Scenario: 2023
Patient diagnosed with single tumor Right UOQ Breast 1.9 cm DCIS & 2mm invasive lobular carcinoma
Question: How would you code histology?
- 8520/3 Lobular carcinoma, nos
- 8522/3 Infiltrating duct and lobular carcinoma
Answer: 8522/3 Infiltrating duct and lobular carcinoma
Rationale:
BREAST SOLID TUMOR RULES
- Multiple Primary Rules
- Rule M3 Abstract a single primaryi when there is a single tumor.
- Note 1: A single tumor is always a single primary.
- Note 2: The tumor may overlap onto or extend into adjacent/contiguous site or subsites/quadrants.
- Note 3: The tumor may have in situ and invasive components.
- Note 4: The tumor may have two or more histologic components.
- Histology Rules-Code the histology according to the rule that fits the case
- Different histologies
- Code the histology which comprises the majority of tumor.
- Note 1: This instruction does not apply to:
- Invasive carcinoma NST/ductal and lobular carcinoma (use the combination code 8522/3).
- Rule H8 Code the invasive histology when both invasive and in situ components are present (see Notes 2 and 3 for exceptions).
- Note 2: The following histologies are exceptions to this rule. When a single tumor has one of the histologies listed, continue through the rules.
- Encapsulated papillary carcinoma with invasion/with invasive carcinoma, NST/invasive duct carcinoma
- Solid papillary carcinoma with invasion
- Note 3: When a single tumor has carcinoma NST/duct and lobular with different behaviors, continue through the rules.
- Note 2: The following histologies are exceptions to this rule. When a single tumor has one of the histologies listed, continue through the rules.
- Different histologies
- Rule M3 Abstract a single primaryi when there is a single tumor.
- Rule H15 Code duct carcinoma and lobular carcinoma 8522/3 when the final diagnosis is any of the following:
-
- Invasive carcinoma NST/duct carcinoma and invasive lobular carcinoma (includes invasive pleomorphic lobular carcinoma)
- Intraductal and invasive lobular carcinoma (includes invasive pleomorphic lobular carcinoma)
- Infiltrating duct and lobular carcinoma in situ (LCIS)
- Infiltrating duct and pleomorphic lobular carcinoma in situ
- Infiltrating lobular carcinoma and ductal carcinoma in situ (DCIS)
- Infiltrating pleomorphic lobular carcinoma and ductal carcinoma in situ (DCIS)
- Note 1: Assign behavior code /3 even when an in situ histology is mixed with an invasive. This aligns with ICD-O-3.2 and was vetted with specialty matter experts.
- Note 2: CAP uses the term Invasive carcinoma with ductal and lobular features (“mixed type carcinoma”) as a synonym for duct carcinoma/carcinoma NST AND lobular carcinoma 8522/3.
- Note 3: Although the instructions in the “Coding Multiple Histologies in a Single Tumor” section state, “Code the histology that comprises the majority of tumor”, 8522/3 identifies both invasive carcinoma NST/duct carcinoma and invasive lobular carcinoma and is the most accurate description.
- And for those of you who are like, what??? When did that change, be sure to review the December 2022 Revision History for the Solid Tumor Rules
- Breast: Table 2: Histology Combination Codes
- Duct + Lobular row
- 8519 (Pleomorphic lobular carcinoma) added
- Note 1 deleted: Both histologies, duct and lobular, must have the same behavior code.
- “Additional Combinations of duct and lobular” section added