely rare. Sudden cardiac arrest during ventricular fibrillation occurred during hospitalization. Autopsy of the patient revealed papillary carcinoma of the thyroid, follicular variant, with metastasis to the sella turcica, and concomitant sarcoidosis of heart, lung, and mediastinal and hilar lymph nodes. Not only does atypical metastasis make our patient's case most remarkable, but also the postmortem diagnosis of sarcoidosis makes her case particularly unusual.

LEARNING POINTS

The goal of presenting this case is to raise awareness of the clinical heterogeneity of papillary cancer and promote early diagnosis of unexpected metastasis and coexisting diseases to improve clinical outcomes. Clinicians must be skeptical. They should not fall into the trap of diagnostic momentum or accept diagnostic labels at face value. Regardless of the potential mechanisms, clinicians should be aware of the possibility of the coexistence of thyroid cancer and sarcoidosis as a differential diagnosis of lymphadenopathy. This case highlights the importance of the diagnostic and therapeutic planning process and raises awareness of the fact that one uncommon disease could be masked by another extremely rare disorder.

Complex management decisions in a woman with concurrent primary hyperparathyroidism and metastatic papillary thyroid carcinoma, both presenting during pregnancy

SUMMARY

A 40-year-old woman was hospitalised at 25-week gestation following a diagnosis of severe symptomatic hypercalcaemia (adjusted serum calcium 3.02 mmol/L). A diagnosis of primary hyperparathyroidism (PHP) was made on the basis of elevated parathyroid hormone (PTH) 11.2 pmol/L (reference range 1.5-6.9) and exclusion of familial hypocalciuric hypercalcaemia. Ultrasound examination of the neck did not convincingly demonstrate an abnormal or enlarged parathyroid gland and parathyroid scintigraphy was not performed due to maternal choice relating to perceived radiation risk to the foetus. At neck exploration during the 28th week of pregnancy a right lower pole parathyroid lesion was excised together with two abnormal lymph nodes (largest 1.6 cm). Histology confirmed a parathyroid adenoma and also papillary thyroid carcinoma deposits in the two resected lymph nodes. Post-operatively, levels of adjusted serum calcium normalised and pregnancy progressed uneventfully to term. Total thyroidectomy was performed 2 weeks after delivery revealing two small foci of papillary micro-carcinoma (largest 2.3 mm, one in each thyroid lobe) with no evidence of further metastatic tumour in lymph nodes removed during functional neck dissection. Radioiodine remnant ablation (RRA) was performed 2 months post thyroidectomy to allow for breast involution. The patient remains in full clinical and biochemical remission 9 years later. We present and review the difficult management decisions faced in relation to the investigation and treatment of PHP in pregnancy, further complicated by incidentally discovered locally metastatic pT1aN1aM0 papillary thyroid carcinoma.

LEARNING POINTS

PHP may have serious consequences during pregnancy and usually requires surgical management during pregnancy to reduce the risk of maternal and foetal complications. The indications for and optimal timing of surgical management are discussed. Localisation by parathyroid scintigraphy is controversial during pregnancy: modified dose regimes may be considered in preference as an alternative to unguided neck exploration. Breastfeeding is contraindicated for 6-8 weeks before radioactive-iodine remnant ablation (RRA) to prevent increased breast uptake. Breastfeeding is further contra-indicated until after a subsequent pregnancy. Incidentally discovered differentiated thyroid carcinoma (DTC) in cervical lymph nodes in some cases may be managed expectantly because in one quarter of thyroidectomies the primary tumour remains occult.

Concomitant medullary thyroid carcinoma with paraganglioma-like pattern and papillary thyroid carcinoma

