Thyroid Parenchyma Research Articles

5118 When Thyroid Gland Is Not Made Of Thyroid Cells

Abstract Disclosure: A. Bulut: None. L. Ma: None. J.P. Noordzij: None. S.Y. Lee: None. Introduction: Neurofibroma is a type of peripheral nerve tumor that can arise sporadically or be a part of neurofibromatosis type 1 (NF1), a rare genetic disorder. Neurofibromas within the thyroid gland are extremely rare. Here, we present the fifth reported case of primary neurofibroma of thyroid gland. Case: A 60-year-old woman with history of systemic lupus erythematosus and hypertension presented with enlargement of left thyroid gland. She was diagnosed with Graves’ disease 40 years ago, which was treated with right thyroid lobectomy one year after the initial diagnosis. Five years after the surgery, she had recurrence of her symptoms and received radioactive iodine ablation with subsequent hypothyroidism. On presentation to endocrine clinic, she had thyroid ultrasound (US), which showed surgically absent right thyroid lobe and enlarged heterogenous left thyroid lobe measuring 5.1 cm x 3.8 cm x 3.9 cm with scant blood flow without discrete nodules. In interim, patient developed dysphagia and globus sensation. Repeat thyroid US showed enlargement of left lobe to 5.6 cm x 3.7 cm x 4.7 cm. Patient underwent completion thyroidectomy. Surgical pathology showed neurofibroma (S-100+, CD34+ and MSA-) without any thyroid parenchyma. Whole-body scan revealed no other evidence of tumors. Patient was referred for genetic analysis. Discussion: Neurofibromas are benign peripheral nerve system tumors primarily consist of Schwann cells along with other components of perineurium. They can occur as a sporadic lesion which accounts for 90% of solitary neurofibroma cases or be a part of NF1 on rare occasions. NF1 is an autosomal dominant genetic disorder due to germline mutation in NF1 gene located on chromosome 17q11.2, whose manifestations include café-au-lait macules, Lisch nodules, skeletal abnormalities, neurological deficits, and other benign and malignant tumors. Neurofibromas are the hallmarks of NF1. There are only few cases in the literature reported neurofibromas adjacent to or originating from thyroid gland. To the best of our knowledge, there have been only four other cases reporting primary neurofibroma of thyroid gland, one of which developed from thyroid capsule. Our patient most likely has primary neurofibroma of thyroid gland given the lack of syndromic features, however, genetic testing is needed in order to rule out NF1. In conclusion, clinicians should consider neurofibroma in their differential in cases of enlarging thyroid gland or nodules, especially in the presence of other clinical features. Presentation: 6/1/2024

5118 When Thyroid Gland is Not Made of Thyroid Cells

Abstract Disclosure: A. Bulut: None. L. Ma: None. J.P. Noordzij: None. S.Y. Lee: None. Introduction: Neurofibroma is a type of peripheral nerve tumor that can arise sporadically or be a part of neurofibromatosis type 1 (NF1), a rare genetic disorder. Neurofibromas within the thyroid gland are extremely rare. Here, we present the fifth reported case of primary neurofibroma of thyroid gland. Case: A 60-year-old woman with history of systemic lupus erythematosus and hypertension presented with enlargement of left thyroid gland. She was diagnosed with Graves’ disease 40 years ago, which was treated with right thyroid lobectomy one year after the initial diagnosis. Five years after the surgery, she had recurrence of her symptoms and received radioactive iodine ablation with subsequent hypothyroidism. On presentation to endocrine clinic, she had thyroid ultrasound (US), which showed surgically absent right thyroid lobe and enlarged heterogenous left thyroid lobe measuring 5.1 cm x 3.8 cm x 3.9 cm with scant blood flow without discrete nodules. In interim, patient developed dysphagia and globus sensation. Repeat thyroid US showed enlargement of left lobe to 5.6 cm x 3.7 cm x 4.7 cm. Patient underwent completion thyroidectomy. Surgical pathology showed neurofibroma (S-100+, CD34+ and MSA-) without any thyroid parenchyma. Whole-body scan revealed no other evidence of tumors. Patient was referred for genetic analysis. Discussion: Neurofibromas are benign peripheral nerve system tumors primarily consist of Schwann cells along with other components of perineurium. They can occur as a sporadic lesion which accounts for 90% of solitary neurofibroma cases or be a part of NF1 on rare occasions. NF1 is an autosomal dominant genetic disorder due to germline mutation in NF1 gene located on chromosome 17q11.2, whose manifestations include café-au-lait macules, Lisch nodules, skeletal abnormalities, neurological deficits, and other benign and malignant tumors. Neurofibromas are the hallmarks of NF1. There are only few cases in the literature reported neurofibromas adjacent to or originating from thyroid gland. To the best of our knowledge, there have been only four other cases reporting primary neurofibroma of thyroid gland, one of which developed from thyroid capsule. Our patient most likely has primary neurofibroma of thyroid gland given the lack of syndromic features, however, genetic testing is needed in order to rule out NF1. In conclusion, clinicians should consider neurofibroma in their differential in cases of enlarging thyroid gland or nodules, especially in the presence of other clinical features. Presentation: 6/1/2024

