Pancreatic (neuro)endocrine tumours

Histopathology

Most islet cell tumours have a characteristic "neuroendocrine" appearance. However, a number of unusual morphological appearances are seen in rare cases:

General immunohistochemistry

cytokeratin 7

rarely positive

cytokeratin 8

positive

cytokeratin 18

positive

cytokeratin 19

28/54, prognostically significant1

NSE

positive

PGP9.5

positive

synaptophysin

positive, including non-functioning tumours

chromogranin

positive, except in some non-functioning tumours

Leu-7

positive

prealbumin

positive

neurofilament

rarely positive

   

 

Specific tumour types

 

insulinoma

gastrinoma

glucagonoma

vipoma

insulin

positive

variable

 

 

proinsulin

positive

 

 

 

islet amyloid polypeptide

positive

 

 

 

gastrin

 

positive

 

 

PP

 

variable

often positive

often positive

glucagon

 

variable

often weak

 

proglucagon derivatives

 

 

often positive

 

VIP

 

 

 

usually positive

neurotensin

 

 

 

sometimes positive

calcitonin

 

 

 

sometimes positive

 

Prognosis

Predicting behaviour of pancreatic endocrine tumours is difficult. The Capella prognostic classification divides tumours into four categories:

 

Insulinoma or well differentiated tumour

<2 cm

benign

 

2-3 cm

borderline

> 3 cm or angio-invasion

low grade malignant

Gastrinoma or VIPoma or glucagonoma or with Cushing's syndrome or carcinoid syndrome

< 1 cm

benign

1-2 cm

borderline

> 2m or angio-invasion

low grade malignant

Highly atypical cells resembling small cell carcinoma

 any size

high grade malignant

     

 

In one study1, mitoses, necrosis, vascular invasion, perineural invasion and CK19 staining (but not Capella classification) were all prognostically significant on univariate analysis, but only CK19 staining was significant on multivariate analysis (p=0.0008).

 

 

Alive and well

died or alive with disease

 

CK19 negative

25/251

0/251

CK19 positive

10/231

13/231

     

 

Differential diagnoses

 

References

Diagnostic histopathology of tumors. Edited by CDM Fletcher. 2nd edition. Churchill Livingstone. Pages 1087-1091.

1Deshpande, V., C. Fernandez-del Castillo, et al. (2004). "Cytokeratin 19 is a powerful predictor of survival in pancreatic endocrine tumors." Am J Surg Pathol 28(9): 1145-53.

 

This page last revised 9.10.2004.