Non-functional urinary bladder paraganglioma with negative Ga-DOTA-NOC PET/CT uptake

Background Paraganglioma of the urinary bladder is a very rare benign tumor that constitutes less than 0.5% of all bladder tumors. It can be functional and non-functional. Functional tumors present with symptoms of catecholamine excess, and non-functional tumors usually remain asymptomatic. Case presentation Here, we present a case of non-functional urinary bladder paraganglioma in a 36-year-old female who presented to us with a history of intermittent hematuria. The routine hematological and biochemical parameters were within normal limits. Diagnostic computed tomography (CT) revealed a hypervascular lesion in the urinary bladder dome with no significant uptake in gallium-68-labelled-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid peptides-NaI3-octreotide positron emission tomography (DOTA-NOC PET/CT). Histopathology and immunohistochemistry confirmed the diagnosis of paraganglioma. Conclusion We present this case because of the rare location of paraganglioma in the urinary bladder and being non-functional with low/absent somatostatin receptor expression.

Dopamine secreting pheochromocytoma and paraganglioma

Predominantly or exclusively dopamine-secreting pheochromocytoma and paraganglioma are very rare. We report a 64-year-old woman with an adrenal incidentaloma. She was normotensive and had no symptoms of catecholamine excess. The 24-hour urine catecholamine level showed normal norepinephrine (122.9 μg/day), epinephrine (24.3 μg/day), whereas markedly elevated dopamine (148,212.4 μg/day). 123I-metaiodobenzylguanidine (MIBG) scintigraphy revealed tumor uptake. After α-blockade as preoperative management, she successfully underwent laparoscopic left adrenalectomy and was finally diagnosed with an exclusively dopamine-secreting pheochromocytoma. The tumor was histologically comprised of small polygonal cells with high cellularity and was immunohistochemically positive for all three catecholamine synthesizing enzymes: tyrosine hydroxylase (very weak), dopamine β-hydroxylase (heterogeneous), and phenylethanolamine N-methyltransferase (very weak). Electron microscopy revealed very few catecholamine-containing small vesicles with a few organelles, which reflected immature cells. No biochemical or imaging evidence of recurrence or metastasis were evident 1 year after the surgery. We conducted a literature search in the Pubmed database. A total of 33 cases were collected. Our case had the second-highest 24-hour urinary dopamine excretion and was the first in which immunostaining for catecholamine synthase and electron microscopy were performed together. Histological findings in our case give a possible hypothesis that the mechanism underlying a dopamine-secreting pheochromocytoma is associated with immature catecholamine vesicles in which DBH is localized, thus resulting in inhibited conversion from dopamine to norepinephrine. We also discuss the reasons for the lack of catecholamine excess symptoms, whether preoperative management of α-blockade is needed, and the association between the prognosis and genetic mutation with an extensive literature review.

Pre- versus post-operative untargeted plasma nuclear magnetic resonance spectroscopy metabolomics of pheochromocytoma and paraganglioma

Purpose Pheochromocytomas and Paragangliomas (PPGL) result in chronic catecholamine excess and serious health complications. A recent study obtained a metabolic signature in plasma from PPGL patients; however, its targeted nature may have generated an incomplete picture and a broader approach could provide additional insights. We aimed to characterize the plasma metabolome of PPGL patients before and after surgery, using an untargeted approach, and to broaden the scope of the investigated metabolic impact of these tumors. Design A cohort of 36 PPGL patients was investigated. Blood plasma samples were collected before and after surgical tumor removal, in association with clinical and tumor characteristics. Methods Plasma samples were analyzed using untargeted nuclear magnetic resonance (NMR) spectroscopy metabolomics. The data were evaluated using a combination of uni- and multi-variate statistical methods. Results Before surgery, patients with a nonadrenergic tumor could be distinguished from those with an adrenergic tumor based on their metabolic profiles. Tyrosine levels were significantly higher in patients with high compared to those with low BMI. Comparing subgroups of pre-operative samples with their post-operative counterparts, we found a metabolic signature that included ketone bodies, glucose, organic acids, methanol, dimethyl sulfone and amino acids. Three signals with unclear identities were found to be affected. Conclusions Our study suggests that the pathways of glucose and ketone body homeostasis are affected in PPGL patients. BMI-related metabolite levels were also found to be altered, potentially linking muscle atrophy to PPGL. At baseline, patient metabolomes could be discriminated based on their catecholamine phenotype.

