Question: 20190056




#1:   Behavior
#2:   Breast


Source 1:   ICD-O-3
Source 2:   WHO Class Breast Tumors
Notes:   4th Edition


Behavior--Breast: What is the behavior of a solid papillary carcinoma when a pathologist does not indicate it in the pathology report and follow-up with the pathologist to obtain clarification regarding the behavior is not possible?  See Discussion.


Example: Mastectomy specimen final diagnosis shows two foci of invasive ductal carcinoma including: Invasive ductal carcinoma, no special type, in association with solid papillary carcinoma (tumor #1, 1 cm, slices 6 and 7) and invasive ductal carcinoma, no special type (tumor #2, 1.2 cm, slices 9 and 10).

Summary Staging outlines, Tumor #1: Histologic Type: Invasive ductal carcinoma, no special type, in association with solid papillary carcinoma. As well as, Tumor #2: Histologic type: Invasive ductal carcinoma, no special type. Additional findings include ductal carcinoma in situ (DCIS): presently approximately 3.3 cm, spanning slices 10-13.

The behavior of the solid papillary carcinoma component will affect the provisional histology of the first tumor (8523/3) per Rule H17 vs. 8500/3 per Rule H7). Based on the response, we can determine whether this represents a single or multiple primaries (single primary per M13 vs. multiple primaries per M14).


Review all sections of the pathology report carefully for any mention of invasion, or lack of invasion, pertaining to the solid papillary carcinoma.

Per WHO 4th Ed Breast: If there is uncertainty that there is invasion, these lesions should be regarded as in situ. The distinction between in situ and invasive disease in solid papillary carcinoma is difficult. 


Last Updated


Date Finalized