8578 Papillary Thyroid Carcinoma in Autonomous Nodule with Low Risk Characteristics in Adolescent

Abstract Disclosure: A. Aponte Velez: None. M.M. Mangual Garcia: None. Thyroid nodules in children are uncommon but are known to carry a greater risk of malignancy than adult thyroid nodules. Additionally, differentiated thyroid cancer (DTC) in children is more commonly found with extrathyroidal extension and metastases which makes the approach and treatment similar but with important differences. The incidence of DTC in children is increasing, making a personalized evaluation of thyroid nodules in pediatric patients even more valuable. Guidelines recommend evaluation of nodules based on sonographic characteristics rather than size of nodule. However, not having worrisome sonographic characteristics may not be as reassuring as in adult patients. A 13 year old female patient presented with a palpable non tender right sided solid thyroid mass. She had no family history of thyroid cancer or history of irradiation. Thyroid function tests were remarkable for TSH:0.017 and positive thyroid stimulating immunoglobulin. Thyroid Ultrasound findings described heterogenous parenchyma with multiple discrete lesions on right thyroid lobe with a dominant solid isoechoic nodule at upper lobe measuring 2.1 x 3.5 x 1.9cm and a smaller nodule in lower lobe. Thyroid scan demonstrated a large functional hot nodule occupying most of right thyroid lobe with suppression of rest of thyroid parenchyma. Ultrasound guided FNA was performed of this lesion and results were negative for malignancy. Patient underwent total thyroidectomy with pathology report revealing right thyroid nodule encapsulated classical variant of papillary thyroid carcinoma. No lymph node metastases were identified. Non neoplastic thyroid parenchyma revealed chronic lymphocytic thyroiditis. Patient underwent radioiodine therapy with Whole Body Scan post radioiodine therapy demonstrating focal increased radionuclide localization at in region of neck consistent with functional thyroid tissue. There was no evidence of metastatic disease. In children, risk of malignancy is underestimated in ultrasonography and cytology. In this patient, papillary thyroid carcinoma was identified despite being stratified as having low risk of malignancy based on ultrasonography characteristics, hyperfunctioning nodule in scintigraphy study along with negative FNA results. Hyperfunctional nodules are usually reassuring for low risk of malignancy but rarely DTC can be found as in our patient. Guidelines agree that FNA is not recommended in functional nodules as surgical resection is the main therapy in children. However, surgery may be deferred if subclinical hyperthyroidism and low risk sonographic characteristics are present such as in our patient. If surgery had been deferred, based on low risk of malignancy, the risk of progression of disease would have been higher. Prognosis of DTC in children is good but the recurrence rate along with morbidity at such a young age may improve with more studies of DTC in children. Presentation: 6/2/2024

