Pheochromocytomas Most Commonly Present As Adrenal Incidentalomas: A Large Tertiary Center Experience

CONTEXT

Pheochromocytomas are increasingly diagnosed in incidentally detected adrenal masses. However, the characteristics of incidental pheochromocytomas are unclear.

OBJECTIVE

We aimed to assess the proportion and clinical, biochemical, radiological, genetic, histopathological, and follow-up characteristics of incidental pheochromocytomas.

METHODS

A retrospective review was conducted of patients with pheochromocytoma seen between January 2010 and October 2022 at a large UK tertiary care center. The diagnosis was confirmed histologically or by the combined presence of increased plasma and/or urinary metanephrines (MN), indeterminate adrenal mass on cross-sectional imaging, and metaiodobenzylguanidine avidity.

RESULTS

We identified 167 patients with pheochromocytoma; 144 (86.2%) underwent adrenalectomy, for 23 (13.8%) surgery was either awaited, deemed unsuitable due to frailty or other metastatic malignancy, or declined by the patients. Excluding pheochromocytomas diagnosed via screening genetically predisposed individuals (N = 20), 37 of 132 (28.0%) presented with adrenergic symptoms and/or uncontrolled hypertension, while 91 of 132 (69.0%) patients presented with an incidentally detected adrenal mass. Incidentally detected patients were older (median age 62 years) than those detected due to clinical suspicion (aged 42 years) or after genetic screening (aged 33 years) (all P < .05). Incidentally detected pheochromocytomas were smaller (median 42 mm) than tumors detected due to adrenergic symptoms/uncontrolled hypertension (60 mm), but larger than tumors identified by genetic screening (30 mm) (all P < .05). Increased MN excretion showed a similar pattern (symptomatic/uncontrolled hypertension > incidental > genetic screening) (all P < .05). Hereditary predisposition was detected in 20.4% of patients (incidental, 15.3%; symptomatic/uncontrolled hypertension, 42.9%).

CONCLUSION

The majority of pheochromocytomas are diagnosed incidentally and have distinct clinical, radiological, biochemical, and genetic features. Their detection at older age but smaller size may point to a different underlying tumor biology.

Massive Biochemically Silent Pheochromocytoma Masquerading as Nonfunctioning Adrenocortical Cancer

Pheochromocytomas are rare catecholamine-secreting neuroendocrine tumors of the adrenal medulla chromaffin cells, usually associated with features of catecholamine excess. Clinically and biochemically silent pheochromocytoma without adrenergic symptoms or elevated catecholamine concentrations are rare. A 71-year-old female presented with acute right flank pain with abdominal computed tomography (CT) scan revealing a hemorrhagic right adrenal mass. She had no preceding adrenergic symptoms, and normal serum electrolytes, on a background of well-controlled hypertension on amlodipine monotherapy. After conservative management and discharge, an outpatient CT adrenal scan confirmed an 88 × 64 mm right adrenal mass demonstrating intense avidity (maximum standardized uptake value, 20.2) on fluorodeoxyglucose F 18-positron emission tomography (FDG-PET)/CT scan. Biochemical screening supported a nonfunctional adrenal lesion with normal-range plasma normetanephrines and metanephrines. She underwent a right adrenalectomy for presumed nonfunctioning adrenocortical cancer; however, histopathology demonstrated a 120-mm pheochromocytoma. Succinate dehydrogenase subunit B (SDHB) and fumarate hydratase (FH) staining were retained; however, weakly positive 2SC staining raised concerns for FH-deficient pheochromocytoma. Germline DNA sequencing was negative for pathogenic RET, VHL, SDHB, SDHD, or FH variants. Tumor cells stained positive for tyrosine hydroxylase and negative for dopamine β hydroxylase. Four months postoperatively, progress FDG-PET/CT scan demonstrated no focal avidity. Massive biochemically silent pheochromocytomas are exceedingly rare, and we discuss various mechanisms that may predispose patients to this phenomenon.

Secondary hypertension: An update on the diagnosis and localisation of a pheochromocytoma or paraganglioma

Most cases of hypertension are because of essential hypertension, however 5% – 15% of cases can be a result of a secondary cause. In this article, we focus on the endocrine causes of secondary hypertension with a particular focus on pheochromocytomas (PCCs) and paragangliomas (PGLs). Around 15 endocrine disorders can initially present with hypertension. Amongst those PCCs and PGLs are rare but potentially life-threatening causes. An early diagnosis and timely referral can be life-saving. Herein, we present an approach for screening and diagnosis of these patients and focus on the importance of genetic testing.

