A rare case of intra-renal paraganglioma in a child masquerading as renal cell carcinoma

Aditya Arvind Manekar; Subrat Kumar Sahoo; Bikasha Bihary Tripathy; Prasant Nayak; Mukund Namdev Sable; Manoj Kumar Mohanty

doi:10.4103/ipcares.ipcares_193_22

CASE REPORT

Year : 2023 | Volume : 3 | Issue : 1 | Page : 31-34

A rare case of intra-renal paraganglioma in a child masquerading as renal cell carcinoma

Aditya Arvind Manekar¹, Subrat Kumar Sahoo¹, Bikasha Bihary Tripathy¹, Prasant Nayak², Mukund Namdev Sable³, Manoj Kumar Mohanty¹
¹ Department of Paediatric Surgery, All India Institute of Medical Sciences, Bhubaneswar, Odisha, India
² Department of Urology, All India Institute of Medical Sciences, Bhubaneswar, Odisha, India
³ Department of Pathology, All India Institute of Medical Sciences, Bhubaneswar, Odisha, India

Date of Submission	19-Aug-2022
Date of Decision	17-Jan-2023
Date of Acceptance	21-Jan-2023
Date of Web Publication	27-Feb-2023

Correspondence Address:
Dr. Bikasha Bihary Tripathy
Department of Paediatric Surgery, All India Institute of Medical Sciences, Bhubaneswar - 751 019, Odisha
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/ipcares.ipcares_193_22

Abstract

Background: Renal cell carcinomas (RCCs) are rare in children, accounting for around 2% of all pediatric renal tumors. Paragangliomas are extra-adrenal locations of phaeochromocytomas. They originate from chromaffin cells arising along the sympathetic paraganglia and are secretory in most cases. Sequential imaging is often required to ascertain the etiology of a renal mass; ultrasound (USG), contrast-enhanced computerized tomography scan (CECT), and magnetic resonance imaging (MRI). Tissue diagnosis is confirmatory. Clinical Description: An 11-year-old girl presented with a right-sided abdominal and flank pain that was dull aching and nonradiating. She had no history of jaundice, hematuria, dysuria, bowel symptoms, sweating, palpitations, or syncope. The vitals were stable, without tachycardia or hypertension. No abnormal findings were found on clinical examination. Initially, the possibility of a renal stone was considered. Management and Outcome: Baseline blood tests were normal. Abdominal USG detected a heterogeneous mass in the right kidney. CECT ascertained that it was very vascular and exhibited contrast enhancement, suggesting a renal tumor. MRI showed that the right renal artery was acting as the feeding vessel to the tumor. RCC was suspected based on imaging. The vascular nature prevented us from performing a Tru-cut biopsy. A right-sided nephrectomy was planned, preceded by angiography and embolization of the right renal artery to reduce vascularity. Intraoperative episodes of hypertension were noted. Gross appearance suggested RCC; however, histopathology revealed evidence of an intrarenal PGL. Conclusions: Diagnosing a nonfunctional PGL in an asymptomatic patient is challenging and may only be possible by intraoperative histopathology.

Keywords: Adrenal tumor, chromaffin, hypertension, renal tumor

How to cite this article:
Manekar AA, Sahoo SK, Tripathy BB, Nayak P, Sable MN, Mohanty MK. A rare case of intra-renal paraganglioma in a child masquerading as renal cell carcinoma. Indian Pediatr Case Rep 2023;3:31-4

How to cite this URL:
Manekar AA, Sahoo SK, Tripathy BB, Nayak P, Sable MN, Mohanty MK. A rare case of intra-renal paraganglioma in a child masquerading as renal cell carcinoma. Indian Pediatr Case Rep [serial online] 2023 [cited 2023 Mar 22];3:31-4. Available from: http://www.ipcares.org/text.asp?2023/3/1/31/370529

Renal cell carcinoma (RCC) is a rare malignancy occurring in approximately 2%–12% of the pediatric population.^[1],[2] It is the most common renal malignancy in the second decade of life, with the median age of the presentation reportedly between 10.6 and 17 years.^[1] Paragangliomas (PGL) are rare neuroendocrine tumors that arise from neural crest-derived cells or organs (paraganglia) and can occur in the base of the skull, neck, thorax, and abdomen. Positive immunostaining for chromogranin A is indicative of the neuroendocrinal origin.^[3],[4],[5] The lesions emit catecholamines into the circulation triggering hypertension, headaches, diaphoresis, palpitations, and tremors.

The nonspecificity of symptoms makes establishing the diagnosis of PGL, especially challenging,^[5] and imaging plays a very important role. There is no specific feature on imaging for PGL; though vascularity of the tumor shows classical hyperenhancing lesions, these may not always be seen.^[6] We present a child with an intrarenal PGL who was initially diagnosed and managed as RCC. Our aim is to share the diagnostic dilemmas that we faced, and the clinical reasoning that was applied to reach the final diagnosis.

