Non-functioning pancreatic neuroendocrine tumours

Non-functioning pancreatic neuroendocrine tumours

Definition P-NETs are clinically classified as non-functioning (NF-P NET) when they do not cause a clinical syndrome. Incidence NF-P-NETs account for 60–90% of all P-NETS. Pathology NF-P-NETs cannot be distinguished from functional tumours by immunocytochemistry because they may also express hormones such as gastrin and insulin. They usually stain posi tively for chromogranin A and synaptophysin. The tumours are usually large (>5 /uni00A0 cm) and unifocal except in MEN /uni00A0 1 syndrome. T hey are distributed throughout the pancreas with a head to body to tail ratio of 7:1:1.5. Clinical presentation They are generally diagnosed at a more advanced stage owing to their indolent nature, slow growth and lack of functional secretion causing a delay in the onset of symptoms. Therefore, in contrast to functioning PETs, patients with NF-PETs pres - ent with various non-specific symptoms, including jaundice, abdominal pain, weight loss and pancreatitis. In some cases liver metastases are the fir st presentation. - Diagnosis Increased levels of chromogranin A and PP are usual. The majority of these tumours are large and are easily identified by transabdominal ultrasonography or CT scanning. Di ff erenti - ation from the more aggressive pancreatic adenocarcinoma is extremely important (see Chapter 72 ) . Recognition of NF-P- NETs is imperative because of their resectability and excellent long-term survival compared with their exocrine counterparts. - Treatment (medical and surgical) For grade 1 and 2 unresectable tumours, SSAs may be e ff ective because of their antiproliferative properties. Alternatively novel targeted drugs (everolimus and sunitinib) could be considered. Platinum-based chemotherapy is the treatment of choice for grade 3 and NEC tumours. The algorithm for the management is summarised in Figure 57.16 .

Tumour <2 cm EUS, MRI every Option 1 6–12 months Surveillance Grades 1 and 2 No change – surveillance Option 2 Increase in size or Surgery

2 cm – surgery Grade 2, symptoms, patient’s wishes Tumour >2 cm Surveillance depending Surgery on final pathology Limited resection only if conditions favourable to preserve organ function SSA therapy Grade 2, progressive disease, symptoms SSTR negative – or high tumour burden chemotherapy Systemic platinum-based NEC, grade 3 therapy