12556 Medullary Thyroid Cancer With Persistent Elevation Of Carcinoembryonic Antigen: Case Report

Abstract Disclosure: M.S. Campana: None. Introduction: Medullary thyroid Cancer (MTC) is a rare neuroendocrine tumor that originates from thyroid parafollicular C-cells and represents 5 % of all thyroid cancers. MTC can be sporadic (75%) or hereditary (25%) associated with multiple endocrine neoplasia type 2 syndrome (MEN2). Serum calcitonin (Ctn) and carcinoembryonic antigen (CEA) are its tumor markers. We report a case of persistently elevated CEA levels despite an undetectable Ctn in a patient with MTC after initial thyroid lobectomy. Description of the case: A 42-year-old woman self-identified a neck lump after intentional weight loss. A neck US showed a right lobe thyroid nodule which resulted as suspicious for malignancy (Bethesda V) with subsequent right lobectomy. Pathology reported a 2.6 cm unexpected MTC with negative surgical margins, extrathyroidal extension, angioinvasion, and lymphatic invasion. No cervical lymph nodes (LNs) were removed. Immunohistochemistry was positive for CEA, chromogranin A, synaptophysin, and Ctn. T2 Nx. One month after lobectomy, the Ctn was 10.5 (0-3.0 pg/mL) and CEA 205.2 (0-3.0 ng/mL Non-smoker; 0-5.0 ng/mL smoker). The patient was then referred to our clinic for further management. Laboratories showed normal serum calcium, PTH, and fractionated plasma metanephrine/normetanephrine. A 2-month post-operative Ctn was undetectable, but CEA was elevated at 24.5. Subsequently, we broaden imaging studies to include neck US, CT neck /chest with contrast, and MRI abdomen pelvis with contrast. The only remarkable finding was a 6.7 cm pelvic mass with normal Ca-125. Genetic testing was negative for germline RET, ruling out MEN2. Patient underwent completion left lobectomy with prophylactic bilateral central neck dissection. Pathology showed benign thyroid parenchyma with multinodular hyperplasia and 0/12 LNs. Because of concerning pelvic mass, the patient was referred to OB/GYN. She underwent a laparoscopic bilateral salpingo-oophorectomy. Pathology showed a follicular ovarian cyst, negative for malignancy. A year post-completion total thyroidectomy Ctn remains undetectable, and a CEA is normal at 1.3. Discussion: Because Ctn was already undetectable 1 month after lobectomy with persistent elevated CEA a complete total thyroidectomy with prophylactic bilateral central neck dissection was indicated to achieve operative cure. Ctn is specific to MTC but variable. CEA is more reproducible with less variability; however, it is not specific to MTC and can also be elevated in smokers, benign breast and genitourinary disease, emphysema, cirrhosis, and cancer of colon, rectum, liver, genitourinary, and lung. If residual disease is present, Ctn tends to be proportionally more elevated than CEA. When the opposite occurs, poorly differentiated MTC with possibility of distant metastases vs. a second primary malignancy vs. a distant benign neoplasm known to elevate CEA need to be ruled out. Presentation: 6/2/2024

8062 Uncommon Presentation of Multiple Myeloma as a Rapidly Growing Thyroid Goiter Initially Thought to be Hashimoto's Thyroiditis

Abstract Disclosure: M.S. Shah: None. S. Humayon: None. K.P. Sanu: None. C. Peñaherrera: None. We present a unique case of an 85-year-old female with rapidly growing anterior neck swelling and subclinical hyperthyroidism, initially suggestive of Hashimoto's thyroiditis. The goiter initially responded well to steroids but rebounded back in size despite two courses of prednisone. This prompted further diagnostic workup which revealed unexpected findings, ultimately leading to the diagnosis of multiple myeloma involving the thyroid parenchyma and lymph nodes. The patient had no history of thyroid disorders or recent upper respiratory tract infections. She exhibited sudden neck swelling, mild subclinical hyperthyroidism, and positive TPO antibodies. Initial fine needle aspiration suggested lymphoid tissue with Hurthle cell differentiation, raising suspicion of Hashimoto's thyroiditis. Flow cytometry supported this diagnosis, but the potential for a Hurthle cell neoplasm persisted. Prednisone temporarily reduced thyroid size, but disease recurrence necessitated surgical excisional and incisional biopsies. Subsequent biopsies revealed plasma cell neoplasms consistent with multiple myeloma. The pathologic report confirmed MYC rearrangement, indicative of multiple myeloma involvement in lymph nodes and thyroid tissue. Protein electrophoresis revealed two restricted bands migrating in the gamma globin region. The patient experienced subclinical hyperthyroidism that evolved into euthyroidism over a month. Incidental findings included non-invasive, low grade papillary urothelial carcinoma. Disease progression was evident in a follow-up PET/CT, prompting oncology consultation. The patient initiated Revlimid with chemotherapy. Levothyroxine was prescribed for postoperative hypothyroidism, with adjustments based on thyroid panel results. This case report illustrates the intricate diagnostic challenges posed by multiple myeloma masquerading as a thyroid disorder. The unexpected evolution of the disease, marked by MYC rearrangement and metastatic spread, emphasizes the need for heightened vigilance in managing such cases. Clinicians should consider alternative diagnoses when treatment efforts fail to provide adequate response. This will ensure timely and appropriate management in clinical practice. This report contributes valuable insights into the diagnostic complexities and multidisciplinary considerations for addressing similar presentations in endocrine and oncology settings. Presentation: 6/1/2024

8062 Uncommon Presentation Of Multiple Myeloma As A Rapidly Growing Thyroid Goiter Initially Thought To Be Hashimoto's Thyroiditis

