The Impact of BRAF V600E Mutation Allele Frequency on the Histopathological Characteristics of Thyroid Cancer

BACKGROUND

A BRAF V600E mutation in papillary thyroid cancer (PTC) has been shown to be associated with aggressive behavior. Nevertheless, not all BRAF V600E PTCs behave aggressively. Allele frequency (AF) is the number of mutated molecules divided by the total number of wild-type molecules at a specific location in the genome. The relationship between BRAF V600E AF and the histopathological features of thyroid malignancies is not well understood. We hypothesized that the BRAF V600E AF will correlate directly with aggressive histopathological behavior. The aim of this study was to examine this relationship.

METHODS

A retrospective chart review was performed for patients treated for BRAF V600E thyroid malignancies from 2019 to 2022 at McGill University tertiary care hospitals (n = 317). Patients with BRAF V600E-positive malignancies that included information on AF were included (n = 44). The correlation between AF and tumor histopathological features was analyzed.

RESULTS

Out of the 44 nodules with a BRAF V600E mutation, those with aggressive features of PTC had a mean AF of 25.8%, which was significantly higher than the non-aggressive group with a mean AF of 10.25% (p = 0.020). Additionally, there was a statistically significant difference in mean AF between patients with a positive sentinel LN (29%) and those with a negative sentinel LN (17.8%) (p = 0.021). Classical PTC was present in 29.5% (13/44) of nodules, with a mean AF of 15.6%. The tall cell subtype was found in 64% (28/44) of nodules, with a mean AF of 23%. Solid and hobnail subtypes were less common in this study, and there was no statistically significant relationship between AF and histopathological subtypes (p = 0.107). Nodules smaller than 1cm had a mean AF of 13.3%, while nodules ranging from 1 2cm had a mean AF of 20.6%, and those larger than 2cm had a mean AF of 27.7%. However, no statistical difference was observed between AF and nodule size (p = 0.160).

CONCLUSION

In this study, BRAF V600E mutations in conjunction with AF help to determine whether thyroid malignancies will display aggressive behavior. This pre-operative finding can help thyroid specialists to determine the extent of thyroidectomy and whether lymph node dissection is required.

Coexisting Molecular Alterations Increase the Risk of Malignancy in Thyroid Nodules with Copy Number Alterations

Molecular mutations and alterations play a role in thyroid tumorigenesis. Different alterations are associated with different clinical and pathological characteristics. Copy number alterations (CNAs) are known to be present in some thyroid tumors; however, their idiosyncratic clinicopathological implications are not yet well elucidated. A retrospective chart review was performed to identify patients with CNAs on pre-operative molecular testing results who subsequently underwent surgical treatment between January 2016 and April 2022 at McGill University teaching hospitals. Of the 316 patients with thyroid nodules who opted for molecular testing with ThyroSeqV3 followed by surgery, 67 (21.2%) nodules were positive for CNAs, including 23 Bethesda III, 31 Bethesda IV, 12 Bethesda V and 1 Bethesda VI nodules. On surgical pathology, 29.9% were benign and 70.1% were malignant or non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). Among those that were malignant/NIFTP, 17.02% were considered to be aggressive cancers. The presence of other molecular alterations was found to be an independent predictor of malignancy in multivariate analysis (OR = 5.087, 95% C.I. = 1.12-23.04, p = 0.035). No unique factor was correlated with aggressiveness; however, CNA-positive thyroid nodules that were associated with high-risk mutations such as BRAF V600E, TP53, NTRK1/3 fusion, or PTEN mutation with high allele frequency (AF) ended up being aggressive cancers. Most of the CNA-positive thyroid nodules resulted in follicular patterned tumors in 41 (65.2%) cases and oncocytic tumors in 20 (29.9%) cases. This study demonstrates that 70.1% of surgically resected thyroid nodules with CNAs were malignant/NIFTP. Most CNA-positive thyroid nodules were either oncocytic patterned tumors or follicular patterned tumors. Furthermore, CNA-positive thyroid nodules were more likely to be malignant if they were associated with other molecular alterations or mutations.

