LBSAT145 Localizing The "Difficult" Parathyroid Tumor

Background

The identification of parathyroid tumor(s) in patients with persistent/recurrent primary hyperparathyroidism (PHPT) is critical for a successful re-operative surgery. We describe our experience with invasive studies for parathyroid tumor localization and provide follow-up data regarding our experience with selective arterial hypocalcemic stimulation with central venous sampling (SAHSCVS).

Methods

We identified patients who underwent pre-operative invasive testing for localization of parathyroid tumor at our center. At our center, only PHPT patients with history of prior neck surgery without definitive findings on non-invasive testing (sestamibi, ultrasound, CT, MRI) proceed to invasive studies. The result of each invasive localization study (arteriogram, SAHSCVS and selective venous sampling (SVS)) was categorized as true-positive (TP), false-positive (FP) and false-negative (FN) based on biochemical outcome.

Results

Ninety-five patients with 98 tumors underwent invasive testing for parathyroid tumor localization. All but one had recurrent disease. Sixty-two patients (65%) had "apparently sporadic" PHPT, 19/95 (20%) had MEN1, three had parathyroid cancer (PC) and the remaining had other heritable forms of PHPT. Median age of index PHPT presentation was 47 [34-58] years. Of 87 tumors with available operative details, 66 (76%) were in the neck, 20 in the mediastinum (23%), and one in the forearm at site of prior autograft. Seventy-two (83%) showed hyperplasia or hypercellularity on histology. Median tumor size was 5 mm. Arteriogram, SAHSCVS and SVS accurately localized the tumor in 47/90 (52%), 54/90 (60%) and 49/61 (80%) tumors respectively. Positive Predictive Value of arteriogram, SAHSCVS and SVS was 47/50 (94%), 55/64 (86%) and 49/59 (83%) respectively. Both sensitivity and PPV showed no significant difference between patients with MEN1+PC vs. others. Among the 54 tumors accurately localized by SAHSCVS, SVS was performed in 29/54 with complete concordance. Twenty-seven tumors (30%) were missed (FN) on SAHSCVS, of these 14/25 (56%) were also missed on arteriogram. Nevertheless, 16/20 (80%) localized accurately on subsequent SVS. SAHSCVS was FP in localizing nine tumors - seven (78%) of these did not show a blush on arteriogram. All pre-operative localizing studies were unrevealing in 9/98 presentations (10%).

Conclusion

Patients with difficult to localize parathyroid tumors have clinical features suspicious for germline-predisposition forms of PHPT indicated by recurrent disease, hyperplastic glands, and age of index presentation. SAHSCVS can be a useful adjunct in patients who require invasive localization. 90% of these tumors are localized with combination of current non-invasive and invasive testing. AcknowledgementThis research is supported by the Intramural Research Program of NIDDK, NCI and NIH Clinical Center.

Presentation: Saturday, June 11, 2022 1:00 p.m. - 3:00 p.m.

HEREDITARY ENDOCRINE TUMOURS: CURRENT STATE-OF-THE-ART AND RESEARCH OPPORTUNITIES: MEN1-related pancreatic NETs: identification of unmet clinical needs and future directives

The PanNET Working Group of the 16th International Multiple Endocrine Neoplasia Workshop (MEN2019) convened in Houston, TX, USA, 27-29 March 2019 to discuss key unmet clinical needs related to PanNET in the context of MEN1, with a special focus on non-functioning (nf)-PanNETs. The participants represented a broad range of medical scientists as well as representatives from patient organizations, pharmaceutical industry and research societies. In a case-based approach, participants addressed early detection, surveillance, prognostic factors and management of localized and advanced disease. For each topic, after a review of current evidence, key unmet clinical needs and future research directives to make meaningful progress for MEN1 patients with nf-PanNETs were identified. International multi-institutional collaboration is needed for adequately sized studies and validation of findings in independent datasets. Collaboration between basic, translational and clinical scientists is paramount to establishing a translational science approach. In addition, bringing clinicians, scientists and patients together improves the prioritization of research goals, assures a patient-centered approach and maximizes patient involvement. It was concluded that collaboration, research infrastructure, methodologic and reporting rigor are essential to any translational science effort. The highest priority for nf-PanNETs in MEN1 syndrome are (1) the development of a data and biospecimen collection architecture that is uniform across all MEN1 centers, (2) unified strategies for diagnosis and follow-up of incident and prevalent nf-PanNETs, (3) non-invasive detection of individual nf-PanNETs that have an increased risk of metastasis, (4) chemoprevention clinical trials driven by basic research studies and (5) therapeutic targets for advanced disease based on biologically plausible mechanisms.