SUMMARY

A 74-year-old man was referred to the Endocrinology Unit because of multinodular goiter. The dominant nodule (1.7 × 1.9 × 2.4 cm), at the medium-superior third of the left lobe, was inhomogeneously hypoechoic, with irregular margins, macrocalcifications and intranodular vascularization. Fine-needle aspiration biopsy (FNAB) was performed. The cytological diagnosis was TIR 2, benign, according to the 2013 Italian thyroid cytology classification system. Moderately high serum calcitonin (s-Ct) (61.5 pg/mL, n.r. 0-7.5) and normal CEA were detected. The Ct level in FNAB wash-out fluid (Ct-FNAB) was 1450 pg/mL. Based on s-Ct and Ct-FNAB levels, patient underwent total thyroidectomy. Macroscopically, a dominant circumscribed nodule of 2 ecm was described; the histological and immunohistochemical features identified medullary thyroid carcinoma (MTC) with paraganglioma (PG)-like pattern positive for Ct, CEA and chromogranin and negative for S-100 sustentacular cells (SC). Moreover, papillary carcinoma of 3 mm in the right lobe was also associated. No areas of hyperaccumulation of the tracer were documented at Ga68 PET/CT. No RET-proto-oncogene mutations were found. Post-surgery s-Ct levels were within normal range (4 pg/mL). Two years after thyroidectomy, the patient is still disease-free. We reported a case of sporadic and rare variant of MTC: this is the ninth described case of PG-like MTC. In this case, cytologically benign, the clinical suspicion arose from high Ct values at FNAB wash-out fluid. Even if clinical behavior of this variant seems indolent, additional studies are necessary to understand prognoses and predictive factors.

LEARNING POINTS

Several unusual histological variants of medullary thyroid carcinoma (MTC) have been described such as spindle cell, giant cell, clear cell, melanotic, squamous, angiosarcoma-like variants; even rarer is the paraganglioma (PG)-like pattern. We here describe a case of medullary PG-like thyroid carcinoma in a 74-year-old man. This is a rare histological variant of MTC hardly diagnosed by cytology, since immunohistochemical investigations are necessary. Measurement of calcitonin both in serum and in wash-out fluid from fine-needle aspiration could be an additional tool for an early and non-invasive identification of these variants.

Anaplastic thyroid carcinoma diagnosed after treatment of lenvatinib for papillary thyroid carcinoma

SUMMARY

Anaplastic transformation of a primary thyroid tumor whose process can be followed is rare. The objective this study is to report a case of anaplastic transformation of locally advanced papillary thyroid carcinoma after treatment with lenvatinib. A 74-year-old woman consulted a local physician because of cough and bloody sputum. Thyroid cancer with tracheal invasion was suspected on computed tomography (CT) imaging, and she visited our hospital for treatment. We suspected anaplastic thyroid cancer (ATC) and core needle biopsy was performed. Histologic sections of the core needle biopsy showed that the tumor formed a papillary structure, and we diagnosed papillary thyroid carcinoma. Surgery would have been difficult, and we initiated lenvatinib at a low dose of 8 mg/day. CT on day 40 of lenvatinib treatment revealed that the thyroid tumor had shrunk remarkably. CT on day 111 revealed that tumor regrowth and tracheal invasion had been exacerbated. Core needle biopsy was performed, and histologic sections of the core needle biopsy that was performed after regrowth of the tumor showed that individual cancer cells had large, irregular nuclei, and necrosis was also observed. The immunohistochemical findings were negative for thyroglobulin, and only a few cells were positive for thyroid transcription factor 1, and we diagnosed ATC. Anaplastic transformation of the target lesion may be one of the causes of lenvatinib treatment failure in differentiated thyroid carcinoma.

LEARNING POINTS

Anaplastic transformation of a primary thyroid tumor whose process can be followed is rare. The resistance mechanism of lenvatinib in treatment for differentiated thyroid carcinoma has not been clarified. Anaplastic transformation of the target lesion may be one of the causes of lenvatinib treatment failure in differentiated thyroid carcinoma.

Clinical challenges of a co-secreting TSH/GH pituitary adenoma

SUMMARY

Co-secreting thyrotropin/growth hormone (GH) pituitary adenomas are rare; their clinical presentation and long-term management are challenging. There is also a paucity of long-term data. Due to the cell of origin, these can behave as aggressive tumours. We report a case of a pituitary plurihormonal pit-1-derived macroadenoma, with overt clinical hyperthyroidism and minimal GH excess symptoms. The diagnosis was confirmed by pathology showing elevated thyroid and GH axes with failure of physiological GH suppression, elevated pituitary glycoprotein hormone alpha subunit (αGSU) and macroadenoma on imaging. Pre-operatively the patient was rendered euthyroid with carbimazole and underwent successful transphenoidal adenomectomy (TSA) with surgical cure. Histopathology displayed an elevated Ki-67 of 5.2%, necessitating long-term follow-up.

LEARNING POINTS

Thyrotropinomas are rare and likely under-diagnosed due to under-recognition of secondary hyperthyroidism. Thyrotropinomas and other plurihormonal pit-1-derived adenomas are more aggressive adenomas according to WHO guidelines. Co-secretion occurs in 30% of thyrotropinomas, requiring diligent investigation and long-term follow-up of complications.

