Sarcoidosis mimicking metastatic progression of pancreatic neuroendocrine tumor: A case report

RATIONALE: Pancreatic neuroendocrine tumors (PNETs) account for less than 5% of all pancreatic tumors. PNETs develop from pancreatic endocrine islet cells and have a variable range of malignant potential. These neoplasms tend to have a slower growth rate than exocrine tumors and may remain undetectable for years. Achieving a correct diagnosis and staging is of key importance for the optimal management of the disease and requires experience with the disease, an accurate clinical status evaluation and a critical interpretation of the radiological findings derived from morphological and functional imaging techniques as well as an integrated multidisciplinary approach. The possibility that some clinical data and radiological findings encountered during the diagnostic and staging procedures may not be related to PNETs but to concomitant clinical conditions should always be taken into consideration. This is mandatory as an incorrect stadiation may lead to patients’ mis-management. PATIENT CONCERNS: We report the case of a 34-year-old female, with a past medical history of idiopathic acute pancreatitis, presenting with a severe upper abdominal pain, steady and radiating to the back. DIAGNOSES: Initial investigations incidentally detected a nonfunctioning pancreatic neuroendocrine tumor (NF-PNET) of intermediate grade G2. Subsequent investigations aimed at determining a correct tumor staging showed a negative indium-111- OctreoScan but an increased 18F-labeled fluorodesossiglucose (18F-FDG) uptake in multiple bilateral nodules in the lungs and in 1 nodular lesion located in the right gluteal subcutaneous tissue. An early tumor progression of a G2 NF-PNET that had to be treated with chemotherapy was suspected. INTERVENTIONS: The histological examination of the gluteal subcutaneous nodule showed noncaseating granulomas, disproving the initial clinical suspect and allowing the diagnosis of active sarcoidosis in the G2 NF-PNET patient. LESSONS: A misdiagnosis and a consequent therapeutic mismanagement were avoided with the support of an integrated multidisciplinary team.