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SEER Inquiry System - Report
Produced: 09/11/2025 2:03 AM
Question 20150019
Inquiry Details
References:
WHO Class Endocrine Tumors
Question:
Reportability/Histology--Pancreas: Is well-differentiated neuroendocrine tumor (M8240/3) as stated on a pathology report reportable or can the clinical information be used as an adjunct to the path report, which further states the specific type of neuroendocrine tumor is an Insulinoma, therefore, NOT reportable (M8151/0)? See discussion.
Discussion:
The diagnosis date is 2/24/14. The pathology report of the pancreas shows: Well-differentiated neuroendocrine tumor (NET), low grade (WHO G1 of 3). Addendum: Ki-67 confirms low grade of pancreatic endocrine tumor (less than 2% Ki-67/MIB-1 index). Chromogranin confirms the endocrine nature of the tumor. The Pre and Post Op Diagnosis is pancreatic neuroendocrine tumor consistent with insulinoma. AJCC Stage as noted on path report: pT1, pNX, pM.
The physician states: The patient has a well-documented insulinoma. Biochemistries confirmed the disease and it is localized in the tail of the pancreas.
The issue with NETs is that pathology report reflects what is seen or what is quantified under the microscope; often, there is a specimen without the accompanying medical history and clinical signs. Many of these NETs are specified on the basis of the hormone, as usually measured in the blood, that is overproduced, something not seen microscopically. All of the islet cell tumors are NETs. The insulinoma in the example above is a well-differentiated NET that is causing insulin to be over-produced. Thus, the diagnoses are not discordant; insulinoma is a more specific NET.
Answer:
When the pathology diagnosis is a neuroendocrine tumor (/3) and the clinical diagnosis is an insulinoma (/0), report the case. Although ICD-O-3 classifies insulinoma as /0, the most recent WHO classification lists it as /3. The pathologist and physicians for this case are likely guided by the WHO classification and as a result, would view both the NET diagnosis and the insulinoma diagnosis as malignant. You could report this case as 8240/3 or 8151/3.
