Figure 1
Fig.1
On T1-w and T2-w MRI there is evidence of a large, well marginated isointense lesion involving the body and tail of the pancreas.
Low grade neuroendocrine carcinoma of the pancreas
SectionAbdominal imaging
Case TypeClinical Cases
AuthorsBattaglia V, Brunu M, Zingoni G, Bonechi C, Signorini F, Nardini L, Bartolozzi C
Connected authors
69 years, female
Clinical History
A 69-year-old woman presented with strong abdominal pain of the epigastrium, lasting for 2 months. Moreover, she complained about weight loss of 5 kg in the last 3 months. The clinical history for any previous abdominal pathology was negative.
Imaging Findings
The patient underwent an ultrasound (US) examination of the abdomen, which showed a large, inhomogeneous hypoechoic lesion in the pancreatic body-tail.
Hematological examinations resulted to be within the normal values; CA 19.9 was also normal (20,1 U/ml).
The patient then underwent a Magnetic Resonance (MRI) examination which included baseline T1-w and T2-w images and a post-contrast study after the intravenous injection of a hepatobiliary contrast agent (Gd-EOB-DTPA). On MRI baseline sequences, the lesion was isointense both on T2-w and T1-w images (Fig. 1). On the dynamic post-contrast sequences, the lesion showed partially an exophytic growth, joining the lesser curvature of the stomach, and measured 7 x 5,5 x 3,5 cm. On arterial phase, the lesion enhancement was inhomogeneous (Fig. 2). On portal venous and late phases, the lesion showed a slight wash-out (Fig. 3), and an infiltration and complete obstruction of the splenic vein became visible (Fig. 4). Moreover, the cholangiographic sequences showed a segmental obstruction of the main pancreatic duct (Fig. 5).
Computed Tomography (CT) examination, performed before and after intravenous administration of a contrast agent with high iodine concentration confirmed the results of MRI (Fig. 6). No distant involvement within liver parenchyma was found.
On the basis of the MRI and CT findings, a neuroendocrine pancreatic tumour was suspected.
The patient then underwent a left spleno-pancreatectomy.
Histology yielded a low-grade neuroendocrine carcinoma of the pancreas with peripancreatic tissue infiltration and neoplastic embolisation of peritumoral vessels.
The immunohistochemical examination resulted positive for chromogranin (Fig. 7).
Hematological examinations resulted to be within the normal values; CA 19.9 was also normal (20,1 U/ml).
The patient then underwent a Magnetic Resonance (MRI) examination which included baseline T1-w and T2-w images and a post-contrast study after the intravenous injection of a hepatobiliary contrast agent (Gd-EOB-DTPA). On MRI baseline sequences, the lesion was isointense both on T2-w and T1-w images (Fig. 1). On the dynamic post-contrast sequences, the lesion showed partially an exophytic growth, joining the lesser curvature of the stomach, and measured 7 x 5,5 x 3,5 cm. On arterial phase, the lesion enhancement was inhomogeneous (Fig. 2). On portal venous and late phases, the lesion showed a slight wash-out (Fig. 3), and an infiltration and complete obstruction of the splenic vein became visible (Fig. 4). Moreover, the cholangiographic sequences showed a segmental obstruction of the main pancreatic duct (Fig. 5).
Computed Tomography (CT) examination, performed before and after intravenous administration of a contrast agent with high iodine concentration confirmed the results of MRI (Fig. 6). No distant involvement within liver parenchyma was found.
On the basis of the MRI and CT findings, a neuroendocrine pancreatic tumour was suspected.
The patient then underwent a left spleno-pancreatectomy.
Histology yielded a low-grade neuroendocrine carcinoma of the pancreas with peripancreatic tissue infiltration and neoplastic embolisation of peritumoral vessels.
The immunohistochemical examination resulted positive for chromogranin (Fig. 7).
Discussion
Neuroendocrine tumors (NET) are rare neoplasms (0.5-1% of all human malignancies) arising predominantly from the pancreatic islets of Langerhans or from intraparenchymal APUD cells. They generally occur in the 4-6 decade in case of single sporadic neoplasm; otherwise they generally occur earlier (1-3 decade), especially if associated with genetic syndromes, such as MEN1, VHL, and others.
Approximately 15–20% of islet cell tumours do not secrete any hormones and are called non-secreting tumours. If there is evidence of an endocrine syndrome, they are classified as functioning neoplasms; in these cases, they may secrete one or more biologically active peptides, such as insulin, gastrin, VIP, glucagon and others [1].
Histologically, NET are classified into well differentiated tumours, low grade carcinomas (generally measuring > 2 cm), and high grade carcinomas [2].
Imaging modalities, in particular CT and MRI, may allow a correct differential diagnosis.
At MRI islet cell tumours generally appear hypointense on T1-w and hyperintense on T2-w images, due to the large amount of cellular content within the lesion.
On dynamic postcontrast studies, both after gadolinium chelates or iodinated contrast agents, they frequently show hypervascularity in the arterial phase and wash-out in the subsequent phases, due to the high amount of vessels and vascular shunts within the lesions. Sometimes, especially in large inhomogeneous masses, calcifications may occur [3].
The differential diagnosis may be challenging. In large neuroendocrine masses it includes focal autoimmune pancreatitis, which is characterized by a delayed contrast enhancement of the mass and loss of normal glandular architecture, without signs of vascular invasion. The rare hypervascular ductal adenocarcinomas represent another differential diagnosis; they are characterized by early infiltration of peri-glandular structures, early metastatic dissemination and lymph node involvement.