The Malignancy Risk Assessment of Cytologically Indeterminate Thyroid Nodules Improves Markedly by Using a Predictive Model

OBJECTIVES

The majority of thyroid nodules are discovered incidentally, and the management may be a challenge if the fine needle aspiration specimen yields indeterminate findings. Our aim was to develop an individualized risk prediction model to provide an accurate estimate of cancer risk in patients with cytologically indeterminate thyroid nodules.

MATERIALS AND METHODS

Clinical records, ultrasound images, and cytopathology reports of patients who underwent thyroidectomy were retrospectively reviewed. Logistic regression analysis was used to identify the predictive ability of each variable for malignancy, and a nomogram was built by integrating patients' age, multiplicity of nodules, cytology results, and suspicious ultrasound features, such as microcalcifications and irregular margins.

RESULTS

For the 233 indeterminate nodules according to the Bethesda System for Reporting Thyroid Cytopathology, the malignancy rates of the subgroups "atypia of undetermined significance," "suspicious follicular neoplasia," and "suspicious for malignancy" were 44.3, 47.7, and 88.0%, respectively. It was found that the Bethesda category "suspicious for malignancy," microcalcifications, and irregular margins were independent risk factors for malignancy. The area under the receiver operating characteristics curve was 0.784, which suggested that the presented nomogram had considerable discriminative performance.

CONCLUSIONS

The nomogram developed in our study accurately predicts the malignancy risk of thyroid nodules with indeterminate cytology by using clinical, cytological, and ultrasonographic features.

Switch from tablet levothyroxine to oral solution resolved reduced absorption by intestinal parasitosis

Reduced intestinal absorption of levothyroxine (LT4) is the most common cause of failure to achieve an adequate therapeutic target in hypothyroid patients under replacement therapy. We present the case of a 63-year-old woman with autoimmune hypothyroidism previously well-replaced with tablet LT4 who became unexpectedly no more euthyroid. At presentation, the patient reported the onset of acute gastrointestinal symptoms characterized by nausea, loss of appetite, flatulence, abdominal cramps and diarrhea, associated with increase of thyrotropin levels (TSH: 11 mIU/mL). Suspecting a malabsorption disease, a thyroxine solid-to-liquid formulation switch, at the same daily dose, was adopted to reach an optimal therapeutic target despite the gastrointestinal symptoms persistence. Oral LT4 solution normalized thyroid hormones. Further investigations diagnosed giardiasis, and antibiotic therapy was prescribed. This case report is compatible with a malabsorption syndrome caused by an intestinal parasite (Giardia lamblia). The reduced absorption of levothyroxine was resolved by LT4 oral solution. Learning points: The failure to adequately control hypothyroidism with oral levothyroxine is a common clinical problem. Before increasing levothyroxine dose in a patient with hypothyroidism previously well-controlled with LT4 tablets but no more in appropriate therapeutic target, we suggest to investigate non adhesion to LT4 therapy, drug or food interference with levothyroxine absorption, intestinal infection, inflammatory intestinal disease, celiac disease, lactose intolerance, short bowel syndrome after intestinal or bariatric surgery, hepatic cirrhosis and congestive heart failure. LT4 oral solution has a better absorptive profile than the tablet. In hypothyroid patients affected by malabsorption syndrome, switch of replacement therapy from tablet to liquid LT4 should be tested before increasing the dose of LT4.

A thyroid gland with over 30 foci of papillary thyroid carcinoma with activating BRAF V600E mutation

Multifocal papillary thyroid carcinoma (PTC) is common and the number of tumor foci rarely exceeds ten. The mechanism of multifocal disease is debated, with the two main hypotheses consisting of either intrathyroidal metastatic spread from a single tumor or independent multicentric tumorigenesis from distinct progenitor cells. We report the case of a 46-year-old woman who underwent total thyroidectomy and left central neck lymph node dissection after fine-needle aspiration of bilateral thyroid nodules that yielded cytological findings consistent with PTC. Final pathology of the surgical specimen showed an isthmic dominant 1.5 cm classical PTC and over 30 foci of microcarcinoma, which displayed decreasing density with increasing distance from the central lesion. Furthermore, all malignant tumors and lymph nodes harbored the activating BRAF V600E mutation. The present case highlights various pathological features that support a mechanism of intraglandular spread, namely a strategic isthmic location of the primary tumor, radial pattern of distribution and extensive number of small malignant foci and BRAF mutational homogeneity. Learning points: Multifocal papillary thyroid carcinoma (PTC) is commonly seen in clinical practice, but the number of malignant foci is usually limited to ten or less. There is no clear consensus in the literature as to whether multifocal PTC arises from a single or multiple distinct tumor progenitor cells. Strategic location of the dominant tumor in the thyroid isthmus may favor intraglandular dissemination of malignant cells by means of the extensive lymphatic network. An important pathological finding that may be suggestive of intrathyroidal metastatic spread is a central pattern of distribution with a reduction in the density of satellite lesions with increasing distance from the dominant focus. PTCs originating from the isthmus with intraglandular metastatic dissemination behave more aggressively. As such, a more aggressive treatment course may be warranted, particularly with regard to the extent of surgery.