Abstract Disclosure: M.S. Shah: None. S. Humayon: None. K.P. Sanu: None. C. Peñaherrera: None. We present a unique case of an 85-year-old female with rapidly growing anterior neck swelling and subclinical hyperthyroidism, initially suggestive of Hashimoto's thyroiditis. The goiter initially responded well to steroids but rebounded back in size despite two courses of prednisone. This prompted further diagnostic workup which revealed unexpected findings, ultimately leading to the diagnosis of multiple myeloma involving the thyroid parenchyma and lymph nodes. The patient had no history of thyroid disorders or recent upper respiratory tract infections. She exhibited sudden neck swelling, mild subclinical hyperthyroidism, and positive TPO antibodies. Initial fine needle aspiration suggested lymphoid tissue with Hurthle cell differentiation, raising suspicion of Hashimoto's thyroiditis. Flow cytometry supported this diagnosis, but the potential for a Hurthle cell neoplasm persisted. Prednisone temporarily reduced thyroid size, but disease recurrence necessitated surgical excisional and incisional biopsies. Subsequent biopsies revealed plasma cell neoplasms consistent with multiple myeloma. The pathologic report confirmed MYC rearrangement, indicative of multiple myeloma involvement in lymph nodes and thyroid tissue. Protein electrophoresis revealed two restricted bands migrating in the gamma globin region. The patient experienced subclinical hyperthyroidism that evolved into euthyroidism over a month. Incidental findings included non-invasive, low grade papillary urothelial carcinoma. Disease progression was evident in a follow-up PET/CT, prompting oncology consultation. The patient initiated Revlimid with chemotherapy. Levothyroxine was prescribed for postoperative hypothyroidism, with adjustments based on thyroid panel results. This case report illustrates the intricate diagnostic challenges posed by multiple myeloma masquerading as a thyroid disorder. The unexpected evolution of the disease, marked by MYC rearrangement and metastatic spread, emphasizes the need for heightened vigilance in managing such cases. Clinicians should consider alternative diagnoses when treatment efforts fail to provide adequate response. This will ensure timely and appropriate management in clinical practice. This report contributes valuable insights into the diagnostic complexities and multidisciplinary considerations for addressing similar presentations in endocrine and oncology settings. Presentation: 6/1/2024

Psammoma bodies in thyroid: are they always indicative of malignancy? A multi-institutional study.

Traditionally, psammoma bodies (PB) have been considered as tale-tell evidence of papillary thyroid carcinoma (PTC) and are frequently encountered in classic and other subtypes of PTCs. However, the presence of PBs in the thyroid gland does not always indicate malignancy. The leading hypothesis on their origin suggests that PB are remnants of papillary structures that have undergone thrombosis, necrosis, and subsequent calcification. From January 2010 to May 2024, 26 patients with psammoma bodies associated with benign thyroid lesions, mainly thyroid follicular nodular disease (TFND), Hashimoto thyroiditis (HT), Graves' disease, and follicular adenomas, were found. The case cohort included 16 females and 10 males with a median age of 49.3years. The series included 12 TFND, two HT, and 12 follicular adenomas (11 out of 12 were oncocytic adenomas). Twenty-four out of 26 underwent total thyroidectomy. In 24 out of 26 cases, the entire lobes and parenchyma were included and serial cuts at multiple levels were performed in cases with PB but without any evidence of malignancy. Even though the detection of PB is associated with a malignant thyroid lesion, especially PTC and its subtypes, our multi-institutional series showed that in a minority PB can be found in a variety of benign thyroid lesions. Evaluation of the entire thyroid parenchyma at multiple levels is mandatory to exclude sub-centimeter papillary thyroid carcinoma.

Hyperthyroïdie : diagnostic et suivi

AbstractHyperthyroidism is defined by thyroid hormones hyperproduction leading to clinical signs of thyrotoxicosis. It mainly results from thyroid primary hyperfunction due to either hyperstimulation by activating anti-TSH receptor antibodies (TRAK) in Graves’ disease, or to hyperfunction of one or more lesions of the thyroid parenchyma in nodular pathology. Positive diagnosis relies on clinical examination, scintigraphy, and biology. Biological investigations are based on a decreased serum TSH. A TSH between 0.1 -0.4 mIU/L will be checked at six weeks. To any TSH below 0.1 mIU/L or any TSH confirmed between 0.1 - 0.4 mIU/L, the addition of fT4 assay allows the distinction between proven hyperthyroidism (fT4 increased), and sub-clinical hyperthyroidism (normal fT4) a situation in which fT3 assay can be helpful to establish T3 hyperthyroidism The etiological diagnosis is essentially based on the TRAK measurement, whose positivity establishes Graves’ disease diagnosis, palpation and thyroid scintigraphy. Hyperthyroidism can be treated medically starting with synthetic antithyroid drugs (ATS), then with iratherapy or surgery, depending on the etiology. ATS efficiency will be biologically assessed following fT4 every 3-6 weeks, then monitoring TSH every 2-4 months after fT4 normalization. Treatment with ATS requires a specific biological follow up (hCG, WBC, ASAT, ALAT) to detect any complication.