Plasma Metabolome Profiling for the Diagnosis of Catecholamine Producing Tumors

ContextPheochromocytomas and paragangliomas (PPGL) cause catecholamine excess leading to a characteristic clinical phenotype. Intra-individual changes at metabolome level have been described after surgical PPGL removal. The value of metabolomics for the diagnosis of PPGL has not been studied yet.ObjectiveEvaluation of quantitative metabolomics as a diagnostic tool for PPGL.DesignTargeted metabolomics by liquid chromatography-tandem mass spectrometry of plasma specimens and statistical modeling using ML-based feature selection approaches in a clinically well characterized cohort study.PatientsProspectively enrolled patients (n=36, 17 female) from the Prospective Monoamine-producing Tumor Study (PMT) with hormonally active PPGL and 36 matched controls in whom PPGL was rigorously excluded.ResultsAmong 188 measured metabolites, only without considering false discovery rate, 4 exhibited statistically significant differences between patients with PPGL and controls (histidine p=0.004, threonine p=0.008, lyso PC a C28:0 p=0.044, sum of hexoses p=0.018). Weak, but significant correlations for histidine, threonine and lyso PC a C28:0 with total urine catecholamine levels were identified. Only the sum of hexoses (reflecting glucose) showed significant correlations with plasma metanephrines.By using ML-based feature selection approaches, we identified diagnostic signatures which all exhibited low accuracy and sensitivity. The best predictive value (sensitivity 87.5%, accuracy 67.3%) was obtained by using Gradient Boosting Machine Modelling.ConclusionsThe diabetogenic effect of catecholamine excess dominates the plasma metabolome in PPGL patients. While curative surgery for PPGL led to normalization of catecholamine-induced alterations of metabolomics in individual patients, plasma metabolomics are not useful for diagnostic purposes, most likely due to inter-individual variability.

Pre- Versus Post-Operative Untargeted Plasma Nuclear Magnetic Resonance Spectroscopy Metabolomics of Pheochromocytoma And Paraganglioma

Purpose: Pheochromocytomas and Paragangliomas (PPGL) result in chronic catecholamine excess and serious health complications. A recent study obtained a metabolic signature in plasma from PPGL patients; however, its targeted nature may have generated an incomplete picture and a broader approach could provide additional insights. We aimed to characterize the plasma metabolome of PPGL patients before and after surgery, using an untargeted approach, and to broaden the scope of the investigated metabolic impact of these tumors.Design: A cohort of 36 PPGL patients was investigated. Blood plasma samples were collected before and after surgical tumor removal, in association with clinical and tumor characteristics.Methods: Plasma samples were analyzed using untargeted nuclear magnetic resonance (NMR) spectroscopy metabolomics. The data were evaluated using a combination of uni- and multi-variate statistical methods.Results: Before surgery, patients with a nonadrenergic tumor could be distinguished from those with an adrenergic tumor based on their metabolic profiles. Tyrosine levels were significantly higher in patients with high compared to those with low BMI. Comparing subgroups of pre-operative samples with their post-operative counterparts, we found a metabolic signature that included ketone bodies, glucose, organic acids, methanol, dimethyl sulfone and amino acids. Three signals with unclear identities were found to be affected.Conclusions: Our study demonstrates how the pathways of glucose and ketone body homeostasis are affected in PPGL patients. BMI-related metabolite levels were also found to be altered, potentially linking muscle atrophy to PPGL. At baseline, patient metabolomes could be discriminated based on their catecholamine phenotype.