Prognostic factors for the outcome of nonfunctioning pancreatic neuroendocrine tumors in MEN1: a systematic review of literature

Metastatic duodenopancreatic neuro-endocrine tumors (dpNETs) are the most important disease-related cause of death in patients with multiple endocrine neoplasia type 1 (MEN1). Nonfunctioning pNETs (NF-pNETs) are highly prevalent in MEN1 and clinically heterogeneous. Therefore, management is controversial. Data on prognostic factors for risk stratification are limited. This systematic review aims to establish the current state of evidence regarding prognostic factors in MEN1-related NF-pNETs. We systematically searched four databases for studies assessing prognostic value of any factor on NF-pNET progression, development of distant metastases, and/or overall survival. In- and exclusion, critical appraisal and data-extraction were performed independently by two authors according to pre-defined criteria. Thirteen studies (370 unique patients) were included. Prognostic factors investigated were tumor size, timing of surgical resection, WHO grade, methylation, p27/p18 expression by immunohistochemistry (IHC), ARX/PDX1 IHC and alternative lengthening of telomeres. Results were complemented with evidence from studies in MEN1-related pNET for which data could not be separately extracted for NF-pNET and data from sporadic NF-pNET. We found that the most important prognostic factors used in clinical decision making in MEN1-related NF-pNETs are tumor size and grade. NF-pNETs <2 cm may be managed with watchful waiting, while surgical resection is advised for NF-pNETs ≥2 cm. Grade 2 NF-pNETs should be considered high risk. The most promising and MEN1-relevant avenues of prognostic research are multi-analyte circulating biomarkers, tissue-based molecular factors and imaging-based prognostication. Multi-institutional collaboration between clinical, translation and basic scientists with uniform data and biospecimen collection in prospective cohorts should advance the field.

Molecular Signatures and Their Clinical Utility in Pancreatic Neuroendocrine Tumors

Pancreatic neuroendocrine tumors (PNETs) are classified based on their histologic differentiation and proliferative indices, which have been used extensively to determine prognosis. Advances in next-generation sequencing and other high-throughput techniques have allowed researchers to objectively explore tumor specimens and learn about the genetic alterations associated with malignant transformation in PNETs. As a result, targeted, pathway-specific therapies have been emerging for the treatment of unresectable and metastatic disease. As we continue to trial various pharmaceutical products, evidence from studies using multi-omics approaches indicates that clinical aggressiveness stratifies along other genotypic and phenotypic demarcations, as well. In this review, we explore the clinically relevant and potentially targetable molecular signatures of PNETs, their associated trials, and the overall differences in reported prognoses and responses to existing therapies.

Modification of the Surgical Strategy for the Dissection of the Recurrent Laryngeal Nerve Using Continuous Intraoperative Nerve Monitoring

BACKGROUND

The aim of this study was to describe first experiences and changes in management using continuous intraoperative neuromonitoring (C-IONM) in thyroid and parathyroid surgery.

METHOD

Retrospective analysis of patients who underwent surgery with C-IONM since 2012. Surgical maneuvers were modified when electrophysiologic events occurred. Patients with persistent loss of signal (LOS) underwent postoperative laryngoscopy.

RESULTS

One hundred and one patients (of 1586 neck surgeries) were included and 19 had events: In 13 these were temporary (resolved before end of surgery) and led to intraoperative modifications in surgical approach; in all cases traction was released, and in 8, recurrent laryngeal nerve (RLN) approach was changed [superior approach (2), inferior approach (2), both (4)]. Six patients had persistent LOS (5.9%, present at end of procedure), with RLN palsy (RLNP) on postoperative day 1: In three, LOS occurred at electrode placement on the vagus nerve, leading to distal placement of the electrode allowing ipsilateral dissection under continuous monitoring; all three had complete recovery at 6 months. In the three other patients, LOS occurred on the RLN: one probable thermal, one traction lesion and one accidental section of the anterior RLN branch. The RLN recovered within 6 months in two patients, and in the third, RLNP persisted after 6 months (1/101 = 1%).

CONCLUSION

C-IONM provides real-time evaluation of the RLN function, allowing for adaptation of surgical maneuvers to prevent RLNP. It seems particularly useful in difficult cases like redo neck surgery, invasive thyroid cancer and intrathoracic or large goiter. Care should be given at electrode placement on the vagus nerve.