Ultrasound scanning in diagnosing primary thyroid lymphoma.

This study aimed to summarize the clinical manifestations and ultrasound characteristics of primary thyroid lymphoma (PTL) and explore the key aspects in the process of diagnosing PTL. We conducted a retrospective analysis of the clinical and ultrasound features of 11 patients with PTL who were admitted to Shandong Provincial Third Hospital, China, between May 2009 and August 2023. The pathology was confirmed in all cases through an ultrasound-guided core needle biopsy or surgical resection. The mean age of the 11 patients was 64.45±9.85 years. In six patients, the main clinical manifestation was a palpable mass in the neck, five of whom had a significant increase in the size of the mass within 3 months to 2 years. Eleven patients had coexisting Hashimoto's thyroiditis (HT). Three patients were diagnosed as having diffuse-type PTL, wherein the ultrasound showed enlargement of the affected thyroid gland with diffusely uneven hypoechoic parenchyma. In 7 patients with nodular type PTL and 1 case of mixed type PTL, the ultrasonographic features of the nodular lesions were of irregular morphology and yet had distinct borders, and only 1 case had gross calcification. There were 7 cases of hypoechoic lesions (7/11 cases, 63.6%), 9 cases where the lesions had linear echo chains (9/11 cases, 81.8%), and 10 cases (90.9%) where there was echogenic enhancement posterior to the lesion. In elderly patients with HT, the thyroid volume increases significantly in a short period of time and symptoms associated with compression in the neck region appear. The ultrasound characteristics were extremely hypoechoic lesions in the thyroid parenchyma, with more linear echo chains visible inside, accompanied by posterior echo enhancement. When encountering such presentations, physicians must consider the possibility of PTL. Performing a core needle biopsy in cases that raise suspicion can reduce the incidence of misdiagnosis.

Thyroid hemiatrophy associated with papillary thyroid carcinoma.

The present study aimed to investigate CT imaging features, pathological findings, and prognosis in patients with thyroid hemiatrophy (THA) associated with papillary thyroid carcinoma (PTC). This retrospective study included 225 patients with histopathologically proven PTC treated by surgical resection who underwent preoperative CT scanning. On CT images, THA was defined as thyroid parenchymal hemiatrophy on the ipsilateral side of PTC. CT findings, overall survival, and disease-free survival were compared between patients with and without THA. Pathological findings were also assessed in PTCs with and without THA. THA was observed in 35 of 225 (16%) patients with PTC. Atrophic thyroid parenchyma was observed in the right lobe of 20 patients (57%) and in the left lobe of the remaining 15 patients (43%). With respect to the solid components within PTCs, contrast-enhanced CT attenuation (114.2 ± 18.2 vs. 126.7 ± 31.3 HU; p < 0.05) and CT attenuation change for contrast-enhanced CT minus unenhanced CT (60.2 ± 18.1 vs. 72.3 ± 31.0 HU; p < 0.05) were significantly lower in PTCs with THA than in those without THA. Histopathologically, almost all PTCs with THA (97%) had keloid-like collagen, which is broad bundles of hypocellular collagen with bright eosinophilic hyalinization, typically observed in keloid. However, no significant differences were observed in the prognosis between the two groups. THA was occasionally observed in patients with PTC. Weak contrast-enhancement was distinct characteristic of PTC patients with THA, which is probably caused by keloid-like collagen.

Intrathyroidal Parathyroid Adenoma.

Intrathyroidal parathyroid adenoma is a rare anomaly with an incidence of 1.4-6%. A cause of failure in the therapeutic management of hyperparathyroidism is the ectopic localization of the adenoma, particularly intrathyroidal. This is the case of a 51-year-old patient with no particular pathological history who presented with neck pain and whose clinical examination revealed a goiter. Parathyroid myocardial perfusion imaging (MIBI) scintigraphy revealed an elective MIBI-fixing focus with an upper left polar projection compatible with a parathyroid origin. A left loboishmectomy was performed. Anatomopathological study showed a parathyroid adenoma associated with dystrophic thyroid parenchyma, with no obvious histological signs of malignancy. Post-therapeutic laboratory work-up was normalized. Parathyroid adenoma, intrathyroidal, is an uncommon lesion but may be responsible for therapeutic failure in hyperparathyroidism. MIBI parathyroid gland scintigraphy is the gold standard for the diagnosis of parathyroid ectopy.

