Pheochromocytoma Crisis

Pheochromocytomas are rare tumours of the adrenal gland that secrete catecholamines. The classical presentation of these tumours consists of a clinical triad of headaches, palpitations and diaphoresis. This clinical presentation should not be confused with the potentially fatal presentation of pheochromocytoma crisis, which may include severe haemodynamic instability and collapse, multi‐organ failure, hyperthermia and encephalopathy. When patients present in profound shock, supportive care and treatment are initiated. Patients presenting with pheochromocytoma crisis have an underlying adrenal tumour, but the clinical manifestations of this life‐threatening condition can mimic other entities. Once diagnosis is made, previous anecdotal evidence has shown that pheochromocytoma crisis is a surgical emergency. However, retrospective study of a larger sample of patients presenting with pheochromocytoma crisis suggests that medical management in the acute setting is appropriate and safe. The ultimate treatment is indeed surgical; however, there is no clear recommendation for the acute management of pheochromocytoma crisis. This chapter will focus on the medical and surgical management of potentially life‐threatening pheochromocytoma crisis. An in‐depth review of the clinical presentation, pathophysiology, causes and treatments of pheochromocytoma crisis will be provided, including the controversial areas surrounding decision‐making and timing for adrenalectomy

Primary Hyperparathyroidism Patients with Positive Preoperative Sestamibi Scan and Negative Ultrasound Are More Likely to Have Posteriorly Located Upper Gland Adenomas (PLUGs)

BackgroundStandard preoperative imaging for primary hyperparathyroidism usually includes sestamibi scanning (MIBI) and ultrasound (US). In a subset of patients with a positive MIBI and a negative US, we hypothesize that the parathyroid adenomas are more likely to be located posteriorly in the neck, where anatomically they are more difficult to detect by US.MethodsWe retrospectively reviewed the records of 661 patients treated for primary hyperparathyroidism between 2004 and 2009 at a tertiary referral center. We included patients who for their first operation had a MIBI that localized a single lesion in the neck and an US that found no parathyroid adenoma. We excluded patients with persistent or recurrent hyperparathyroidism, and patients with MIBIs that were negative, that had more than one positive focus, or that had foci outside of the neck. Sixty-six cases were included in the final analysis.ResultsA total of 54 patients (83%) had a single adenoma, 4 (6%) had double adenomas, and 7 (11%) had hyperplasia. Thirty-three patients (51%) had a single upper gland adenoma; 19 of these (58%) were posteriorly located upper gland adenomas (PLUGs). PLUGs occurred more often on the right side than on the left (P = 0.048, Fisher's test). PLUGs were also larger than other single adenomas (mean 1.85 vs. 1.48 cm, P = 0.021, t-test). Seventy-six percent of patients successfully underwent a unilateral or focused exploration. Six patients (9%) had persistent disease, which is double our group's overall average (4-5%).ConclusionsPrimary hyperparathyroid patients with preoperative positive MIBI and negative US are more likely to have PLUGs

Characteristics of contralateral carcinomas in patients with differentiated thyroid cancer larger than 1 cm

Purpose: Traditionally, total thyroidectomy has been advocated for patients with tumors larger than 1 cm. However, according to the ATA and NCCN guidelines (2015, USA), patients with tumors up to 4 cm are now eligible for lobectomy. A rationale for adhering to total thyroidectomy might be the presence of contralateral carcinomas. The purpose of this study was to describe the characteristics of contralateral carcinomas in patients with differentiated thyroid cancer (DTC) larger than 1 cm. Methods: A retrospective study was performed including patients from 17 centers in 5 countries. Adults diagnosed with DTC stage T1b-T3 N0-1a M0 who all underwent a total thyroidectomy were included. The primary endpoint was the presence of a contralateral carcinoma. Results: A total of 1

Characteristics of contralateral carcinomas in patients with differentiated thyroid cancer larger than 1 cm

textabstractPurpose: Traditionally, total thyroidectomy has been advocated for patients with tumors larger than 1 cm. However, according to the ATA and NCCN guidelines (2015, USA), patients with tumors up to 4 cm are now eligible for lobectomy. A rationale for adhering to total thyroidectomy might be the presence of contralateral carcinomas. The purpose of this study was to describe the characteristics of contralateral carcinomas in patients with differentiated thyroid cancer (DTC) larger than 1 cm. Methods: A retrospective study was performed including patients from 17 centers in 5 countries. Adults diagnosed with DTC stage T1b-T3 N0-1a M0 who all underwent a total thyroidectomy were included. The primary endpoint was the presence of a contralateral carcinoma. Results: A total of 1313 patients were included, of whom 426 (32 %) had a contralateral carcinoma. The contralateral carcinomas consisted of 288 (67 %) papillary thyroid carcinomas (PTC), 124 (30 %) follicular variant of a papillary thyroid carcinoma (FvPTC), 5 (1 %) follicular thyroid carcinomas (FTC), and 3 (1 %) Hürthle cell carcinomas (HTC). Ipsilateral multifocality was strongly associated with the presence of contralateral carcinomas (OR 2.62). Of all contralateral carcinomas, 82 % were ≤10 mm and of those 99 % were PTC or FvPTC. Even if the primary tumor was a FTC or HTC, the contralateral carcinoma was (Fv)PTC in 92 % of cases. Conclusions: This international multicenter study performed on patients with DTC larger than 1 cm shows that contralateral carcinomas occur in one third of patients and, independently of primary tumor subtype, predominantly consist of microPTC

Microsatellite instability in thyroid neoplasia

Micro satellite instability (MSI) is a form of genomic instability that has recently been implicated in the pathogenesis of thyroid cancer. The purpose of this study is to further define the distribution of microsatellite instability in both normal and neoplastic thyroid follicular epithelium.Using laser capture microdissection, cells from both normal and tumor tissue were individually collected. PCR amplification of the DNA was then performed using six dinucleotide and two mononucleotide microsatellite markers.Forty benign and malignant thyroid tumors were compared with their adjacent normal thyroid follicular tissue and were analyzed for MSI. 9/14 papillary thyroid carcinomas and 10/16 of follicular thyroid carcinomas demonstrated MSI at >30--40% of loci tested. For benign follicular adenomas, 9/10 demonstrated microsatellite stability or low-frequency MSI.Microsatellite instability appears to play a role in thyroid pathogenesis as evidenced by the high frequency of MSI in malignant thyroid neoplasms. In addition our study showed a significant difference in MSI frequency between follicular adenomas and follicular carcinomas. More importantly, the technique of laser capture microdissection allows for more accurate selection of benign, malignant and normal DNA

The Evolution of Biomarkers in Thyroid Cancer—From Mass Screening to a Personalized Biosignature

cancer

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

Incidental thyroid uptake on PET scanning: epidemiology, clinical significance, and management challenge

Incidental lesions of the thyroid are increasingly discovered as the prevalence of medical imaging escalates. The likelihood of malignancy must be assessed for each of these incidentalomas. The utility of the metabolic data derived from the identification of these lesions on PET/CT imaging is unclear. The overall rate of detection of thyroid incidentalomas on PET/CT is estimated at 1.5%-4.2%. However, this rate varies by the pattern of uptake. Several studies have evaluated predictive measures such as maximal standardized uptake value (SUVmax) and radiomics. However, no definitive conclusion has been reached. Given that the majority of PET/CT scans are performed in the context of malignancy, we recommend first assessing the general condition and life expectancy of patients when PET-detected thyroid incidentalomas are unveiled. We also recommend considering observation versus diagnostic workup with further imaging and/or fine-needle aspiration and cytology