Molecular Testing for Thyroid Nodules: The Experience at McGill University Teaching Hospitals in Canada

In the past few decades, molecular characterization of thyroid cancer has made significant progress and is able to identify thyroid-cancer-related molecular markers that can then be applied clinically for improved decision making. The aim of this review is to provide a general overview about the molecular markers (mutations and alterations) of thyroid cancers, present several molecular tests, and discuss the clinical applications of identifying these markers supported by the clinical experience of several high-volume thyroid cancer specialists at the McGill university hospitals in Montreal, Canada. Our group experience showed that molecular testing can reclassify more than half of the patients with indeterminate thyroid nodules (Bethesda III and IV) into benign and spare these patients from unnecessary diagnostic surgery. Furthermore, it can help optimize the initial management in thyroid cancers with no evidence of high risk of recurrence of disease preoperatively. While routine molecular testing is not firmly established for thyroid FNA specimens that are suspicious or positive for malignancy (Bethesda V and VI), knowledge of a thyroid nodule’s molecular risk group profile in such cases, together with its clinical and radiologic features, can help select the optimal surgical options (lobectomy versus upfront total thyroidectomy and central neck dissection), as demonstrated by our studies.

A Rare Case of Thyroid Metastasis Secondary to Hidden Undiagnosed Lung Adenocarcinoma

The majority of thyroid lesions are primary in origin while secondary metastases to thyroid are considered a rare incidence. However, presentation of such cases with no signs of lung cancer can be extremely challenging to diagnose. Here, we present a 64-year-old man, an ex-smoker of 70 pack-years, who presented with a complaint of hoarseness of voice with associated dyspnea, choking episodes, weight loss, and hemoptysis. With no investigation abnormalities indicating lung adenocarcinoma, he was transferred to the Otolaryngology Department as being suspicious of thyroid cancer. A laryngoscopy demonstrated an immobile right vocal cord and pooling of secretions while a computed tomography (CT) scan showed a right thyroid lobe nodule, upper mediastinal lymphadenopathy, and pleural effusion. The patient underwent a total thyroidectomy. Biopsies from the lymph nodes and lung were obtained, and all demonstrated lung adenocarcinoma. Thus, a diagnosis of primary lung adenocarcinoma with thyroid and mediastinal lymph nodes metastases was established. Despite being a rare clinical presentation, thyroid metastasis should be considered and evaluated for a primary origin according to the associated clinical history and presentation.

Rare presentation of metastatic renal cell carcinoma to thyroid gland: A case report

Introduction

Renal cell carcinoma is known to cause metastasis to unusual sites, but metastasis to the thyroid gland is a rare occurrence, not only that, but 20 years after complete recovery is almost nonexistent.

Case presentation

We are presenting here a case of 79-year-old female who presented to us for asymptomatic progressive thyroid nodule. She had history of right nephrectomy for renal cell carcinoma 20 years ago. Ultrasound guided fine needle aspiration biopsy (FNAB) of the thyroid was non-diagnostic. Total thyroidectomy of the patient was performed, and histopathological evaluation of the specimen revealed the swelling to be of metastatic in nature secondary to renal cell carcinoma.

Discussion

Despite thyroid metastasis being rare, FNAB can prove to be useful tool for diagnosis of thyroid tumors and metastases and can be inconclusive in some cases. Therefore, immunohistochemistry can prove beneficial in diagnosis such cases.

Conclusion

The diagnosis of renal cell carcinoma metastasis is made after immunohistochemical evaluation of the thyroidectomy specimen with thyroidectomy proving to be the modality of treatment for such cases with no further radiation therapy and a yearly follow up plan to screen for other lesions.

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Renal cell carcinoma is one of the most common malignany to metastasize to thyroid.

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Metastatic etiology should always be considered in thyroid nodule patient with history of renal cell carcinoma.

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Diagnosis is mainly by immunohistochemical analysis.

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Surgery has a significant mortality benefit.

Hoarseness of Voice as a Rare Presentation of Tuberculosis: A Case Report Study

BACKGROUND:

Having hoarseness of voice as the first clinical manifestation of tuberculosis is rare. This atypical presentation causes some confusion since other more common conditions, such as laryngeal carcinoma, present similarly and might require more invasive tests to confirm the diagnosis.