Protocolo diagnóstico y tratamiento del nódulo tiroideo

A thyroid nodule consists of the growth of a thyroid lesion that is delimited and distinguished from the normal thyroid parenchyma. Its incidence is increasing due to the increase in imaging tests (incidental thyroid tumors), with no impact on thyroid cancer survival. A thyroid function test with a thyroid stimulating hormone (TSH) measurement should be performed, thus verifying nodule functionality. In addition, an initial approach should be made to the probability of malignancy via a thyroid ultrasound that categorizes each nodule according to the European Thyroid Imaging and Reporting Data System (EU-TIRADS), indicating the risk of malignancy and also the size at which a thyroid cytology (via fine-needle aspiration) should be performed. Cytology allows for classifying the nodules according to the Bethesda categories that will provide an estimate of the risk of malignancy, which will be of utmost importance when deciding on management (observation versus surgery).

Bocio y enfermedad nodular tiroidea

Goiter and thyroid nodular disease are very common conditions of the thyroid gland. Goiter refers to growth of the normal thyroid parenchyma and thyroid nodule when the growth is located in a delimited, distinguishable area of the normal parenchyma. Its etiology is diverse, although the etiopathogenesis is not entirely clear. There tend to be few symptoms and the diagnosis is usually made through incidental findings on imaging tests. When evaluating thyroid nodules, it is essential to conduct a glandular function analysis, with an initial screening by measuring thyroid stimulating hormone (TSH) and describing the gland and possible nodules by means of thyroid ultrasound. Ultrasonography allows for evaluating nodule characteristics and classifying them according to the risk of malignancy by means of EU-TIRADS. In case of asymptomatic goiter, observation and clinical monitoring can be carried out, reserving other interventions for cases with compression of neighboring structures. On the other hand, management of the nodules will depend on symptoms, EU-TIRADS ultrasound features, and the Bethesda histological classification (in case of puncture). Observation and ultrasound monitoring or an invasive approach can be chosen.

Ultrasonographic Findings of Thyroid Parenchymal Disease

Thyroid parenchymal disease is an inflammatory disease that occurs in the thyroid parenchyma due to autoimmunity or infection. The differential diagnosis of thyroid parenchymal disease is based on clinical manifestation, physical examination, and serological findings. However, ultrasonography of thyroid has also a role in the diagnosis of thyroid parenchymal disease. This review describes common findings of ultrasonography in each thyroid parenchymal disease.

Detection of malignant lesions in cytologically indeterminate thyroid nodules using a dual-layer spectral detector CT-clinical nomogram.

To evaluate the capability of dual-layer detector spectral CT (DLCT) quantitative parameters in conjunction with clinical variables to detect malignant lesions in cytologically indeterminate thyroid nodules (TNs). Data from 107 patients with cytologically indeterminate TNs who underwent DLCT scans were retrospectively reviewed and randomly divided into training and validation sets (7:3 ratio). DLCT quantitative parameters (iodine concentration (IC), NICP (IC nodule/IC thyroid parenchyma), NICA (IC nodule/IC ipsilateral carotid artery), attenuation on the slope of spectral HU curve and effective atomic number), along with clinical variables, were compared between benign and malignant cohorts through univariate analysis. Multivariable logistic regression analysis was employed to identify independent predictors which were used to construct the clinical model, DLCT model, and combined model. A nomogram was formulated based on optimal performing model, and its performance was assessed using receiver operating characteristic curve, calibration curve, and decision curve analysis. The nomogram was subsequently tested in the validation set. Independent predictors associated with malignant TNs with indeterminate cytology included NICP in the arterial phase, Hashimoto's Thyroiditis (HT), and BRAF V600E (all p < 0.05). The DLCT-clinical nomogram, incorporating the aforementioned variables, exhibited superior performance than the clinical model or DLCT model in both training set (AUC: 0.875 vs 0.792 vs 0.824) and validation set (AUC: 0.874 vs 0.792 vs 0.779). The DLCT-clinical nomogram demonstrated satisfactory calibration and clinical utility in both training set and validation set. The DLCT-clinical nomogram emerges as an effective tool to detect malignant lesions in cytologically indeterminate TNs.