Thyroid Ultrasound: More Sensitive than Radioactive Iodine Imaging in Detecting Recurrence of Papillary Thyroid Cancer in Two Pediatric Patients

BACKGROUND

Papillary thyroid cancer (PTC) is an uncommon pediatric disease with an excellent prognosis. In follow-up surveillance, neck ultrasound (US), basal and thyroid-stimulating hormone-stimulated serum thyroglobulin (Tg) levels, and diagnostic whole-body radioactive iodine scans (DxWBS) have been traditionally used in both adults and children for the detection of recurrence or metastases of PTC.

METHODS

Two pediatric patients with metastatic PTC were followed after standard ablative treatment with routine neck US and serum Tg levels, as well as periodic DxWBS.

RESULTS

Neck US identified recurrent and metastatic PTC which DxWBS failed to detect.

CONCLUSION

Neck US was superior to DxWBS in the detection of recurrent PTC in these 2 pediatric patients. These findings are consistent with the 2015 American Thyroid Association (ATA) Guidelines that neck US is an ideal imaging modality in pediatric patients for the surveillance of PTC local recurrence or lymph node metastases.

Thyroid ultrasonography reporting: consensus of Italian Thyroid Association (AIT), Italian Society of Endocrinology (SIE), Italian Society of Ultrasonography in Medicine and Biology (SIUMB) and Ultrasound Chapter of Italian Society of Medical Radiology (SIRM)

Thyroid ultrasonography (US) is the gold standard for thyroid imaging and its widespread use is due to an optimal spatial resolution for superficial anatomic structures, a low cost and the lack of health risks. Thyroid US is a pivotal tool for the diagnosis and follow-up of autoimmune thyroid diseases, for assessing nodule size and echostructure and defining the risk of malignancy in thyroid nodules. The main limitation of US is the poor reproducibility, due to the variable experience of the operators and the different performance and settings of the equipments. Aim of this consensus statement is to standardize the report of thyroid US through the definition of common minimum requirements and a correct terminology. US patterns of autoimmune thyroid diseases are defined. US signs of malignancy in thyroid nodules are classified and scored in each nodule. We also propose a simplified nodule risk stratification, based on the predictive value of each US sign, classified and scored according to the strength of association with malignancy, but also to the estimated reproducibility among different operators.

Gender-specific correlation of intranodular chronic lymphocytic thyroiditis with thyroid nodule size, echogenicity, and histologically-verified cytological class of malignancy risk