Malignant Pheochromocytomas/Paragangliomas and Ectopic Hormonal Secretion: A Case Series and Review of the Literature

Malignant pheochromocytomas (PCs) and paragangliomas (PGLs) are rare neuroendocrine neoplasms defined by the presence of distant metastases. There is currently a relatively paucity of data regarding the natural history of PCs/PGLs and the optimal approach to their treatment. We retrospectively analyzed the clinical, biochemical, imaging, genetic and histopathological characteristics of fourteen patients with metastatic PCs/PGLs diagnosed over 15 years, along with their response to treatment. Patients were followed-up for a median of six years (range: 1–14 years). Six patients had synchronous metastases and the remaining developed metastases after a median of four years (range 2–10 years). Genetic analysis of seven patients revealed that three harbored succinate dehydrogenase subunit B/D gene (SDHB/D) mutations. Hormonal hypersecretion occurred in 70% of patients; normetanephrine, either alone or with other concomitant hormones, was the most frequent secretory component. Patients were administered multiple first and subsequent treatments including surgery (n = 12), chemotherapy (n = 7), radionuclide therapy (n = 2) and radiopeptides (n = 5). Seven patients had stable disease, four had progressive disease and three died. Ectopic hormonal secretion is rare and commonly encountered in benign PCs. Ectopic secretion of interleukin-6 in one of our patients, prompted a literature review of ectopic hormonal secretion, particularly from metastatic PCs/PGLs. Only four cases of metastatic PC/PGLs with confirmed ectopic secretion of hormones or peptides have been described so far.

[Biological diagnosis of pheochromocytoma: is there an interest in urinary metanephrines measurement over 3 consecutive days?]

Pheochromocytoma and paraganglioma are neuroendocrine tumors characterized by a catecholamine production potential. The biochemical diagnosis for this type of tumor is carried out through the metanephrine titration on 24-hours urines. Some authors have suggested that the sensitivity of the test could be improved by sampling and analyzing urines 3 days in a row (cycle) versus a unique measurement but this method has never been fully evaluated. The goal of this study was to establish a comparison of diagnosis performances between urinary metanephrines measurement for 3 consecutive days, and metanephrines measurement on a unique 24-hour sample. Patients of Brest Regional University Hospital whose 3-consecutive day 24-hour urine samples had been analyzed from January 2011 to May 2017 were included in this study. The primary endpoint was the comparison of diagnostic performances of urinary metanephrine titration over a single day versus 3 consecutive days. Eighty-two patients for a total of 103 cycles among which 7 revealed a pheochromocytoma were analyzed. ROC curve analysis shows that the metanephrine cycle titration method is more efficient than the metanephrine single titration method (metanephrine: AUC=0.881 against 0.826 respectively; normetanephrine: AUC=0.946 against 0.901 respectively). Urinary titration over 3 days allows the diagnosis of 100% (7/7) of pheochromocytomas against 85.7% (6/7) for the the single urinary titration. In conclusion, metanephrine titration over 3 consecutive days of 24-hours urine samples shows a better sensitivity and better diagnosis performances for detecting pheochromocytoma and paraganglioma than the single titration method.

Complete Remission in Metastatic Pheochromocytoma Treated with Extensive Surgery

Pheochromocytomas are rare neuroendocrine tumors that arise from chromaffin cells of the adrenal medulla. Malignant pheochromocytoma is defined as the presence of metastatic spread in tissues where chromaffin cells are not usually present. This case report describes the case of a relapsed malignant pheochromocytoma, spread to the right liver lobe, superior pole of the right kidney, posterior right hemidiaphragm, right hemidiaphragmatic pillar, inferior vena cava, and regional lymph nodes. After evaluation, an extensive surgery was performed, with resection of all the affected tissues and regional lymphadenectomy. No adjuvant treatment (radiotherapy or chemotherapy) was given. Complete clinical, biochemical, and radiological remission was achieved, with normalisation of metanephrine and normetanephrine. To date, six years after surgery, the patient remains asymptomatic and normotensive without taking any antihypertensive medication. We conclude that the therapeutic approach should be individualized in the case of metastatic pheochromocytoma. Extensive surgery can be considered as a treatment option, even in the case of multiple metastases, as it may be able to achieve complete remission of the disease, avoiding costly and potentially dangerous adjuvant therapies.