Concomitant Pheochromocytoma and Primary Aldosteronism: A Case Series and Literature Review

Context The detection and management of concomitant pheochromocytoma (PHEO) and primary aldosteronism (PA) is not well understood. Objective To investigate varying presentations and outcomes of cases with coexisting PHEO and PA to provide an approach to its diagnosis and management. Design Retrospective case series from 2000-2020; additional review of cases before 2000 and from the medical literature. Setting Single institution tertiary center. Patients Adults with concomitant PHEO and PA. Main Outcome Measures Clinical, biochemical, radiologic, and histologic parameters. Results Fifteen patients (53% men, median age 53 years) were diagnosed with concomitant PHEO and PA. The majority presented with hypertension (13, 87%) and hypokalemia (13, 87%), and 6 (40%) presented with symptoms suggestive of catecholamine excess. All patients who underwent preoperative work-up for catecholamine excess (14, 93%) were found to have biochemical levels above the upper limits of normal. Adrenal vein sampling (AVS) was performed in 9 patients (60%), where 5 (56%) were diagnosed with bilateral PA, and 4 (44%) with unilateral PA. Patients underwent either unilateral (12, 80%) or bilateral (3, 20%) adrenalectomy. Biochemical improvement or resolution of catecholamine excess was confirmed in all cases with documented measurements. Recurrence of PHEO was not observed. Six patients (40%) displayed persistent PA postoperatively. Conclusions Concomitant PHEO and PA is a rare but likely under-reported condition. Hypertension with or without hypokalemia should prompt evaluation for PA, while any indeterminate adrenal mass should be assessed for PHEO. Coexisting disease warrants consideration of AVS to determine the laterality of PA to ensure appropriate management.

Interpreting Normetanephrines-the Significance of Clinical Context

Introduction: Pheochromocytoma ranges in presentation, but the diagnostic hallmarks are increased catecholamine secretion in patients with an adrenal mass. However, interpretation requires consideration of the clinical state. Case: A 60-year-old man presented with 6 months of episodic flushing, night sweats, fatigue, back pain, and 20-pound weight loss. Vitals were notable for hypotension and mild tachycardia. He was thin with evidence of hyperpigmentation. Contrasted CT showed 15 cm heterogeneous masses of both adrenals and a rib lesion. Plasma normetanephrines were elevated on two separate measures (526 and 1,398 pg/mL, nl <=148). Plasma metanephrines were normal. Urine normetanephrines were increased 4-fold (2,165mcg/g Cr, n 108–524). Labs noted low DHEA-S (2 mcg/dL, n 38–313), high ACTH (204 pg/mL, n 6–50), random cortisol (5.2 mcg/dL, n 3.5–18.3), undetectable aldosterone, and high plasma renin activity (83 ng/mL/h, n 2.9–10.8). Cortisol peaked at 6.7 mcg/dL 1 hour after 250mcg of cosyntropin. MRI revealed over 15cm infiltrating masses arising from adrenals with modest flare on T2 imaging. Dotatate PET/CT showed mild uptake of bilateral adrenals and metastases to liver and bone. He was started on steroid replacement and doxazosin for presumed pheochromocytoma. He was transferred to our facility where he remained hypotensive despite adequate glucocorticoid and mineralocorticoid replacement. Once stabilized, repeat plasma normetanephrines were insignificant (218 pg/mL, n 0–145) and chromogranin was normal (68 ng/mL, n<93). Biopsy of the rib lesion confirmed diffuse large B-cell lymphoma. Discussion: Pheochromocytoma classically presents in the outpatient setting with palpitations, diaphoresis, pallor, and paroxysmal hypertension. Rarely, it results in hypertensive emergencies requiring hospitalization. In patients with catecholamine excess and an adrenal mass, pheochromocytoma is usually suspected. 3-fold or more increases of normetanephrines or metanephrines above upper cutoffs are rarely false-positives. However, this assumes clinical stability. Sympathoadrenal activation is a physiologic response to acute illness. Metanephrines in critically ill patients without pheochromocytoma approached those of pheochromocytoma in one study. Levels normalized upon recovery from illness, highlighting the importance of verifying biochemistries once the patient is stable. The degree of elevation in normetanephrines seen in this patient was a physiologic response to adrenal insufficiency and clinical instability. Pathology confirmed lymphoma rather than pheochromocytoma for which he was started on chemotherapy. Conclusion: Elevated normetanephrines is an appropriate physiological response in the acutely ill. Careful consideration of the clinical picture in conjunction with biochemical data is critical.