Changes in the structural and functional state of the thyroid gland of small mammals when exposed to low-intensity chronic radiation.

The study gives a morphofunctional assessment of the state of the thyroid gland of tundra voles (Microtus oeconomus Pall.) in conditions of an increased radiation background (the Ukhta district of the Komi Republic (Russia) and the 30-km zone of the Chernobyl NPP), as well as in an experiment with chronic external gamma irradiation in the low dose range. The work summarizes the experience of more than 35 years of field and laboratory research. The authors have noted the high sensitivity of the thyroid gland to chronic radiation against the general irradiation of the organism both in natural conditions and in the experiment. The repeatability of the observed effects in voles from natural populations and the comparability of some effects with the morphological changes occurring in animals after exposure to ionizing radiation in the experiment indicates the radiation nature of these effects. The tundra voles living in conditions of increased radiation background have been identified for a greater variety of morphological rearrangements in the thyroid parenchyma than the experimental animals. The complex and ambiguous nature of the thyroid gland responses to radiation exposure indicates the possibility of a significant increase in the risk of negative effects of ionizing radiation in contrast with the expected results of biological effects' extrapolation from high to low doses.

Ultrasound and cytopathological characteristics of thyroid tumours of uncertain malignant potential - from diagnosis to treatment.

The latest World Health Organization (WHO) classification from 2022 distinguishes the division of low-risk thyroid neoplasms such as non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), follicular tumour of uncertain malignant potential (FT-UMP), and well-differentiated tumour of uncertain malignant potential (WDT-UMP). The final diagnosis is made postoperatively according to histopathologic results. The aim of the study was the assessment of ultrasonographic and cytopathological features of borderline lesions to predict low-risk tumours preoperatively and plan the optimal treatment for that group of patients. A total of 35 patients (30 women; 5 men), aged 20-81 years with a mean age of 49 years, were enrolled in the study. The study evaluated 35 focal lesions of the thyroid gland, classified as low-risk neoplasms according to the WHO 2022 classification: FT-UMP (n = 21), NIFTP (n = 7), and WDT-UMP (n = 7). Ultrasonographic features of nodules including contrast-enhanced ultrasound (CEUS) and elastography were assessed by 2 specialists, and the risk of malignancy was evaluated according to EU-TIRADS-PL classification. Of the 35 focal thyroid lesions, most were categorised as low or intermediate risk of malignancy according to EU-TIRADS-PL, with dominant category 3 [n = 13 (37.2%)] and category 4 [n = 15 (42.8%)]. High-risk category 5 was assessed in 7 lesions (20%). In cytopathology nodules were categorised as follows (Bethesda System TBSRTC 2023): Bethesda II (n = 4), Bethesda III (n = 2), Bethesda IV (n = 25), Bethesda V (n = 3), and Bethesda VI (n = 1). In the CEUS study, contrasting patterns dominated compared to the surrounding parenchyma, such as enhancement equal to the parenchyma (66.6%) or intense (28.5%), heterogeneous (61.9%), centripetal (42.8%), or diffuse (57.1%) with fast (33.3%) or compared to parenchyma contrast wash-in (42.8%) and its fast (33.3%) or comparable to thyroid parenchyma wash-out (52.3%). The study indicates that lesions with uncertain malignant potential typically present features suggesting low to intermediate risk of malignancy based on EU-TIRADS-PL classification, with dominant cytopathologic Bethesda IV category. However, 20% of lesions were assessed tas EU-TIRADS-PL category 5. Low-risk tumours, including NIFTP, FT-UMP, and WDT-UMP, require careful observation and monitoring post surgical treatment due to their potential for recurrence and metastasis. The preoperatively prediction of borderline tumour may play an important role in proper treatment and follow-up.

Evaluation of the thyroid gland vascularity during pregnancy using 2-dimensional color Superb Microvascular İmaging vascularization index technique

