Pancreatic Pathology Online: An approach to reporting of pancreatic specimens

Reporting of pancreatic biopsies for the diagnosis of neoplastic lesions ; Reporting of ampullary and periampullary biopsies for the diagnosis of neoplastic lesions ; Reporting of Pancreaticoduodenectomy (Whipple's operation) specimen ; Reporting of Distal Pancreatectomy Specimen.

Specimens from the pancreas are rarely received outside specialist centers.

Biopsy specimens may be taken to establish whether there is a neoplasm of the pancreas, either as open biopsy at laparotomy, through an endoscope, especially if the tumour is ampullary, or percutaneously under radiological guidance.

Note: Pancreatic resections are performed for benign and malignant primary pancreatic tumors as well as for primary tumors arising within the common bile duct, ampulla of Vater and duodenum. In pancreatic cancer, accurate histopathology is essential not only for confirmation of malignancy but for the assessment of prognosis. There is some evidence that adjuvant therapy may improve survival in pancreatic carcinoma but histopathological factors are not currently widely used to determine postoperative treatment. However, accurate data collection is also important for audit and research purposes and in the future may be used as a direct guide for further management.

Large specimens comprise tissues from pancreatodenectomy (Whipple's operation), distal pancreatectomy and total pancreatectomy.

Partial pancreatectomy is usually the treatment for islet cell tumours as most occur in the body and tail of the pancreas, but Whipple's operation is occasionally necessary to remove a tumour in the head of the pancreas.

Specimen types:

-Standard Kausch-Whipple pancreatoduodenectomy

-Pylorus-preserving pancreatoduodenectomy

-Total pancreatoduodenectomy

-Left pancreatectomy

The most commonly encountered major pancreatic specimen is a standard or modified Kausch-Whipple pancreato-duodenectomy. This will include the head of the pancreas together with the duodenum, a variable quantity of distal stomach and the lower end of the common bile duct. The pylorus may be absent if a pylorus-preserving procedure has been performed. The gallbladder may be attached to the main specimen or received separately. A variable quantity of connective tissue will be present, containing lymph nodes, although some surgeons prefer separately to dissect the major lymph node groups. In case of multifocal pancreatic tumor, the specimen may occasionally contain the whole pancreas and rarely, the tail and/or body of the pancreas alone is received.

Frozen section diagnosis may be required to confirm suspicions raised by preoperative biopsies and ancillary investigations.

Intra-operative frozen sections may be performed to confirm the nature of the tumour or to assess the pancreatic surgical margin for evidence of tumour involvement.

Frozen sections may also be taken of possible metastatic deposits found at laparotomy.

Needle biopsies of the pancreas are most commonly are performed under image guidance during the investigation of a radiologically detected pancreatic lesion, or more rarely if a pancreatic lesion of unknown nature is identified at laparotomy.

The following clinical information should be provided to the histopathologist :

- Age and sex of the patient;

- Symptoms and their duration: Jaundice, malabsorption, abdominal pain, dizziness, fainting, mental confusion;

- History of alcohol intake ;

- History of previous pancreatitis ;

- Findings on CT, MRI, angiography, ERCP ;

- Results of biochemical investigation: liver function tests, blood glucose, hormone measurements, serum amylase;

- Family history of endocrine disorders, especially of the pituitary, parathyroids and pancreas.

The following Special stains and Immunostains are useful in the diagnosis of pancreatic lesions:

Congo red for amyloid ;

Immunohistochemistry :

- Cytokeratins to demonstrate inapparent infiltrating carcinoma cells in small biopsies and to distinguish undifferentiated carcinoma from lymphoma or sarcoma ;

- Neuroendocrine markers : Chromogranin, NSE ;

- Lymphoid markers :

- Hormones : Insulin, glucagons, gastrin, pancreatic polypeptide, VIP, ACTH.