Identification of Differential Transcriptional Patterns in Primary and Secondary Hyperparathyroidism

CONTEXT

Hyperparathyroidism is associated with hypercalcemia and the excess of parathyroid hormone secretion; however, the alterations in molecular pattern of functional genes during parathyroid tumorigenesis have not been unraveled. We aimed at establishing transcriptional patterns of normal and pathological parathyroid glands (PGs) in sporadic primary (HPT1) and secondary hyperparathyroidism (HPT2).

OBJECTIVE

To evaluate dynamic alterations in molecular patterns as a function of the type of PG pathology, a comparative transcript analysis was conducted in subgroups of healthy samples, sporadic HPT1 adenoma and hyperplasia, and HPT2.

DESIGN

Normal, adenomatous, HPT1, and HPT2 hyperplastic PG formalin-fixed paraffin-embedded samples were subjected to NanoString analysis. In silico microRNA (miRNA) analyses and messenger RNA-miRNA network in PG pathologies were conducted. Individual messenger RNA and miRNA levels were assessed in snap-frozen PG samples.

RESULTS

The expression levels of c-MET, MYC, TIMP1, and clock genes NFIL3 and PER1 were significantly altered in HPT1 adenoma compared with normal PG tissue when assessed by NanoString and quantitative reverse transcription polymerase chain reaction. RET was affected in HPT1 hyperplasia, whereas CaSR and VDR transcripts were downregulated in HPT2 hyperplastic PG tissue. CDH1, c-MET, MYC, and CaSR were altered in adenoma compared with hyperplasia. Correlation analyses suggest that c-MET, MYC, and NFIL3 exhibit collective expression level changes associated with HPT1 adenoma development. miRNAs, predicted in silico to target these genes, did not exhibit a clear tendency upon experimental validation.

CONCLUSIONS

The presented gene expression analysis provides a differential molecular characterization of PG adenoma and hyperplasia pathologies, advancing our understanding of their etiology.

Impact of near-infrared angiography on the quality of anatomical resection during video-assisted thoracic surgery segmentectomy

Background

The aim of the present study was to assess the impact of near-infrared angiography in guiding intraoperatively sublobar anatomical resection by video-assisted thoracic surgery (VATS).

Methods

We retrospectively analyzed data from 67 patients who underwent segmentectomy by VATS from November 2014 to November 2017 at the University Hospitals of Geneva, Switzerland. The need to modify arterial or parenchymal resection based on intraoperative near-infrared imaging was considered the primary study outcome.

Results

A total of 67 patients (28 men, 39 women, mean age 66±10 years) underwent anatomical pulmonary segmentectomy by VATS. Histological analysis revealed a primary lung tumor in 59 patients. The mean ± standard deviation (SD) operation time was 154±51 minutes. Identification of the intersegmental plane (ISP) with near-infrared angiography was achieved in 88% of patients and led to modification of the resection during segmentectomy in 7 patients (10%), avoiding inappropriate resection; 2 patients had distant tumor recurrences (3%).

Conclusions

Near-infrared angiography during VATS segmentectomy is effective for identifying ISPs, with respect to the oncological margins, as well as for correcting the anatomical resection.

A reappraisal of vascular anatomy of the parathyroid gland based on fluorescence techniques

Identification of the parathyroid glands (PGs) during thyroid surgery may prevent their inadvertent surgical removal and prevent postoperative hypoparathyroidism. However, identification of the PGs does not guarantee their function, and their vascular supply needs to be preserved as well. The recent introduction of intraoperative indocyanine green (ICG) fluorescent angiography of the PGs during thyroid surgery allows for the appraisal of the vascular anatomy and evaluation of PG function. The use of this tool could lead to a significant reduction in the rate of postoperative hypoparathyroidism, as it allows surgeons to adapt their surgical technique for the preservation of the PGs. ICG fluorescent angiography is currently the only available real-time tool to assess the vascular blood supply of each individual PG intraoperatively and can thus assist surgeons in their decision-making. Herein, we review the relevant literature.

The future: surgical advances in MEN1 therapeutic approaches and management strategies

Multiple endocrine neoplasia type 1 (MEN1) is a hereditary autosomal dominant disorder associated with numerous neuroendocrine tumors (NETs). Recent advances in the management of MEN1 have led to a decrease in mortality due to excess hormones; however, they have also led to an increase in mortality from malignancy, particularly NETs. The main challenges are to localize these tumors, to select those that need therapy because of the risk of aggressive behavior and to select the appropriate therapy associated with minimal morbidity. This must be applied to a hereditary disease with a high risk of recurrence. The overall aim of management in MEN1 is to ensure that the patient remains disease- and symptom-free for as long as possible and maintains a good quality of life. Herein, we review the changes that occurred in the last 20 years in the surgical management of MEN1-associated functional and non-functional pancreatico-duodenal NETs and thymic and bronchial NETs.