No data are available on the cytologically and histologically demonstrated presence of intranodular chronic lymphocytic thyroiditis (ICLT) and on the ICLT relationship with thyroid nodule characteristics such as size, echotexture and nature (benign or malignant). We wished to fill this gap by analyzing data in a gender-specific fashion. We studied 408 thyroid nodules from 408 consecutive persons (325 females and 83 males). Nodules were isoechoic (n = 268) or hypoechoic (n = 140), ICLT +ve (n = 113 [27.7%]) or ICLT -ve (n = 295), cytologically low-risk (n = 197) or high-risk (n = 211), histologically benign (n = 263) or malignant (n = 145). ICLT prevailed in females (97/113) and in hypoechoic nodules (58/140 [41.4%] vs 55/268 [20.5%], P < 0.0001). Compared to males, females had (i) smaller nodules (18.5 ± 9.4 vs 23.3 ± 13.4 mm, P = 0.0002), a difference due to the isoechoic nodules (21.1 ± 9.8 vs 26.6 ± 14.1 mm, P = 0.0006), (ii) lower rates of high-risk nodules (161/325 [49.5%] vs 50/83 [60.2%], P = 0.082) and malignant nodules (110/325 [33.8%] vs 35/83 [42.2%] P = 0.16). ICLT +ve nodules were smaller than the ICLT -ve ones (15.4 ± 6.9 vs 20.9 ± 11.2 mm, P < 0.0001), a difference due to the isoechoic nodules (17.5 ± 6.5 vs 23.6 ± 11.7 mm, P = 0.0003). The smallest nodules were hypoechoic, cancerous and ICLT +ve nodules in males (9.5 ± 4.0 mm); the largest were isoechoic, cytologically risky and ICLT -ve in males (29.1 ± 13.2 mm). Compared to ICLT -ve nodules, malignancy prevailed in ICLT +ve nodules (55/113 [48.7%] vs 90/295 [30.5%], P = 0.0006), both in hypoechoic (37/58 [63.8%] vs 41/82 [50.0%]) and isoechoic nodules (18/55 [32.7%] vs 49/213 [23.0%]). ICLT +ve hypoechoic nodules of females and ICLT -ve hypoechoic nodules of males had the greatest rate of malignancy (67% both), while ICLT -ve isoechoic nodules of females had the lowest (19%). In conclusion, presence/absence of ICLT is associated with some sexually dimorphic characteristics of thyroid nodules. Adding the specification of ICLT positivity/negativity in cytological reports may help improving the risk of malignancy at least in some groups of thyroid nodules.

Patients with papillary thyroid carcinoma associated with high stimulated serum calcitonin levels

Among various substances produced by C-cells, the most important one is calcitonin (CT) that is used for detection, post-operative follow-up and evaluation of individuals at risk of developing medullary thyroid carcinoma (MTC). However, the role of serum CT measurement in the evaluation of thyroid nodules has been widely discussed, and there is still no consensus about the role of CT in the initial evaluation of all thyroid nodules. Two patients with thyroid nodules whose fine-needle aspiration results were compatible with benign cytology besides having mildly elevated basal serum calcitonin levels were reported. Calcitonin responses (peak levels were 313 and 229 pg/mL, respectively) to calcium stimulation test were compatible with the possible diagnosis of MTC. However, the final diagnosis was papillary thyroid carcinoma of the thyroid gland. There are limited numbers of case reports showing such an increased serum calcitonin responses to calcium stimulation test associated with papillary or follicular thyroid carcinoma of the thyroid. We suggest to measure serum CT level once and in case of normal levels, no further CT measurement is necessary. Physicians should keep in mind that thyroid carcinomas other than MTCs may also be associated with high serum CT levels.

Learning points

Although serum calcitonin is a valuable tumor marker for MTC, it is well known that mild elevations may be seen in some other diseases such as Hashimoto thyroiditis, neuroendocrine tumors or due to medications such as proton pump inhibitors, calcium salts, beta blockers and glucocorticoids.Those two cases indicate that high calcitonin responses to calcium stimulation test, mimicking MTC, may also be seen in patients with papillary thyroid carcinoma although the mechanism is not clear.

Correlation of normal thyroid ultrasonography with thyroid tests

BACKGROUND

Thyroid disorders are frequently seen in the community. Thyroid ultrasonography (US) is commonly used in the diagnosis of thyroid diseases. The relationship between heterogeneous echogenicity of thyroid gland and thyroid tests are well known.

METHODS

The aim of this study is to evaluate the correlation of normal US with the thyroid tests. A total of 681 individuals were enrolled in the study. Individuals were separated into two groups as normal (group 1) and hypoechoic (group 2) according to the echogenicity in US. Subjects with nodular thyroid lesions were excluded from the study. Thyroid stimulating hormone (TSH), free T4 (fT4), thyroid peroxidase antibody (TPOAb) and anti-thyroglobulin antibody (TgAb) values were recorded in both groups and thyroid stimulating hormone receptor antibody (TRAb) was recorded in individuals with low TSH.

RESULTS

86.1% of individuals in group 1 had normal TSH, 93.7% had normal thyroid antibodies and in 77.6% of individuals, all thyroid tests performed were normal. In the 6.9% of the group 2, all reviewed thyroid tests were normal (P<0.001).

CONCLUSIONS

Our study shows that US is correlated with normal thyroid function tests and is a valuable tool in the prediction of normal thyroid function.

Is outcome of differentiated thyroid carcinoma influenced by tumor stage at diagnosis?

BACKGROUND

There is no international consensus on surveillance strategies for differentiated thyroid carcinoma (DTC) after radiotherapy for childhood cancer. Ultrasonography could allow for early detection of DTC, however, its value is yet unclear since the prognosis of DTC is excellent. We addressed the evidence for the question: 'is outcome of DTC influenced by tumor stage at diagnosis?'.

