EUS Unveils the Hidden: A Rare Encounter with Retrocaval Paraganglioma

Background: Paragangliomas are rare neoplasms arising from neural crest cells. Confirmatory diagnosis is possible by histology and Immunohistochemistry. Nonfunctional tumors in atypical locations pose diagnostic challenge. EUS offers sampling abdominal lesions in difficult locations but limited literature exists on its role in diagnosing paragangliomas.

Case presentation: A 55-year-old female, presented with one month history of lower abdominal pain, anorexia and weight loss. Past history of hypertension for 5 years, controlled on mono-therapy. No family history of malignancy. Physical examination was unremarkable. Prior treatment included ATT for cecal ulcers and sub-centimetric mesenteric lymphadenopathy. CECT abdomen showed an enlarged node posterior to the intrahepatic IVC abutting caudate lobe of liver and right crus of diaphragm. Tumor markers normal. With differential diagnosis of tuberculosis, lymphomas, carcinoma of unknown primary, patient underwent EUS which revealed 3X4 cm heteroechoic mass lesion posterior to intrahepatic IVC around the caudate lobe. FNA taken using 22G needle revealed neoplastic lesion. Immunocytochemistry positive for synaptophysin and GATA 3, negative for cytokeratin with Ki 67 <1%, confirming paraganglioma. Plasma metanephrines normal. FDG PET CT showed no FDG avidity outside of the mass. Patient underwent enbloc resection of tumor 4 × 2 cm with intraoperative hypertension controlled with nitroglycerin. Recovery uneventful. Histopathology confirmed paraganglioma.

Conclusion: Paragangliomas arise from ganglia of sympathetic and parasympathetic nervous system. Common site in abdomen is paraaortic axis, usually presenting with symptoms of catecholamine excess (paroxysms of palpitation/sweating/tachycardia/hypertension). Diagnosis of functional paragangliomas is relatively easy but it becomes challenging when its nonsecretory with unusual location like ours. With EUS, acquiring samples even in difficult location has become feasible. Hypertensive crises are reported with functional paragangliomas and should be avoided in them. However, with nonsecretory paragangliomas diagnosis is usually not anticipated and depends hugely on FNA. Surgical resection is the mainstay of treatment in localized disease.

Publication History

Article published online:
22 April 2024