The search for preoperative biomarkers for thyroid carcinoma: application of the thyroid circadian clock properties

Accumulating evidence suggests that alterations in the molecular clocks underlying the circadian time-keeping system might be connected to changes in cell cycle, resulting in oncogenic transformation. The hypothalamic–pituitary–thyroid axis is driven by a circadian clock at several levels, with an endocrine feedback loop regulating thyroid-stimulating hormone. Changes in the expression levels of circadian and cell cycle markers may correlate with clinic-pathological characteristics in differentiated follicular thyroid carcinomas. Here we summarize recent advances in exploring complex regulation of the thyroid gland transcriptome and function by the circadian oscillator. We particularly focus on clinical implications of the parallel assessment of the circadian clock, cell-cycle and cell functionality markers in human thyroid tissue, which might help improving preoperative diagnostics of thyroid malignancies.

Acute pancreatitis after thoracic duct ligation for iatrogenic chylothorax. A case report

Background

To report the association between thoracic duct ligation and acute pancreatitis. The association between sudden stop of lymphatic flow and pancreatitis has been established in experimental models.

Case presentation

A 57-year-old woman operated for thymoma presented a iatrogenic chylothorax. After thoracic duct ligation, she presented an acute pancreatitis which resolved after conservative treatment. The chylothorax disappeared within 4 days of thoracic duct ligation.

Conclusions

This is the first report of acute pancreatitis following thoracic duct ligation. The pancreas and digestive tract should be assessed in symptomatic patients after thoracic duct ligation.

Electronic supplementary material

The online version of this article (doi:10.1186/s12893-017-0204-3) contains supplementary material, which is available to authorized users.

Oncocytic Adrenocortical Neoplasm with Concomitant Papillary Thyroid Cancer

Adrenal oncocytoma (AO) is an extremely rare adrenocortical neoplasm and little is known about its malignant potential, secretory properties, and hereditary origin. We present the case of a benign AO with concomitant incidentally found papillary thyroid cancer (PTC) and review similar cases in the literature. Immunohistochemistry and next-generation sequencing (NGS) were performed. A 66-year-old women was incidentally found to have a large, androgen-secreting right adrenal mass. ¹⁸F-Fluorodeoxyglucose positron emission tomography showed intense uptake (SUV_max 88.7) of this mass and found a hypermetabolic right thyroid mass. Open adrenalectomy was performed for this highly suspicious adrenal mass. Histopathology revealed benign AO that was BRAF^V600E negative, with low Ki-67, and no somatic mutation found on NGS. Thyroidectomy revealed invasive, BRAF^V600E-positive PTC. At 6 months follow-up, androgen levels returned to normal, and no recurrence was seen on imaging. To our knowledge, this is the first report of an androgen-secreting AO with concomitant PTC. Possibly the simultaneous discovery of two independent neoplasms was observed. In conclusion, this case highlights that care should be given to exclude concomitant neoplasms. Long-term and regular imaging with biochemical follow-up is warranted, since the outcome and clinical behavior of AO remains uncertain.

Aberrant origin of the inferior thyroid artery from the common carotid artery: a rare anatomical variation

We describe the case of a rare anatomical variant of the inferior thyroid artery (ITA) taking its origin directly from the common carotid artery (CCA) instead of the thyrocervical trunk (TCT). This anatomical feature exposes to risks of perioperative bleeding and nerve injuries when it is unrecognized by the surgeons. Knowledge of its existence may be helpful to reduce risks for the patient.

Neuroendocrine Tumor of the Pancreas as a Manifestation of Cowden Syndrome: A Case Report

CONTEXT

Germline mutations in the phosphatase and tensin homolog (PTEN) tumor suppressor gene are found in the majority of patients with Cowden syndrome (CS), who have an increased risk of breast, thyroid, and endometrial cancer. According to our current understanding of genetic changes in the PTEN gene and the resultant phenotypic features of CS, pancreatic neuroendocrine tumors (NETs) are not considered part of the clinical spectrum of CS.

