Presentation and management of pheochromocytomas and paragangliomas: about 40 cases

Background Pheochromocytoma and paraganglioma are rare neuroendocrine tumors of the chromaffin tissue, which may produce catecholamines. The aim of our study was to analyze the clinical and para-clinical aspects as well as the therapeutic and evolutionary aspects of pheocromocytomas and paragangliomas based on a series of 40 cases. Methods Our retrospective population-based research study includes 40 patients. Then, a statistical analysis was carried out using the SPSS software (version21). Results Our study involves 40 patients, including 23 women (57, 5%) and 17 men (42,5%). The mean age at the time of the diagnosis was 43.8 ± 16.8 years. The circumstances of the discovery were mainly characterized by adrenal incidentaloma and hypertension. The biological diagnosis was based on the dosage of urinary metanephrines and plasma-free metanephrines in, respectively, 61.5% and 18% of cases. A computerized tomography scan and/or a magnetic resonance imaging scan could help to locate the tumor in 100% of cases. Our series includes 3 cases of bilateral pheochromocytoma, 3 cases of paragangliomas and 1 case of malignant pheochromocytoma, while a hereditary form was retained in 3 patients. In fact, thirty-two patients were operated; cure was clinically labeled in 100% and biologically in 87.5% of patients. Conclusions The main points for improvement that our study has revealed are; a patient follow-up after surgery, which was not always regular, and an insufficient screening for genetic diseases associated with pheochromocytomas and paragangliomas.

Pheochromocytoma Rupture Associated With Systemic Anticoagulation: A Case Report

Background: Pheochromocytoma rupture is a rare endocrine emergency. There have been approximately 85 documented cases, and the mortality rate for patients who require emergent surgery is as high as 34% (1). Clinical Case: A 30-year-old man with no past medical history presented to the Emergency Department with abdominal pain and vomiting. He was hypertensive, tachycardic, and hypoxic. CT Chest Angiogram revealed bilateral pulmonary emboli and a 6.5 x 5.5 x 6.4 cm left heterogenous adrenal mass. His plasma free metanephrines were elevated to 31,173 pg/mL (n<62 pg/mL) with normetanephrines >50,000 pg/mL (n<145 pg/mL). His pulmonary emboli was treated with continuous intravenous heparin, and he was also treated with intravenous fluids and phentolamine due to concern for pheochromocytoma. Within hours, he became hypotensive, and his hemoglobin downtrended from 16.4 g/L to 7.3 g/L (n 14–18 g/L). Repeat CT showed that the adrenal mass had ruptured, enlarging to 15.4 x 9.7 x 10.0 cm. He was taken for an emergent laparotomy with piecemeal resection of the mass; surgical pathology confirmed a pheochromocytoma. Fortunately, the patient recovered well after surgery. After 6 months, his plasma free metanephrines normalized to 15 pg/mL with normetanephrines of 80 pg/mL. His DOTATATE scan was negative for malignancy and his genetic testing was negative. Conclusion: The patient’s systemic anticoagulation and critical illness likely increased his risk for pheochromocytoma rupture. Standard preoperative pheochromocytoma management, to include aggressive fluid resuscitation and alpha blockade, is important in reducing risk of morbidity and mortality. Biochemical follow up is required, as there is a 16% risk of recurrence. Reference: (1) Kobayashi T, Iwai A, Takahashi R, Ide Y, Nishizawa K, Mitsumori K. Spontaneous rupture of adrenal pheochromocytoma: Review and analysis of prognostic factors. Journal of Surgical Oncology. 2005;90(1).