Clinical Description

An 11-year-old girl presented to our outpatient department with symptoms of intermittent right-sided abdominal pain for 2 months. The pain was insidious in onset, dull aching, and intermittent in nature, and localized predominantly in the right flank region. The pain was mild in severity, with no radiation elsewhere. The child had been managed with antispasmodic medications at other hospitals, with no symptomatic relief. The child had no history of any fever, bowel or urinary complaints, jaundice, hematuria, or significant weight loss. She did not have any symptoms of sweating, palpitations, or syncope. There were no similar episodes in the past. The family belonged to a lower socioeconomic class. She was immunized completely according to her age.

The clinical examination was unremarkable. Her temperature was normal (98.2°F), heart rate was 88 beats/min, respiratory rate was 20 breaths/min, and blood pressure was 110/72 mmHg (normotensive). Her weight was 37 kg (50–75^th percentile), height 144 cm (50–75^th percentile), and body mass index 17.8 kg/m² (50–75^th percentile). There was no pallor, icterus, cyanosis, clubbing, or edema of the feet or body. The skull and spine appeared normal. Sexual maturity rating was appropriate for age. The abdominal examination was soft, without any palpable mass, organomegaly, or free fluid. External genitalia and hernial sites were normal. The rest of the systemic examination (respiratory, cardiovascular, and nervous system) was normal. Since the clinical examination was not contributory, based on the nature and localization of the pain, we initially kept the possibility of kidney stones (right sided). To confirm our suspicions, we planned blood tests (as mentioned below) and ultrasound (USG) of the abdomen and the kidney.

Management and outcome

Blood investigations showed normal hemoglobin level of 13.4 g/dL, white blood cell count 8500/cu mm with normal differential count, and a serum creatinine level of 0.8 mg/dL (within the normal range). The abdominal USG revealed a heterogeneous mass within the right kidney, 5 cm × 6 cm in dimensions with high internal vascularity. The contralateral kidney and the rest of the abdomen appeared normal. This highly vascular mass pointed toward the possibility of a renal tumor or renal vascular lesion (i.e., hemangioma, arteriovenous, or venous malformation). We proceeded with a contrast-enhanced computerized tomography scan of the abdomen for better anatomical delineation. This [Figure 1] demonstrated that the heterogeneous mass in the right kidney exhibited contrast enhancement which was suggestive of a renal tumor. Since the lesion appeared highly vascular, a Tru-cut biopsy could not be done. Magnetic resonance imaging (MRI) of the abdomen was planned instead to delineate the vascularity. This showed that the right renal artery was acting as the feeding vessel to the tumor. Thus, based on these imaging findings, we considered a provisional diagnosis of RCC. Other radiological differential diagnoses included renal vascular malformation or a cystic tumor of the kidney with some solid components.

Figure 1: (a) CECTscan showing a right- sided renal mass with increased vascularity; (b) the right renal mass. CECT: Contrast-enhanced computerized tomography

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Surgery was planned in the form of a right radical nephroureterectomy. However, the fact that the mass was highly vascular meant that there was a great risk of intraoperative bleeding. Therefore, the patient underwent a preliminary angiography and embolization of the right renal artery to reduce the vascularity of the tumor. This was followed by a right nephrectomy within 24 h. Intraoperatively, a highly vascular mass of approximately 5 cm × 6 cm size was seen adhered to the inferior surface of the liver, intrahepatic inferior vena cava, and the diaphragm posteriorly [Figure 2]. This gross appearance indicated a possible RCC, which was in alignment with our provisional diagnosis. During dissection, a small rent occurred in the inferior vena cava wall, which was immediately repaired. Intraoperative spikes of hypertension were noted during the handling of tumor during surgery. They were managed by the anesthetist by deepening the plane of anesthesia which lowered the blood pressure. The postoperative recovery period was uneventful.

Figure 2: The resected specimen and the tumor bed after excision of the mass

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Histopathological examination was performed on a mass of 6 cm diameter taken from the upper pole of the right kidney. The specimen revealed round to oval, mildly pleomorphic cells arranged in Zellballen pattern (i.e., a small nest of chromaffin cells or chief cells with pale eosinophilic staining) with fibrovascular septa and abundant granular eosinophilic cytoplasm [Figure 3]. This picture did not conform with RCC at all, and rather indicated a PGL. Post discharge, the child is doing well with no signs and symptoms of recurrence. She has been under regular follow-up for 2 years and has remained normotensive without the need for any medication.

