#1: Solid Tumor Rules (2018)
#2: Multiple primaries
Source 1: 2018 Solid Tumor Rules
Solid Tumor Rules/Multiple primaries--Breast: How many primaries should be abstracted when papillary carcinoma is identified in two biopsies and a subsequent lumpectomy identified invasive ductal carcinoma with multifocal ductal carcinoma in situ (DCIS)? See Discussion.
The right breast ultrasound shows a 1.4 cm mass at 8 o'clock and a separate mass .6 cm at 7 o'clock (site code for both C50.5). Pathology report: Right 8 o'clock core needle biopsy fragments of intracystic noninvasive papillary carcinoma (8504/2), right 7 o'clock core needle biopsy fragments of intracystic noninvasive papillary carcinoma (8504/2). Then, another facility performs a right breast lumpectomy (operative note not available). Outside Facility: Right breast lumpectomy pathology shows invasive ductal carcinoma .6cm (8500/3) multifocal DCIS .5cm greatest dimension tumor site right breast NOS.
Should we use Rule M12-Abstract multiple primaries when separate/non-contiguous tumors are on different rows in Table 3 in the Equivalent Terms and Definitions. Timing is irrelevant. Note: Each row in the table is a distinctly different histology. So would this be two primaries C50.5 (8504/2) and C50.9 (8500/3)?
Abstract as multiple primaries using Breast Solid Tumor Rule M12 as these are separate, non-contiguous tumors on different rows in Table 3.