Gastrointestinal Stromal Tumor Mimicking an Adrenal Incidentaloma: A Case Report

Background: The differential diagnosis of adrenal incidentalomas is broad and includes benign or malignant primary adrenal lesions, metastases, myelolipomas, infections or hemorrhage. We present here a patient with a gastrointestinal stromal tumor (GIST) presenting as an adrenal incidentaloma. Clinical Case: A 64-year-old man was referred to Endocrinology for the work-up of a left adrenal incidentaloma discovered on an abdominal CT scan performed for left upper quadrant abdominal pain. His past medical history included well-controlled type 2 diabetes and hypertension. On subsequent imaging, the mass was described as a solid homogenous nodule with a density of 31 HU and an absolute contrast washout of 22%. Between 2017 and 2020, the mass’ size increased from 14 x 13 to 24 x 19 millimeters. Further functional imaging revealed no 131I-MIBG uptake but moderate hypermetabolism on FDG PET-CT with a SUVmax of 4.5. There was discordance regarding the mass’ localization between the various imaging modalities used preoperatively: some showed a left adrenal lesion whereas others suggested that it was adjacent to, but distinct from, the adrenal gland. Biochemical workup included normal 1-mg dexamethasone suppression test, serum potassium levels, 24-hour urine fractionated catecholamines, as well as plasma free metanephrines and normetanephrines. Chromogranin A levels were also normal. In light of these findings, laparoscopic tumor resection, with or without left adrenalectomy, was scheduled. During surgery, it was discovered that the tumor was intraperitoneal, located next to the splenic hilum and originating from the greater curvature of the stomach; a partial gastrectomy was therefore performed, without left adrenalectomy. Pathological evaluation revealed that the mass was a small spindle cell-type GIST. Genetic analysis of the tumoral DNA showed a somatic mutation in exon 11 of the KIT gene (c.1658_1669del, p.Tyr553_Gln556del). Conclusion: We report a rare case of gastric GIST initially mimicking a left adrenal incidentaloma. Localization of GISTs in the adrenal area is rare, with very few cases reported to date in the literature. Unlike other cases described previously, our patient underwent the right procedure thanks to adequate tumor localization during surgery. However, as some patients have experienced unnecessary adrenalectomy for similar clinical presentations, gastric GISTs should be kept in mind in the differential diagnosis of non-functional atypical adrenal masses, especially in the presence of suspicious PET scan imaging. References: 1. Hexi Du, Jun Zhou, Cheng Yang, Li Zhang, Chaozhao Liang: Gastrointestinal stromal tumor masquerading as an adrenal tumor: a case report with literature review. Int J Clin Exp Med 2017;10(10):14883-14887.

Quantitative Measurement of Plasma Free Metanephrines by a Simple and Cost-Effective Microextraction Packed Sorbent with Porous Graphitic Carbon and Liquid Chromatography-Tandem Mass Spectrometry

Plasma free metanephrines are widely used for the diagnosis of pheochromocytoma and paraganglioma (PPGL), yet quantifying metanephrines using a simple and cost-effective approach may be challenging due to preanalytical and analytical constraints. In this study, we established and validated a new method for quantitative measurement of plasma free metanephrines based on microextraction by packed sorbent (MEPS) with porous graphitic carbon (PGC) and liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). The elution step was fully compatible with HILIC mode without evaporation and reconstitution. The analytes were well resolved, and potential interferences (54 substances) were investigated. This method was linear from 24.7–2717 pg/mL for metanephrine (MN) and 24.5–4010 pg/mL for normetanephrine (NMN) with a coefficient of determination (R2) higher than 0.994. The limit of MN and NMN detection were 12.4 pg/mL and 12.3 pg/mL, respectively. The intra- and interassay impressions were ≤12.8% for spiked quality controls and ≤13.6% for commercial quality controls; the method recoveries ranged within 88.0–109.0%, respectively. The area under the receiver operating characteristic (ROC) curve was 0.848 ± 0.047 for MN and 0.979 ± 0.021 for NMN. Validation that was performed by comparing clinical specimens with various biochemical results showed that plasma free metanephrines in a seated position had comparable sensitivity and lower specificity to urinary free metanephrines, which could be compensated by combining other biochemical tests. The newly developed MEPS method resulted as a time-saving, reliable, and cost-effective microextraction technique that can be applied for a successful screening of PPGL.

Plasma metanephrines and prospective prediction of tumor location, size and mutation type in patients with pheochromocytoma and paraganglioma

ObjectivesPlasma free metanephrines are commonly used for diagnosis of pheochromocytoma and paraganglioma (PPGLs), but can also provide other information. This multicenter study prospectively examined whether tumor size, location, and mutations could be predicted by these metabolites.MethodsPredictions of tumor location, size, and mutation type, based on measurements of plasma normetanephrine, metanephrine, and methoxytyramine were made without knowledge of disease in 267 patients subsequently determined to have PPGLs.ResultsPredictions of adrenal vs. extra-adrenal locations according to increased plasma concentrations of metanephrine and methoxytyramine were correct in 93 and 97% of the respective 136 and 33 patients in who these predictions were possible. Predicted mean tumor diameters correlated positively (p<0.0001) with measured diameters; predictions agreed well for pheochromocytomas but were overestimated for paragangliomas. Considering only patients with mutations, 51 of the 54 (94%) patients with NF1 or RET mutations were correctly predicted with those mutations according to increased plasma metanephrine, whereas no or minimal increase in metanephrine correctly predicted all 71 patients with either VHL or SDHx mutations; furthermore, among the latter group increases in methoxytyramine correctly predicted SDHx mutations in 93% of the 29 cases for this specific prediction.ConclusionsExtents and patterns of increased plasma O-methylated catecholamine metabolites among patients with PPGLs allow predictions of tumor size, adrenal vs. extra-adrenal locations and general types of mutations. Predictions of tumor location are, however, only possible for patients with clearly increased plasma methoxytyramine or metanephrine. Where possible or clinically relevant the predictions are potentially useful for subsequent clinical decision-making.

