Pancreas
General
Frozen section
Authors: Hulya Sahin Ozkan, M.D., Olca Basturk, M.D.
Editorial Board Members: Wei Chen, M.D., Ph.D., Xiaoyan Liao, M.D., Ph.D.
Last author update: 13 April 2023
Last staff update: 17 April 2024
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PubMed Search: Frozen section pancreas
Table of Contents
Definition / general | Procedure | Tips | Frozen section images | Additional references | Board review style question #1 | Board review style answer #1Cite this page: Sahin Ozkan H, Basturk O. Frozen section. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/pancreasfrozensection.html. Accessed December 26th, 2024.
Definition / general
- Click here for the frozen section procedure topic
- This topic describes frozen section (intraoperative consultation) procedures for pancreaticoduodenectomy and distal pancreatectomy specimens
- Essential clinical history: none
Procedure
- Frozen section for primary diagnosis:
- Preoperative diagnostic modalities have mostly replaced frozen section practice for primary diagnosis
- However, it is still performed on occasional cases when the preoperative cytology or biopsy was inconclusive or when there are unusual intraoperative findings (Arch Pathol Lab Med 2022;146:84)
- Frozen section for distant metastasis:
- Since presence of any distant metastasis means unresectable disease for pancreatic ductal adenocarcinoma (PDAC) cases, surgeons may send suspected tissues (e.g., liver, peritoneum, distant lymph nodes, etc.) for frozen section examination
- If it reveals metastasis, the procedure will most likely be aborted (J Clin Pathol 2007;60:975)
- Frozen section for margin status:
- Main purpose for this request is to evaluate the completeness of the resection (Ann Surg Oncol 2013;20:3626)
- If the margin (i.e., pancreatic parenchyma / duct, biliary duct) is positive, the surgeon will resect additional tissue to achieve a clear margin
- For the pathologist, the main question is whether there is an invasive carcinoma or high grade dysplasia in the margin or not
- Presence of low grade dysplasia does not require further resection
- Frozen section for intraductal neoplasms:
- Sometimes surgeons may request intraoperative examination of an intraductal neoplasm to investigate if there is high grade dysplasia or invasive carcinoma
- However, both high grade dysplasia and invasive carcinoma are usually focal and an invasive carcinoma component may not be easy to identify grossly
- Therefore, it is not possible to fully exclude high grade dysplasia or invasive carcinoma during the frozen section and a discrepancy may occur between frozen section and permanent assessment (Ann Surg 2016;263:162)
Tips
- It can be challenging to differentiate pancreatic ductal adenocarcinoma from PanIN or a reactive process (e.g., chronic pancreatitis) in frozen section
- Findings in favor of pancreatic ductal adenocarcinoma include:
- Loss of normal lobular organization and haphazardly distributed ducts / glands (Semin Diagn Pathol 2004;21:268)
- Irregular shaped ducts with angular contours and incomplete lumen formation (Arch Pathol Lab Med 2002;126:1169, Semin Diagn Pathol 2004;21:268)
- Complex and atypical arrangement (e.g., cribriform, cord-like or single cell infiltration) (Arch Pathol Lab Med 2002;126:1169)
- Abnormal location of glands (i.e., adjacent to a thick walled, medium - small sized muscular artery) (Am J Surg Pathol 2004;28:613)
- Naked (solitary) duct in adipose tissue without an intervening stroma (Semin Diagn Pathol 2004;21:268)
- Perineural or vascular invasion
- Nuclear atypia, pleomorphism (i.e., variation in nuclear size of 4:1 or more within an individual gland), hyperchromatism, nuclear membrane irregularities, nuclear grooves, raisinoid / wrinkled nuclei (especially in the foamy gland pattern), mitotic figures, atypical mitosis, loss of polarity and large nucleoli (Arch Pathol Lab Med 2002;126:1169, Semin Diagn Pathol 2004;21:268)
- Cytoplasmic characteristics (e.g., foamy gland pattern pancreatic ductal adenocarcinoma is characterized by abundant foamy / microvesicular cytoplasm) (Am J Surg Pathol 2000;24:493)
- Intraluminal necrotic / cellular debris and plugs (Arch Pathol Lab Med 2002;126:1169, Semin Diagn Pathol 2004;21:268)
- Disorganized, basophilic and even myxoid stroma (Semin Diagn Pathol 2004;21:268)
- Sometimes, low grade gastric-like mucinous epithelium may be identified in the pancreatic parenchyma margin
- For such cases, it is difficult (if not impossible) and unnecessary to distinguish pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN) during the intraoperative consultation
- It is sufficient to document that there is no high grade dysplasia or invasive carcinoma in the margin; low grade mucinous epithelium is identified in the margin and differential diagnoses include low grade PanIN and low grade IPMN (Ann Surg Oncol 2013;20:3626)
Frozen section images
Contributed by Hulya Sahin Ozkan, M.D.
Cytological features of PDAC
Perineural invasion
Foamy gland pattern PDAC
Liver metastasis of PDAC
Lymph node metastasis of PDAC
Potential mimicker of PDAC
Additional references
Board review style question #1
Which of the following is a typical reason for frozen section requests in the surgical management of pancreatic tumors?
- To evaluate a suspicious liver lesion
- To evaluate extranodal tumor extension in a metastatic peripancreatic lymph node
- To evaluate neoadjuvant treatment response
- To evaluate the histologic grade of the tumor
- To evaluate the mitotic index of the tumor
Board review style answer #1
