Background: Pheochromocytoma (PCC) and Paraganglioma (PGL) are rare neuroendocrine neoplasms. These tumors harbour disastrous consequences during surgery due to catecholamine hypersecretion if they are undiagnosed or prepared inadequately preoperatively. Case presentation: A 41-year-old lady presented with mild left flank discomfort. She had experienced recurrent anxiety attacks accompanied by palpitations and headache which were managed previously as panic attacks. Radiologic investigations showed a retroperitoneal mass that located anteromedial to the left kidney, separated from the left adrenal gland and adherent to the 4th duodenal segment. During admission, her vital signs showed slight elevation of blood pressure (140\90-160\110) mmHg, thus 24-h urine metanephrine and normetanephrine were requested and the results revealed normal values. Upper gastrointestinal endoscopy failed to pass beyond the 3th duodenal segment and showed no pathologic evidence. According to her findings, a diagnosis of duodenal gastrointestinal stromal tumor (GIST) was suspected. During laparotomy, crises of hypertension and tachycardia followed by severe hypotension made the resection of the misdiagnosed mass very tricky. Immunohistochemical staining studies confirmed the diagnosis of paraganglioma. Conclusion: Paraganglioma is a life threatening disease and should always be considered as a differential diagnosis of asymptomatic retroperitoneal mass. The aim of our study is to present a challenging case of an undiagnosed retroperitoneal paraganglioma and to alarm our colleagues from such troubles. Publisher's NoteSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Gastrointestinal stromal tumor is a rare neoplasm affecting gastrointestinal tract. Duodenal gastrointestinal stromal tumor originating from the fourth segment is considered an extremely rare disease. Surgical challenges arise when managing locally recurrent hemorrhagic duodenal gastrointestinal stromal tumor. A 58-year-old male presented with melena for the last 10 days. Thirty months previously, he had segmental resection of the fourth duodenal portion due to hemorrhagic gastrointestinal stromal tumor. No adjuvant imatinib therapy was administered (low risk for recurrence). The latest investigations showed actively bleeding tumor in the distal third portion of the duodenum, indicating a locally recurrent gastrointestinal stromal tumor. Uneventful emergent limited resection was performed. To the best of our knowledge, this is the first case report describing locally recurrent gastrointestinal stromal tumor in the distal duodenal portion. We will explain the therapeutic challenges and risk stratification and discuss gastrointestinal bleeding as a prognostic indicator for gastrointestinal stromal tumor recurrence.