Measurements of Plasma-Free Metanephrines by Immunoassay Versus Urinary Metanephrines and Catecholamines by Liquid Chromatography with Amperometric Detection for the Diagnosis of Pheochromocytoma/Paraganglioma

Studies conflict concerning the use of enzyme immunoassays (EIA) for plasma free metanephrines (P-MNs) vs. other methods for pheochromocytoma/paraganglioma (PPGL) diagnosis. We compared commercially available EIAs for P-MNs with high-pressure liquid chromatography (HPLC) for 24 h-urinary MNs (U-MNs) and -catecholamines (U-CATs). 943 (565 female, 378 male) patients (54 PPGL, 889 Non-PPGL) were studied. Simultaneous measurements of all parameters analyzed at the central lab of our university hospital was mandatory for inclusion. Sensitivity of P-MNs (94.4%) was similar to that of U-MNs (100%), and both were higher than of U-CATs (77.8%), specificity of P-MNs (100%) higher than of U-MNs (73.6%), and similar to U-CATs (99.8%). With the recently proposed downward adjusted ULN of P-MNs to correct for the reported negative bias of the EIAs sensitivity (98.1%) raised non-significantly, but specificity decreased significantly (94.8%). Areas under receiver-operating characteristic curves indicated comparable diagnostic performance of P-MNs (0.989) vs. U-MNs (0.995), both better than U-CATs (0.956). In summary, the EIAs to measure P-MNs performed similarly to U-MNs by HPLC, and both better than U-CATs by HPLC. The post-test probability of PPGL given a positive test result was best for P-MNs, and higher than for the other pairs of analytes. Downward corrections of ULN of P-MNs did not improve test performances.

A SERIES OF TWO PATIENTS WITH CARDIAC PARAGANGLIOMAS

Objective: The objective of this report is to present 2 cases of cardiac paragangliomas (PGLs), and to outline the presentation, management, and associated genetic mutations. Methods: Case 1, a 38-year-old female, presented with a 12-month history of paroxysmal palpitations, headaches, and weight loss. Her investigations included plasma free metanephrines and urinary metanephrines, 68-gallium DOTATATE positron emission tomography/computed tomography, and cardiac imaging. Case 2, a 28-year-old male, presented with a hypertensive crisis and abdominal pain on a background of hypertension. Given his abdominal pain, he was investigated with an abdominal computed tomography (CT) scan, followed by plasma free meta-nephrines and urinary metanephrines, echocardiogram, and 123-iodine meta-iodobenzylguanidine single-photon emission CT. Results: Case 1 had an elevated plasma normetadrenaline of 6,750 pmol/L (reference range is <900 pmol/L) and 3-methoxytyramine of 1,845 pmol/L (reference range is <110 pmol/L). 68-gallium DOTATATE positron emission tomography/computed tomography showed an avid cardiac lesion. The lesion was resected, and histopathology confirmed PGL. Genetic studies revealed an SDHC gene mutation. For case 2, abdominal CT revealed a para-spinal mass. Workup for this lesion revealed elevated normetadrenaline of 56,000 pmol/L (reference range is <900 pmol/L). An echocardiogram, arranged for investigation of hypertension, showed an additional cardiac mass. A 123-iodine meta-iodobenzylguanidine single-photon emission CT scan confirmed that both masses were functioning. The lesions were successfully excised. He was found to have an SDHB gene mutation. Conclusion: Both patients had long-standing symptoms secondary to catecholamine excess, thus it is important to promptly screen patients with unexplained hypertension or paroxysmal symptoms of palpitations, headaches, and diaphoresis with plasma free metanephrines or urinary metanephrines. All patients with PGLs should be offered genetic testing due to the high incidence of genetic mutations.

Case report of a phantom pheochromocytoma

Plasma free metanephrines or urinary fractionated metanephrines are the biochemical tests of choice for the diagnosis of pheochromocytoma as they have greater sensitivity and specificity than catecholamines for pheochromocytoma detection. This case highlights the preanalytical factors which can influence metanephrine measurement and cause a false positive result. It describes a patient with a high pre-test probability of pheochromocytoma due to hypertension and a past medical history of adrenalectomy for a purported pheochromocytoma in her home country. When biochemical screening revealed grossly elevated urine normetanephrine in the presence of a previously identified right adrenal lesion, there was high clinical suspicion of a pheochromocytoma. However, functional imaging did not support this view which prompted additional testing with plasma metanephrines. Results for plasma and urine metanephrines were discordant and preanalytical drug interference was suspected. Patient medications were reviewed and sulfasalazine, an anti-inflammatory drug was identified as the most likely analytical interferent. Urinary fractionated metanephrines were re-analysed using liquid chromatography tandem mass spectrometry (LC-MS/MS) and all metanephrines were within their reference intervals. This case illustrates how method-specific analytical drug interference prompted unnecessary expensive imaging, heightened patient anxiety and resulted in lengthy investigations for what turned out to be a phantom pheochromocytoma.