Concomitant Pheochromocytoma and Primary Aldosteronism: A Case Series and Literature Review

Objective: The detection and management of concomitant pheochromocytoma (PHEO) and primary aldosteronism (PA) is not well understood. Our objectives were to investigate varying presentations and outcomes of cases with coexisting PHEO and PA to provide an approach to its diagnosis and management. Design: Retrospective case series from 2000–2020 at a single institution tertiary center; additional review of previously known cases before 2000 and from the medical literature. Patients and Measurements: Adult patients with concomitant PHEO and PA. Clinical, biochemical, radiologic, and histologic parameters were reviewed. Results: Fifteen patients (53% men, median age 53 years) were diagnosed with concomitant PHEO and PA. The majority presented with hypertension (13, 87%) and hypokalemia (13, 87%), but only 6 (40%) presented with symptoms suggestive of catecholamine excess. All patients with preoperative work-up for catecholamine excess (14, 93%) were found to have elevated plasma or urinary metanephrines/catecholamines above the upper limit of normal. Adrenal vein sampling (AVS) was performed in 9 (60%) patients, where 5 (56%) were diagnosed with bilateral PA, and 4 (44%) with unilateral PA. All patients underwent either unilateral (12, 80%) or bilateral (3, 20%) adrenalectomy to treat their PHEO and/or PA. Postoperative catecholamines and/or catecholamine breakdown products normalized or improved in 13 (87%) patients and were not measured in 2. Recurrence of PHEO was not observed. Six (40%) displayed persistent PA postoperatively, where 4 required long-term mineralocorticoid blockade. Conclusions: Concomitant PHEO and PA is a rare but likely under-reported condition. Hypertension with or without hypokalemia should prompt evaluation for PA, while any indeterminate adrenal mass should be worked up for PHEO. Coexisting disease warrants consideration of AVS to determine the laterality of PA to ensure appropriate management.

A Unique Presentation of a Paraganglioma and Its Consequences

Introduction: Paragangliomas (PGL) are extremely rare tumors arising from extra-adrenal neural crest cells with an incidence of 0.8 per 100,000 person-years. Sympathetic chain PGLs usually arise in the abdomen, with about 75% of them arising intra-abdominally [2]. On CT or MRI, PGLs are usually have homogenous enhancement or central areas of low attenuation. The consequences of PGLs are many, and one complication that is rarely noted is glycemic disturbances with catecholamine excess. Here, we present a case of a radiographically unique appearing PGL that resulted in dramatic improvement of diabetes after resection. Case: 41 year old male with a past medical history of diabetes, CKD and developmental delay presented with hyperglycemia. Patient’s home regimen of Glargine 15 units qHS and Humalog 5 units TID AC had run out a few days prior. Patient had Hemoglobin A1c of 11.8% mg/dL and a C-peptide of 0.4 ng/ml. Endocrine was initially consulted for glucose management. Hospital course was complicated by abdominal pain and CT imaging showed low attenuation splenic masses, retroperitoneal lymphadenopathy and a large, necrotic appearing mesenteric mass consistent with lymphoma. MRI reaffirmed mass with peripheral enhancement and central necrosis consistent with neoplasm. Patient underwent biopsy of lymphadenopathy, which came back benign and then went for biopsy of mass. As the needle entered the mass, the patient became acutely hypertensive and tachycardic. He received phentolamine with good response and labs were drawn for catecholamine producing tumor. Plasma norepinephrine level was 6048 pg/ml and a chromogranin level of 4788 ng/ml. An MIBG scan revealed focal uptake at the lesion without evidence of metastasis. In the subsequent weeks, he was alpha- and then beta-blocked and underwent resection of mass that was complicated by transient hypotension and hypoglycemia. Eventually, patient’s blood pressure was controlled and insulin requirements dropped precipitously to just requiring 4 units of glargine by discharge. Discussion: This patient had a mass on CT scan that appeared to be consistent with lymphoma as opposed to PGL that led to biopsy and subsequent catecholamine crisis. Fortunately, this was controlled and subsequent resection led to improvement in the patient’s glycemic control. It has been thought that glucose intolerance in PGL patients is due to impaired insulin release through desensitization of the beta-adrenergic receptor. Furthermore, Catecholamines, as counter-regulatory hormones, have been well documented to raise blood sugar on this basis as well. Fortunately for our patient, he survived an initial biopsy and post-operatively, was able to actually have an improvement in his glycemic control. It also is a reminder to always do a screen for PGL before doing a needle biopsy of a compatible abdominal mass.