Figure 3: Round to oval, mildly pleomorphic cells arranged in Zellballen pattern with fibro vascular septa, abundant granular eosinophilic cytoplasm. Areas of renal sinus confined to the kidney

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Discussion

RCC usually occurs between 50 and 70 years of age. It is extremely rare in children, with the incidence estimated to be 1.8% to 6.3% of all malignant renal tumors.^[7] The most common presentation in children is macroscopic hematuria and/or abdominal or flank pain (as seen in this case). Other less frequent symptoms are palpable abdominal mass, anemia, and fever. Its presentation as an incidental finding is less commonly seen than in adults.^[7],[8]

Imaging plays a very important role in the pretreatment assessment and follow-up (both during and after treatment) of all pediatric renal tumors including RCC. While pediatric RCC is commonly initially recognized by sonography, subsequent imaging with either contrast-enhanced, computed tomography (CT), or MRI is often deemed necessary to define the exact local extent of the neoplasm, identify the presence of lymph node metastasis, and detect distant metastatic disease.^[9] Features such as postcontrast enhancement pattern (homogeneous or heterogeneous), the presence or absence of internal calcification/ossification, the presence or absence of internal or adjacent hemorrhage, and the presence or absence of internal or adjacent neovascularity (abnormally dilated/tortuous blood vessels within or next to the mass) are seen in RCC, due to which a provisional diagnosis of RCC was considered in our patient.^[9]

Pheochromocytoma (PCC) and PGL are rare chromaffin cell tumors of neuroendocrine origin which secrete catecholamines and are a rare cause of secondary hypertension in the pediatric population.^[10] PCCs arise from the adrenal medulla and comprise 80%–85% of catecholamine-secreting tumors, whereas PGLs that arise from extra-adrenal locations are subdivided into sympathetic and parasympathetic PGLs, accounting for 15%–20% of these tumors. Sympathetic PGLs arise along the sympathetic ganglion chain in the chest, abdomen, and pelvis. Parasympathetic PGLs arise from parasympathetic tissue in the head-and-neck PGL; these rarely secrete catecholamines.^[10]

The renal pelvis (4.9%) is the third primary site of PGL; the first and second sites being the bladder (79.2%) and the urethra (12.7%). The most common variety of PGL is benign, frequently occurring in women between 30 and 40 years of age. They are classified into functional or nonfunctional depending on the catecholamine secretion. The manifestations in the former are commonly headaches, episodic hypertension, and palpitations, whereas the latter are asymptomatic.^[4] Around 10%–15% of cases nonfunctioning tumors with normal hormonal levels may remain undiagnosed. The imaging (CT and USG) findings pointed toward the diagnosis of RCC in this case. There are no criteria that can distinguish RCC from pheochromocytoma on CT imaging.^[5]

There is a paucity of data about the optimal treatment of the different subtypes of childhood RCC, though outcomes are comparable to adults.^[2] Surgical resection is the mainstay of therapy for RCC, given its intrinsic resistance to chemotherapy and radiation therapy.^[7] The concept of selective renal arterial embolization (RAE) was introduced for the reduction of RCC tumor mass, facilitation of surgery, and reduction in hematuria. This procedure of RAE has been advocated and used by many authors before surgery to decrease the intraoperative blood loss. This reduces the requirement for blood transfusion.^[11] The resultant preoperative infarction decreases tumor vascularity and allows the renal vein to be ligated early on in the operation, before the renal artery has been controlled, and thus alleviates the some of the technical difficulties of nephrectomy when there is tumor involvement of the renal hilus.^[12],[13] The optimal delay between embolization and operation should be less than a day to reduce the distress caused by postinfarction syndrome.^[13] However, there are schools of thought that do not agree with these benefits of RAE. In their study, May et al. found that preoperative RAE did not improve the survival, nor did it lead to a better prognosis in their patients with RCC.^[12]

Our patient underwent a right radical nephrectomy with a provisional diagnosis of right-sided RCC, which turned out to be an intrarenal PGL on histopathology. Only 15% of the patients of PGL remain asymptomatic; these patients are typically diagnosed during imaging conducted for other medical purposes. Only 1% of PGL are functional and produce catecholamines, with the majority being asymptomatic or having symptoms such as vague abdominal pain.^[14] The mainstay of the treatment of PGL is total resection when possible.^[6] Since this was done in our patient, there was a symptomatic improvement.

From this case, we would like to highlight the following facts. RCC is a rare tumor in pediatric patients, with no specific clinical features and imaging. A pediatric renal PGL is an extremely rare entity, which may be especially difficult to diagnose when nonfunctional, asymptomatic, and thus, not suspected (as in this case). In some cases, a final diagnosis can only be made postoperatively, after histopathology becomes available. Follow-up is important to monitor possible recurrence.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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