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.

Rare neuroendocrine tumours: results of the surveillance of rare cancers in Europe project

Because of the low incidence, and limited opportunities for large patient volume experiences, there are very few relevant studies of neuroendocrine tumours (NETs). A large population-based database (including cancer patients diagnosed from 1978 to 2002 and registered in 76 population-based cancer registries [CRs]), provided by the project 'surveillance of rare cancers in Europe' (RARECARE) is used to describe the basic indicators of incidence, prevalence and survival of NETs, giving a unique overview on the burden of NETs in Europe. NETs at all cancer sites, excluding lung, were analysed in this study. In total over 20,000 incident cases of NETs were analysed and a data quality check upon specific NETs was performed. The overall incidence rate for NETs was 25/1,000,000 and was highest in patients aged 65 years and older with well differentiated endocrine carcinomas (non-functioning pancreatic and gastrointestinal) (40 per 1,000,000). We estimated that slightly more than 100,000 people were diagnosed with NETs and still alive in EU27 at the beginning of 2008. Overall, NETs had a 5 year relative survival of 50%; survival was low (12%) for poorly differentiated endocrine carcinoma, and relatively high (64%) for well differentiated carcinoma (not functioning of the pancreas and digestive organs). Within NETs, endocrine carcinoma of thyroid gland had the best 5-year relative survival (82%). Because of the complexity and number of the different disciplines involved with NETs (as they arise in many organs), a multidisciplinary approach delivered in highly qualified reference centres and an international network between those centres is recommended.

7. False Positives and False Negatives in Neuroendocrine Tumors Diagnosis: Clinical Reports

Differential diagnosis NETs may be highly challenging. In order to exclude conditions that may mimic a neuroendocrine neoplasms, a deep knowledge of all the aspects of the disease, together with an adequate capacity to interpret clinical data and imaging findings and to put them in right correlation, are strongly warranted. Patients which suspected neuroendocrine neoplasms should be referred to reference centers to receive optimal multidisciplinary care. Free full text available at www.tumorionline.it