Non-Functional Pancreatic Paraganglioma: A Diagnostic Masquerade

Background: Primary pancreatic or peri‑pancreatic paragangliomas are exceedingly rare extra‑adrenal neuro‑endocrine tumours, with fewer than 60 well‑documented cases reported [1]–[3]. Because most are non‑functional and radiologically mimic pancreatic neuro‑endocrine tumours or complex cystic lesions, pre‑operative diagnosis is notoriously difficult [4],[7],[11].Case presentation: We describe a 63‑year‑old man who presented with six months of worsening chronic epigastralgia and unquantified weight loss. Routine laboratory tests, including CA 19‑9 and CEA, were normal. Cross‑sectional imaging (ultrasound, contrast‑enhanced CT and MRI) demonstrated a 4‑cm, well‑circumscribed, mixed cystic–solid, hyper‑vascular mass in the duodeno‑pancreatic groove compressing—but not invading—the inferior vena cava. Endoscopic ultrasound clarified the multilocular cystic architecture, yet fine‑needle aspiration was deferred because of vascular proximity and low diagnostic yield. The patient underwent pancreas‑preserving en bloc excision via midline laparotomy; intra‑operative haemodynamics remained stable.Histopathology: Microscopy revealed classic “Zellballen” nests of uniform chief cells within a rich vascular stroma. Immunohistochemistry showed strong, diffuse expression of chromogranin A and CD56, with negative cytokeratin AE1/AE3, DOG1 and CD117, and a Ki‑67 index < 1 %, confirming non‑functional paraganglioma [2],[7]. Resection margins were clear (R0) and no metastatic lymph‑nodes were identified. The patient remains disease‑free 18 months post‑operatively.Discussion: This case underscores the diagnostic challenges posed by pancreatic paragangliomas, which often lack catecholamine‑related symptoms and display non‑specific imaging features. Differentiation from pancreatic neuro‑endocrine tumours relies on a keratin‑negative immunoprofile [7]. Complete surgical excision with negative margins is the treatment of choice [8],[2]; however, because malignant potential cannot be predicted histologically, prolonged surveillance is recommended [2],[4],[8].Conclusion: Pancreatic paraganglioma, though exceptionally uncommon, should be considered in the differential diagnosis of well‑vascularised cystic‑solid pancreatic masses with normal tumour markers. Awareness of this entity facilitates timely surgical management and appropriate long‑term follow‑up.