Histologic Types of Solcia et al for Pancreatic Endocrine Tumors

 

Parameters:

(1) tumor size (diameter in centimeters)

(2) mitotic rate in 10 high power fields (HPF)

(3) percentage of cells Ki-67 positive

 

Diameter in cm	Mitotic Rate	Ki-67 Positivity	Histologic Type
< 0.5 cm	< 2 per 10 HPF	< 2%	microadenoma
0.5 - 2.0 cm	< 2 per 10 HPF	< 2%	macroadenoma
> 2.0 cm	<= 3 per 10 HPF	1 - 5%	borderline tumor
> 3.0 cm	1 - 10 per 10 HPF	1 - 10%	low-grade carcinoma
NA	> 10 per 10 HPF	> 10%	undifferentiated, small cell carcinoma

 

where:

• The size of a tumor is important for adenomas, but probably not for borderline tumor or low-grade carcinoma.

• The table may not cover all possible combinations.

• A tumor > 2 cm in diameter with 1-3 mitoses and 1-5% Ki-67 positivity is either a borderline tumor or a low-grade carcinoma.

• A tumor with > 10 mitoses per 10 HPF but Ki-67 <= 10% is probably a small cell carcinoma. A tumor with <= 10 mitoses per HPF and Ki-67 positivity > 10% is harder to classify.

• I could not find the area of the microscopic field used.

 

Additional criteria for malignancy:

(1) gross invasion of adjacent organs

(2) metastases to regional lymph nodes, liver or distant sites

(3) blood vessel invasion

 

Adenomas are often asymptomatic, although macroadenomas may be functional.

 

Borderline tumors and low grade carcinomas may be asymptomatic, functional or have signs of a slow growing tumor.

 

Small cell carcinomas are often rapidly progressive without hormone production, but may be functional or associated with a paraneoplastic syndrome.