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A 14-year-old girl came to our hospital because of uncharacteristic diffuse severe and persistent abdominal pain with nausea. She had no comorbidities and abdominal examination was unremarkable. Serum levels of elastase 1, carcinoembryonic antigen, carbohydrate antigen 19-9, pancreatic polypeptide, gastrin, insulin, vasoactive intestinal peptide, human chorionic gonadotropin, neuron-specific enolase and urinary catecholamines were normal. Abdominal CT scan showed a complex well-marginated round mass with cystic/necrotic degeneration on left flank, measuring 12.6 cm. Calcium foci were observed between the solid component and the liquefied area. Contrast-enhanced CT scan showed heterogeneous enhancement on the solid portion of the tumour (figure 1A), with late washout.
The lesion determined deviation of the left ureter, bowel and descending colon, without invasive behaviour. Dilated vessels were detected adjacent to the lesion.
Resection was not possible on the first attempt due to extensive neovascularisation. Therefore, a mass embolisation was performed before the surgical resection.
Macroscopically, the tumour had smooth outer surface, with a brownish dark red trabecular tissue and a multicystic central area. Non-malignant lymph nodes were removed.
Microscopically, there was no invasive behaviour (figure 1B). The tumour was positive for S-100 (sustentacular pattern), chromogranin A and synaptophysin. The Ki-67 labelling index was 20%.
What is the final diagnosis?
Non-functioning retroperitoneal paraganglioma.
Paragangliomas are tumours from the chromaffin cells with extra-adrenal location. Retroperitoneal paraganglioma is extremely rare (incidence of 0.02%), whose most common site is the organs of Zuckerkandl. They affect mainly adults in the fourth/fifth decade, with no sex predilection.1
Functioning tumours may present elevated serum levels of chromogranin A, neuron-specific enolase (NSE) or vimentin.
At CT scan, paraganglioma is seen as a well-defined tumour with areas of haemorrhage and necrosis with intense contrast enhancement. Punctate calcification and fluid–fluid levels may be seen. At MRI, these tumours are usually hypointense on T1-weighted images and markedly hyperintense on T2-weighted images.2 3
Administration of m-iodobenzylguanidine is a sensitive technique to localise functioning paragangliomas.4
Histologically, they have highly vascular appearance, with chief cells and sustentacular cells arranged in clusters (zellballen). Chief cells are often positive for neuroendocrine markers (synaptophysin, NSE, chromogranin) on immunohistochemistry, while sustentacular cells are positive for S-100 protein.5
Headache, palpitations, sweating and elevated urinary metanephrine/vanillylmandelic acid levels should appear on the functioning type. In the case of non-functioning paragangliomas, CT/MRI may help. Differential diagnoses include schwannoma, neurofibroma, ganglioneuroma, ganglioneuroblastoma, neuroblastoma and pheochromocytoma. Metastasis is rare, but possible. Thus, the follow-up included a post-operative CT scan, followed by a biannual ultrasound (US) for 2 years and annual US after that for 5 years. The patient remains asymptomatic with normal imaging examinations.
Contributors DBP planned the study. FNAM led the case. BCB collected clinical data and submitted the study.
Competing interests None declared.
Patient consent Parental/guardian consent obtained.
Provenance and peer review Not commissioned; externally peer reviewed.
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