Section V.3, Histology, Behavior, and Differentiation

V.3.4 Behavior

To code behavior, use the best information in the pathology report, regardless of whether it appears in the microscopic description, final diagnosis, or comments. If an AJCC staging form provides the best information, use it if the form is signed by a physician. ICD-O-3 assigns a behavior code as the fifth digit of the histology number, following the slash. (For example, in the number 8012/3 for large cell carcinoma, the 3 is the behavior code.) The codes are:

* Not reportable to the California Cancer Registry

** Reportable behavior, but enter code 3.

V.3.4.1 ICD-O-2/Pathology Conflicts.

If there is a conflict between the behavior code specified by ICD-O for a histologic subtype and the behavior described by a pathologist in the final diagnosis, the pathologic diagnosis generally prevails. ICD-O codes only indicate the usual behavior.

V.3.4.2 In Situ Coding.

The term "in situ" means a tumor that meets all microscopic criteria for malignancy, except invasion of basement membrane. (For further discussion of in situ, see Section V.5.8). Therefore, in situ behavior can be determined only by pathologic examination, and not by clinical evidence alone. If a tumor is classifiable as in situ according to the time period rules for stage at diagnosis (see Section V.5), code the lesion as in situ. In other words, a behavior code of 2, in situ, corresponds to a stage code of 0, in situ, and vice versa. Computer and visual edits will verify that the codes in these two fields correspond. Do not interpret terms like "approaching in situ" or "very close to in situ" as in situ. Reportable terms indicating in situ behavior include:

AIN III (anal intraepithelial neoplasia, Grade II-III or III)**

Bowen's Disease

DCIS (ductal carcinoma in situ)

DIN 3 (ductal intraepithelial neoplasia 3)**

Clark's level 1 for melanoma (limited to epithelium)

Confined to epithelium

Hutchinson's melanotic freckle

Intracystic, non-infiltrating

Intraductal

Intraepidermal

Intraepithelial

Intrasquamous

Involvement up to but not including the basement membrane

LCIS (lobular carcinoma in situ)

Lentigo maligna

LIN (laryngeal intraepithelial neoplasia)**

Lobular neoplasia, Grade III

No stromal invasion

Non-infiltrating

Non-invasive

Precancerous melanosis

Preinvasive

Queyrat's erythroplasia

Stage 0

VAIN III (vaginal intraepithelial neoplasia, Grade II-III or III)*

VIN III (vulvar intraepithelial neoplasia, Grade II-III or III)*

* Effective with cases diagnosed 1/1/1992 and later

** Effective with cases diagnosed 1/1/2001 and later

All other terms have been reportable since the region’s reference date.

As a reminder, carcinoma in situ (including squamous cell and adenocarcinoma) of the cervix and Cervical Intaepithelial Neoplasia, CIN III, are not reportable effective with cases diagnosed January 1, 1996 and later. Prostatic Intraepithelial Neoplasia (PIN III), morphology code 8148/2 is also not reportable to the CCR.

V.3.4.3 Microinvasion.

Code a pathologic diagnosis of "microinvasive"--meaning the earliest stage of invasion--as malignant, not in situ. For the diagnosis of microinvasive squamous cell carcinoma, a common form of cervical cancer, use the morphology code provided by ICD-O-3, 8076/3.

SEER Program Manual entry available

COC (FORDS manual) entry available

NAACCR Data Standards and Data Dictionary entry available