A young male presented to his general practitioner with labile hypertension ranging from 150/90 to 180/100 mmHg, while classic symptoms associated with elevated blood pressure were conspicuously absent. An investigation into secondary causes of hypertension revealed significantly elevated levels of serum normetanephrine.

Abdominal and pelvic CT imaging and subsequent 68Ga DOTATATE PET/CT scan identified an ellipsoid mass suggestive of an Organ of Zuckerkandl paraganglioma, confirmed by an MRI scan.

After the biochemical and radiological confirmation of paraganglioma, the patient underwent successful open tumor excision through a laparotomy approach. The biopsied tissues were analyzed histopathologically, which confirmed the diagnosis of a sympathetic paraganglioma.

Histopathology Report

Macroscopic description:
Brown to pale-tan tissue weighing 9g and measuring 38 x 22 x 20mm. Specimen inked blue and serially sectioned into 8 slices. The cut surface consists of a well circumscribed tan and homogeneous mass that measures 20 x 15 x 36mm and appears to be encapsulated. The capsule measures up to 1mm in thickness.

Microscopic description: 
The tumor is composed of nests of epithelioid tumor cells separated by thin network of capillaries and inconspicuous sustentacular cells, in keeping with the typical 'zellballen' architecture. The tumor cells have abundant eosinophilic cytoplasm, many with intracytoplasmic vacuoles and areas of clearing. There is some nuclear variability; most cells have round to ovoid nuclei with fine to coarsely granular chromatin, some with distinct nucleoli. Mitoses are present (up to 6 per 10 hpf). There is no necrosis.

Background and Review

Paragangliomas are rare neuroendocrine tumors that originate from neuroendocrine cells in extra-adrenal autonomic paraganglia, often leading to symptoms such as hypertension and headaches due to the secretion of catecholamines ¹.

They can develop from either parasympathetic or sympathetic paraganglia, each with distinct clinical characteristics and locations. Notably, sympathetic paragangliomas frequently occur at the Organ of Zuckerkandl near the aortic bifurcation. About 33-50% of paragangliomas are associated with inherited syndromes and various genetic conditions ².

Despite their rarity and common categorization with pheochromocytomas, diagnosis involves a two-step process: biochemical assessment of urinary and plasma metanephrines and catecholamines, followed by a radiological evaluation of the tumor location using techniques like CT, angiography, MRI, and PET scans ³.

Learning Points

Diagnostic Challenges:
Paragangliomas, especially those in the organ of Zuckerkandl, are difficult to diagnose due to their rarity and often non-specific presentation. The case discussed in the report involved a patient with only resistant hypertension as a symptom, underscoring the importance of considering uncommon causes of hypertension, especially in younger patients with no other risk factors. The diagnostic process often requires multiple imaging modalities and the interpretation of these findings can be challenging.

Multidisciplinary Management:
The management of paragangliomas requires a multidisciplinary approach involving general practitioners, radiologists, endocrinologists, and vascular surgeons. Medical management, initially focused on antihypertensive therapy, was unsuccessful due to the underlying catecholamine-producing tumor. Consequently, the treatment protocol evolved to surgical management, informed by the size and location of the tumor at the aortic bifurcation.

Recurrence and Surveillance:
Despite successful surgical resection, there is a risk of recurrence, especially in patients with multiple tumors, metastatic disease, familial paraganglioma, or extra-adrenal tumors. As such, lifelong follow-ups are crucial.