Finally, metachronous hypervascular metastases (particularly from renal carcinomas) must be considered in the differential diagnosis, especially in patients previously submitted to surgery. In these cases, a clue for diagnosis may be multiple localisations within the glandular parenchyma and/or high inhomogeneous enhancement of the lesions, often associated with large necrotic, central areas.
The treatment of pancreatic neuroendocrine tumours depends on their clinical and radiological features. In patients with a single lesion surgical resection is indicated, while in case of multiple lesions therapy with somatostatin analogs (octreotide) is the most common treatment. Patients with hypervascular ductal adenocarcinoma undergo duodeno-pancreatectomy. Autoimmune pancreatitis is the only pancreatic disorder responding to steroids.
Approximately 15–20% of islet cell tumours do not secrete any hormones and are called non-secreting tumours. If there is evidence of an endocrine syndrome, they are classified as functioning neoplasms; in these cases, they may secrete one or more biologically active peptides, such as insulin, gastrin, VIP, glucagon and others [1].
Histologically, NET are classified into well differentiated tumours, low grade carcinomas (generally measuring > 2 cm), and high grade carcinomas [2].
Imaging modalities, in particular CT and MRI, may allow a correct differential diagnosis.
At MRI islet cell tumours generally appear hypointense on T1-w and hyperintense on T2-w images, due to the large amount of cellular content within the lesion.
On dynamic postcontrast studies, both after gadolinium chelates or iodinated contrast agents, they frequently show hypervascularity in the arterial phase and wash-out in the subsequent phases, due to the high amount of vessels and vascular shunts within the lesions. Sometimes, especially in large inhomogeneous masses, calcifications may occur [3].
The differential diagnosis may be challenging. In large neuroendocrine masses it includes focal autoimmune pancreatitis, which is characterized by a delayed contrast enhancement of the mass and loss of normal glandular architecture, without signs of vascular invasion. The rare hypervascular ductal adenocarcinomas represent another differential diagnosis; they are characterized by early infiltration of peri-glandular structures, early metastatic dissemination and lymph node involvement.
Finally, metachronous hypervascular metastases (particularly from renal carcinomas) must be considered in the differential diagnosis, especially in patients previously submitted to surgery. In these cases, a clue for diagnosis may be multiple localisations within the glandular parenchyma and/or high inhomogeneous enhancement of the lesions, often associated with large necrotic, central areas.
The treatment of pancreatic neuroendocrine tumours depends on their clinical and radiological features. In patients with a single lesion surgical resection is indicated, while in case of multiple lesions therapy with somatostatin analogs (octreotide) is the most common treatment. Patients with hypervascular ductal adenocarcinoma undergo duodeno-pancreatectomy. Autoimmune pancreatitis is the only pancreatic disorder responding to steroids.
Differential Diagnosis List
Low grade neuroendocrine carcinoma of the pancreatic body-tail.
Final Diagnosis
Low grade neuroendocrine carcinoma of the pancreatic body-tail.
References
[1] Ehehalt F, Seager HD, Schmidt CM (2009) Neuroendocrine tumors of the pancreas, Oncologist 14:456-67. (PMID: 19411317)
[2] Rha SE, Jung SE, Lee KH (2007) CT and MR imaging findings of endocrine tumor of the pancreas according to WHO classification. Eur J Radiol 62:371-7. (PMID: 17433598)
[3] Horton KM, Hruban RH, Yeo C, Fishman EK (2006) Multi-detector row CT of pancreatic islet cell tumors. Radiographics 26:453-64. (PMID: 16549609)
[4] Desai KK, Khan MS, Toumpanakis C (2009) Management of gastroentero-pancreatic neuroendocrine tumors (GEP-NETs). Minerva Gastroenterol Dietol 55:425-43. (PMID: 19942827)
Case information
| URL: | https://eurorad.org/case/8108 |
| DOI: | 10.1594/EURORAD/CASE.8108 |
| ISSN: | 1563-4086 |
Figure 2
fig.2
On arterial phase dynamic MRI diffuse enhancement of the lesion with a pseudocapsule is demonstrated.
Figure 3
Fig.3
The lesion shows wash-out on venous and late phase dynamic MRI.
Figure 4
fig.4
Infiltration and complete obstruction of the splenic vein by the pancreatic lesion.
Figure 5
Fig.5
The cholangiographic sequence (thickness 5 mm) visualizes the dilated main pancreatic duct at the level of the tail of the pancreas, while at the level of the head of the gland the diameter of the duct is normal.
Figure 6
fig.6
CT confirmes the MRI findings. Coronal oblique post processed image shows in detail the complete thrombosis of the splenic vein. The splenic mesenteric junction appears patent.
Figure 7
Fig.7
At histology, the cells of the lesion resulted to contain chromogranine (staining with DiaminoBenzilguanidine).
Fig.1
On T1-w and T2-w MRI there is evidence of a large, well marginated isointense lesion involving the body and tail of the pancreas.
fig.2
On arterial phase dynamic MRI diffuse enhancement of the lesion with a pseudocapsule is demonstrated.
Fig.3
The lesion shows wash-out on venous and late phase dynamic MRI.
fig.4
Infiltration and complete obstruction of the splenic vein by the pancreatic lesion.
Fig.5
The cholangiographic sequence (thickness 5 mm) visualizes the dilated main pancreatic duct at the level of the tail of the pancreas, while at the level of the head of the gland the diameter of the duct is normal.
fig.6
CT confirmes the MRI findings. Coronal oblique post processed image shows in detail the complete thrombosis of the splenic vein. The splenic mesenteric junction appears patent.
Fig.7
At histology, the cells of the lesion resulted to contain chromogranine (staining with DiaminoBenzilguanidine).