Paraganglioma, a kind of pheochromocytoma originating from embryonic neural crest, is a rare neuroendocrine neoplasm commonly located at extra-adrenal areas such as head, neck, and abdomen. There are a few reports on renal paragangliomas; fewer than 5 reported cases are renal pelvic paragangliomas, including our case.
Our patient, who had not experienced headache, hypertension, or palpitation, was founded to have a fixed mass in the left renal pelvis incidentally. Ultrasonography and computed tomography (CT) demonstrated a heterogeneous mass before surgery, and histopathologic test subsequently revealed that the infrequent mass was paraganglioma.
During 6 months follow-up, ultrasonography and CT examinations showed no signs of recurrence or metastasis.
The present case report confirms surgery as the standard to treat patients with paraganglioma. We present this case to serve as a reminder of suspected paraganglioma when it has occurred in renal pelvis.
Post author correction
Article Type: CASE REPORT
AuthorsCheng Yi, Lin Han, Rui Yang, Junfeng Yu
- • Accepted on 04/07/2017
- • Available online on 07/08/2017
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Extra-adrenal paraganglioma, a peculiar neuroendocrine tumor derived from chromaffin cells, can be observed at various anatomic locations such as the skull base, neck, thorax, and abdomen. The clinical symptoms of most paragangliomas include headache, hypertension, heart palpitation, and pain due to excessive secretion of catecholamine (1). Paraganglioma of renal pelvis presents without the specific symptoms, except a painless mass is very uncommon. Patients may not be diagnosed until intrarenal biopsy during the perioperative period, which results in detrimental consequences.
We present a case of a 24-year-old man with primary paraganglioma in the left renal pelvis. This study aims to report the diagnosis, treatment, and histopathology considered with a related literature review of the rare tumor.
The patient was a 24-year-old man who had a left renal mass noted incidentally during a medical examination at the People’s Hospital of China Three Gorges University (Yichang, China) in March 2016. Ultrasonography performed on the patient showed a left kidney mass (9.4 × 5.9 cm) located in the site of left renal pelvis with blood signs. Nevertheless, he had no history of headache, sweating, hypertension, or lumbar pain, and laboratory examinations included routine blood urinary, function of liver and kidney, and serum catecholamine indicated no abnormality. He was admitted.
A plain computed tomography (CT) scan of the patient’s upper abdomen demonstrated a heterogeneous mass (7.6 × 5.9 cm) in the left renal area involving the pelvicalyceal system (
Based on these tests, the patient was diagnosed with a left renal pelvic tumor provisionally and underwent left radical nephrectomy by transperitoneal laparotomy. At operation, the mass was at the middle and lower pole of the left kidney, involving the renal pelvis. Renal artery was then interim blocked and radical excision of the left kidney was done owing to the tumor being almost in the renal parenchyma. Notably, the cut section showed a chocolate brown part measuring 9 × 5 × 4.5 cm in the renal pelvis and another brown yellow spherical one (4 × 3 × 1.5 cm) at the middle pole of the kidney outside the renal capsule; both of the parts had well-defined borders but were conterminous in the renal pelvis (
Surgical specimen of left renal pelvis.
Pathologic examination suggested that the tumor was a paraganglioma with high ratio of nucleus to cytoplasm but well-differentiated (
Ethics statement and consent
All data involving this patient were obtained in accordance with the ethical standards of The First People’s Hospital of China Three Gorges University and approved by the Experimental Human Management Committee of China Three Gorges University and The First People’s Hospital of China Three Gorges University. Informed consent was obtained from the patient before publication of this case report.
Paraganglioma originating from chromaffin-producing neural crest tissue is usually located at the site of distal aortic bifurcation associated with the sympathetic chain. In the genitourinary tract, renal pelvis (4.9%) is the third primary site of paragangliomas, following behind the bladder (79.2%) and urethra (12.7%) (2). It has been reported that 97% of paragangliomas were considered benign and occurred more frequently in women between 30 and 40 years of age (3). In accordance with the capability of catecholamine levels, paragangliomas can be classified as functional and nonfunctional types. The former types are commonly linked with sharp headache, intermittent hypertensive attack, and palpitations owing to high levels of catecholamine, whereas the latter is asymptomatic (1). To our knowledge, there are few reports on renal paragangliomas, whereas only 2 cases are renal pelvic paragangliomas, including our case (4).
It is not easy to make a diagnosis of renal pelvic paraganglioma prior to operation owing to lack of specific clinical symptoms. However, ultrasonography, CT, 131I-metaiodobenzylguanidine, and magnetic resonance imaging is beneficial to describe the region of paraganglioma; positron emission tomography is more accurate to trace and estimate the lesions of primary and metastasis and its characteristics (5). Furthermore, endocrine examination including catecholamine and noradrenaline in serum and 24-hour urine should be performed when renal pelvic paraganglioma is suspected. Patients with functional mass may have increased levels of catecholamine and noradrenaline in blood and urine (6). Nevertheless, 10%-15% patients with such nonfunctioning tumor and normal hormone levels may remain undiagnosed in the preoperative period (7). Such a conclusion was verified in our case.
It has been documented that surgical operation was the most optimal treatment for renal pelvic paraganglioma, functional or nonfunctional (8). Notably, α-receptor antagonist should be administered to stabilize hypertension before operation and avoid hypertensive crisis occurring throughout the surgical procedure when patients are suspected to have functional paragangliomas (2).
Commonly, diagnosis of paraganglioma is determined by histopathologic examination. Consistent with other cases (2, 9), the tumor cells were surrounded by sustentacular cells and separated into polygonal nests by fibrovascular stroma in the present case. Immunohistochemistry is also critical to further support the diagnosis of paraganglioma with positivity for CgA, PCK, CD56, and S-100 protein. That the mass was negative for CgA, a type of neuroendocrine secretory protein, suggested that the paraganglioma of this study was nonfunctional.
However, it is difficult to distinguish whether the paraganglioma is benign or malignant on microscopic inspection unless it infiltrates nearby organs or spreads to distant spots. Therefore, surveillance and follow-up are warranted due to its potential recurrence.
In summary, surgery remains the standard to treat patients with paraganglioma, though there are limited ways to diagnose it at the preoperative period. Due to its rarity in the literature, we present this case to serve as a reminder of suspected paraganglioma when it has occurred in renal pelvis.
- Yi, Cheng [PubMed] [Google Scholar] 1
- Han, Lin [PubMed] [Google Scholar] 2
- Yang, Rui [PubMed] [Google Scholar] 1
- Yu, Junfeng [PubMed] [Google Scholar] 1, * Corresponding Author (email@example.com)
Department of Urology, The First People’s Hospital of Yichang, China Three Gorges University, Yichang, Hubei - China
Department of Pathology, The First People’s Hospital of Yichang, China Three Gorges University, Yichang, Hubei - China