METHODS

A multidisciplinary working group answered the sub-questions: 'is recurrence or mortality influenced by DTC stage at diagnosis? Does detection of DTC at an early stage contribute to a decline in adverse events of treatment?' The literature was systematically reviewed, and conclusions were drawn based on the level of evidence (A: high, B: moderate to low, C: very low).

RESULTS

In children, level C evidence was found that detection of DTC at an early stage is associated with lower recurrence and mortality rates. No evidence was found that it influences morbidity rates. In adults, clear evidence was found that less advanced staged DTC is a favorable prognostic factor for recurrence (level B) and mortality (level A). Additionally, it was found that more extensive surgery increases the risk to develop transient hypoparathyroidism (level A) and that higher doses of radioiodine increases the risk to develop second primary malignancies (level B).

CONCLUSION

Identification of DTC at an early stage is beneficial for children (very low level evidence) and adults (moderate to high level evidence), even considering that the overall outcome is excellent. These results are an important cornerstone for the development of guidelines for childhood cancer survivors at risk for DTC.

Delayed surgery for parathyroid adenoma misdiagnosed as a thyroid nodule and treated with radiofrequency ablation

Primary hyperparathyroidism occurs as a result of isolated parathyroid adenoma in 80% to 85% of all cases. A (99m)technetium ((99m)Tc) sestamibi scan or neck ultrasonography is used to localize the neoplasm prior to surgical intervention. A 53-year-old female was referred for the exclusion of metabolic bone disease. She presented with low back pain that had persisted for the past 6 months and elevated serum alkaline phosphatase (1,253 IU/L). Four years previously, she had been diagnosed at a local hospital with a 2.3-cm thyroid nodule, which was determined to be pathologically benign. Radiofrequency ablation was performed at the same hospital because the nodule was still growing during the follow-up period 2 years before the visit to our hospital, and the procedure was unsuccessful in reducing the size of the nodule. The results of the laboratory tests in our hospital were as follows: serum calcium, 14.6 mg/dL; phosphorus, 3.5 mg/dL; and intact parathyroid hormone (iPTH), 1,911 pg/mL. Neck ultrasonography and (99m)Tc sestamibi scan detected a 5-cm parathyroid neoplasm in the left lower lobe of the patient's thyroid; left parathyroidectomy was performed. This case indicated that thyroid ultrasonographers and pathologists need to be experienced enough to differentiate a parathyroid neoplasm from a thyroid nodule; (99m)Tc sestamibi scan, serum calcium, and iPTH levels can help to establish the diagnosis of parathyroid neoplasm.

Ultrasonographic thyroid nodular findings in Japanese children

PURPOSE

The Fukushima Health Management Survey conducted after the accident at the Fukushima Nuclear Power Plant included thyroid ultrasound examinations for children aged ≤18 years at the time of the accident. The purpose of this study was to investigate the frequency of thyroid nodular lesions detected using high-quality ultrasonography in a general population of Japanese children, in whom such data have not been previously characterized.

METHODS

The current study investigated 4,365 free-living children aged between 3 and 18 years in three Japanese prefectures (Aomori, Yamanashi and Nagasaki). The same ultrasonography equipment as that used in the Fukushima Survey was employed to observe thyroid nodular lesions. The following categories of findings were used-'A', further examinations are not necessary; 'B', the presence of thyroid nodules with a diameter of ≥5.1 mm or thyroid cysts with a diameter of ≥20.1 mm; and 'C', immediate further examinations are required. As a sub-category of 'A', 'A1' was defined as the absence of nodules or cysts, and 'A2' was defined as the presence of thyroid nodules with a diameter of ≤5.0 mm or thyroid cysts with a diameter of ≤20.0 mm.

RESULTS

Overall, 4,321 (99 %) of the total participants were classified with a status of 'A' and 44 (1 %) were classified with a status of 'B'. No participants were classified with a status of 'C'. A total of 56.5 % of the total participants was classified with a status of 'A2'. Thyroid nodules were identified in 1.6 % of the total participants and thyroid cysts were identified in 56.9 % of the participants.

CONCLUSION

The current study provides data regarding the actual frequency of ultrasonographically detected thyroid nodular lesions among the Japanese children. These results would be useful for evaluating thyroid findings in Japanese children, although careful interpretation is required.