CASE DESCRIPTION

We report a unique case of an advanced NET of the pancreas in a patient with CS. The germline DNA sequencing confirmed the clinical diagnosis of CS and revealed a PTEN mutation c.697C→T (p.R233*) causing a premature stop codon in exon 7. The tumor DNA sequencing showed no loss of heterozygosity or any copy number changes and no other deleterious genetic alterations, including those commonly mutated in sporadic pancreatic NETs: MEN1, ATRX, DAXX, TP53, and genes involved in the mammalian target of rapamycin pathway. In addition, the high-throughput transcriptome analyzed by RNA-seq did not reveal any missed genetic alterations, aberrant splicing variants, gene fusions, or gene expression alterations. The immunohistochemical staining of the tumor for PTEN revealed an abnormal, uniformly strong cytoplasmic staining of tumor cells with virtually absent nuclear staining.

CONCLUSION

The results from genetic testing and histopathological techniques used to confirm CS diagnosis and characterize this unusual tumor tempted us to believe that in this case, the pancreatic NET was not a sporadic malignancy that occurred by coincidence, but rather represented a new entity in the spectrum of malignancies associated with CS.

Systematic use of recurrent laryngeal nerve neuromonitoring changes the operative strategy in planned bilateral thyroidectomy

BACKGROUND

One of the worst complications in thyroid surgery is bilateral recurrent laryngeal nerve paralysis, which can lead to transient or definitive tracheotomy.

METHODS

We implemented a strict standard operative procedure beginning in January 2010 and modified our operative procedure. In all patients undergoing bilateral operation, we begin with the largest side or with the cancerous/suspicious side without dissecting the contralateral side. If the intraoperative neuromonitoring (IONM) signal is lost after stimulation of the vagus nerve at the end of the first side, we stop the procedure after the unilateral lobectomy, even if the recurrent nerve is anatomically intact and regardless of malignancy. If the IONM signal is lost, serial laryngoscopies are performed until recovery or definitive recurrent laryngeal nerve palsy is demonstrated. We report here our results in patients with loss of the IONM signal after lobectomy and discuss the medical implications for benign and malignant thyroid conditions.

RESULTS

Since January 2010, the operation has been stopped at the first side in 9 out of 220 planned bilateral thyroidectomies. There were five benign thyroid conditions and four thyroid cancers, including three papillary thyroid cancers and one bilateral medullary thyroid cancer in a patient with multiple endocrine neoplasia 2a. In two patients, it was a false-positive IONM loss. One of these two patients had the other lobe removed at day 3. In seven patients the laryngoscopy demonstrated total or partial laryngeal nerve palsy at day 1, but the recurrent nerve function recovered fully in all patients between 1 and 4 months postoperatively. All cancer patients were operated on the other side within 3 days to 3 months; one patient with a benign condition is being followed conservatively. One of the eight re-operated patients had transient recurrent nerve palsy postoperatively.

CONCLUSION

In our opinion, the systematic use of IONM and the change in operative strategy will lead to an almost 0% rate of bilateral laryngeal nerve palsy, at least in benign thyroid conditions. A loss of signal after the first side should prompt a halt in the procedure, even in cases of malignancies.

[Treatment of differentiated thyroid cancer]

The prevalence of thyroid cancer is steadily rising and the fortuitous discovery of a thyroid nodule is a frequent situation for the clinician. The clinical importance is the need to exclude thyroid cancer. In this article we present the initial work up and treatment options for differentiated thyroid cancer. Initial diagnosis is done with a dosage of thyroid stimulating hormone and a fine needle aspiration guided by ultrasonography, which permits classification of the lesion and guides the choice of treatment.

Defining teaching hospitals' GME strategy in response to new financial and market challenges

The authors present an overview of current graduate medical education (GME) issues, particularly the financial challenges to teaching hospitals resulting from the Balanced Budget and Tax Payer Relief Acts of 1997 and other recent market-driven factors. They describe in detail the nature of Medicare GME payments before and after the 1997 legislation, with specific examples, and explain the negative financial impact of the legislation and aspects of the legislation that are designed to alleviate that impact. Other factors influencing GME program size and composition are also discussed, including oversupplies or shortages of physicians, the concern that teaching hospitals are using public funds to train international medical graduates, changing training requirements, etc. The authors also describe a recent consulting assignment during which they assisted a major teaching hospital to develop a GME strategy that was responsive to the organization's mission and patients and that took into account future GME financing challenges. Detailed explanations are given of how the consultants analyzed the hospital's GME programs and finances, developed and ranked key institution-specific program criteria (strategic, organizational and operational, and financial), and, in consultation with all key stakeholders, formulated a GME strategy specific to the institution's needs. The authors conclude by cautioning that each institution's GME strategy will be different, but that it is important for institutions to develop such strategies to better face future challenges.