PurposeWe aimed to investigate maternal thyroid parenchymal vascularity with 2-dimensional color superb microvascular imaging vascularization index (2D-cSMIVI) levels and thyroid gland volume in the first, second and third trimesters. MethodsThis longitudinal prospective study was carried out with participants selected from 30 healthy asymptomatic pregnant women. Ultrasonography (US) for the thyroid gland was performed in each trimester. The vascularization index (VI) values obtained by manually drawing the contours of the thyroid parenchyma in the longutidinal plane, using the free region of interest (ROI) with 2DcSMIVI mode. VI values obtained in each trimester, thyroid hormone levels (TSH, T3, T4) and thyroid volumes were compared. ResultsWe have detected that thyroid gland vascularity increased significantly as pregnancy progresses. The mean VI values of thyroid gland in third trimester were significantly higher than first and second trimester (p < 0.001), and the mean VI values of the thyroid gland in the second trimester were significantly higher than first trimester (p < 0.001). During pregnancy, we detected the increase in VI values, TSH levels and thyroid gland volumes. ConclusionMaternal thyroid gland gray scale findings, parenchymal vascularization, thyroid volumes should be evaluated routinely for the healthy fetal development. 2D-cSMIVI method allows us to evaluate vascularization with quantitative numerical values objectively. We have detected that the VI values and volume of the thyroid gland increases as pregnancy progresses. In the complex situation of pregnancy process, the thyroid gland can be evaluated quantitatively with SMI method effectively.

Clinicopathological Evaluation of Papillary Thyroid Microcarcinoma.

Clinicians sometimes encounter papillary thyroid microcarcinoma (PMC) that is less than 10 mm, associated with lymph node metastasis. In this study, we assessed PMC clinicopathologically to clarify risk factors for poor prognosis. Fifty-one patients who underwent thyroid surgery at Aichi Medical University from September 2009 to October 2016 were included. Patients were divided into two groups, pEX-positive (23 patients) and pEX-negative (28 patients), based on the pathological finding of thyroid capsule invasion. The former indicates that the tumor infiltrated the thyroid capsule and spreadto the neighboring tissue, and the latter indicates no capsule invasion. We analyzed factors such as patient characteristics, pathological findings, and serum levels of thyroid hormones in the two groups. No statistical differences were observed between the two groups in gender distribution or age at surgery. Preoperative cancer diagnoses were established for more patients in the pEX-positive group than in the pEX-negative group (n = 21 and 14, respectively; P = 0.004). The mean (±SD) pathological tumor diameter was 5.42 ± 2.77 in the pEX-negative group and 8.32 ± 1.61 in the pEX-positive group (P < 0.001). No significant differences in preoperative serum levels of free T3, free T4, thyroid-stimulating hormone, or thyroglobulin were observed between the two groups. The odds ratio for node positivity in tumors invading thyroid capsules (pEX-positive) compared to those with no capsule invasion (pEX-negative) was 13.20 (95% confidence interval, 3.45-50.42). Immunohistological staining for phosphatase and tensin homolog deleted from chromosome 10 (PTEN) and Akt (protein kinase B) revealed the facilitation of PTEN and suppression of Akt, which might indicate downregulation of the phosphoinositide 3-kinase-Akt (PI3K-Akt) cascade. In general, the prognosis of PMC is favorable. However, the prognosis is less favorable in patients with nodal metastasis or extrathyroidal invasion. It is controversial whether resection is required for proven PMCs. For PMCs associated with extrathyroidal invasion, regional lymph node resection with lobectomy should be performed due to the high risk for lymphatic spread. There might be a possibility that the natural progression of PMC seems to be controlled by the facilitation of PTEN. However, a tumor in the lateral peripheral region of the thyroid parenchyma might be associated with capsule invasion followed by lymphatic spread.

Principles and features of ultrasound hypoechogenicity in diffuse thyroid pathology.

For different thyroid diseases and hormonal metabolism, ultrasound (US) of the thyroid gland reveals hypoechogenicity. Despite the direct correlation of hypoechogenicity with the levels of thyroid-stimulating hormone and antibodies of thyroid peroxidase and thyroglobulin, ~20% of this correlation is inconsistent, thus restricting the comprehensive utilisation of this valuable diagnostic sign. Thus, it is necessary to investigate the additional circumstances affecting the extent and features of the US hypoechogenicity of the thyroid gland. The technique for assessing thyroid hypoechogenicity was based on the basic setting of the US mode and visual assessment in percentage of gray relative to a gradient gray scale. Doppler mode was used. US data were compared with the results of hormonal and immune blood tests. The study contains the morphofunctional basis of the various US hypoechogenicities detected in the diffuse pathology of the thyroid gland has been presented, and the principles and probable mechanisms of widespread and segmental hypoechogenicity formation are disclosed for the first time. Furthermore, a mandatory Doppler involving thyroid parenchyma blood flow intensity and peak systolic blood velocity of thyroid arteries, which indicates the magnitude of neurovegetative influence, has been suggested. The results of the study shows revealed that the evaluation of the importance and features of US hypoechogenicity in various diffuse thyroid pathologies is probably based on a single system involving neurohumoral regulation, segmental arrangement and compensatory reserve state of the gland parenchyma.