CASE PRESENTATION:

A 38-year-old male presented to the otorhinolaryngology clinic with a four-month history of change in voice. Laryngoscopy demonstrated a right glottic mass, raising suspicion of laryngeal cancer. The computed tomography showed a mass and incidental finding of opacities in lung apices. Chest x-ray demonstrated findings suggestive of tuberculosis. Polymerase chain reaction and culture of sputum samples confirmed the diagnosis and the patient was started on anti-tuberculosis treatment.

CONCLUSION:

Despite accounting for only 1% of pulmonary tuberculosis cases and having a similar presentation to laryngeal carcinoma, we recommend considering laryngeal tuberculosis when evaluating hoarseness of voice in endemic areas.

Antenatal corticosteroids in the late preterm period: A prospective cohort study

OBJECTIVE

The study objective was to examine the effect of antenatal corticosteroids on the incidence of short-term neonatal morbidities in singletons born during the late preterm period.

STUDY DESIGN

This was a prospective cohort study of singleton gestations at risk of imminent delivery between 34 0/7 and 36 6/7 weeks. Short-term neonatal morbidities were compared between the corticosteroid exposed and non-exposed groups. The rates of Neonatal Morbidity Composite and Any Adverse Neonatal Morbidity were then compared between the two groups.

RESULTS

During the two-year study period, a total of 295 subjects were included. Of those, 74 were exposed to antenatal corticosteroids, while 221 cases constituted the non-exposed group. There was no statistically significant difference in the rate of Any Adverse Neonatal Morbidity (47.3% vs. 40.7% , p = 0.32) or the rate of Neonatal Morbidity Composite (34.4% vs. 37.8% , p = 0.59) between the two groups. Additionally, there was no statistically significant difference in the rates of neonatal intensive care unit admission, respiratory distress syndrome, transient tachypnea of the newborn, hypothermia, and need for phototherapy.

CONCLUSION

Administration of antenatal corticosteroids to parturients at risk of imminent delivery during the late preterm period does not appear to reduce short-term neonatal morbidities.

Characterization of influenza outbreaks in Lebanon during the 2013/14 and 2014/15 seasons

Despite the significant burden of influenza outbreaks, active disease monitoring has been largely absent in the Middle East, including Lebanon. In this study we characterized influenza virus in 440 nasopharyngeal swabs collected from patients with acute respiratory infections during two influenza seasons in Lebanon. Influenza A(H3N2) was dominant in the 2013/14 season while the A(H1N1)pdm09 and B/Yamagata strains were most prevalent in the 2014/15 season. All tested isolates were susceptible to 4 neuraminidase inhibitors (oseltamivir, zanamivir, peramivir and laninamivir). Genetic analysis of the haemagglutinin gene revealed multiple introductions of influenza viruses into Lebanon from different geographic sources during each season. Additionally, large data gaps were identified in the Middle East region, as indicated by the lack of current influenza sequences in the database from many countries in the region.

Optimization of a metformin effervescent floating tablet containing hydroxypropylmethylcellulose and stearic acid

This study optimizes the composition of an effervescent floating tablet (EFT) containing metformin hydrochloride (M) regarding tablet hardness (H), time to dissolve 60% of the embedded drug (t60%), and buoyancy, the floating lag time (FLT). A simplex lattice experimental design has been used comprising different levels of hydroxypropylmethylcellulose (HPMC), stearic acid (SA), sodium bicarbonate (SB) as tablet matrix components, and hardness (H), t60%, FLT as response variables. Two models have been applied to decide which composition will result in Fickian diffusion or in overlapping of two dissolution mechanisms, diffusion and matrix erosion. Three of EFT showed the two dissolution mechanisms but most of EFT showed Fickian diffusion only. Checking the experimental response by a linear, quadratic, special cubic and cubic model using multivariate regression analysis resulted in best fit for the cubic model. Overlaying the results for the cubic model under constraints defined shows the domain of accepted values of response variables. The optimized EFT shall have been included HPMC between 15.6% and 24.2%, SA between 12.8 and 15.6% and SB between 16.1% and 17.5%. The result of this study has been critically evaluated considering analogous EFT described in literature.