Morphology & Grade

ICD-O-3 Morphology Codes

For diagnostic terms in the pathology report which are not part of the following list, refer to your ICD-O-3 manual.

Adenocarcinoma (ICD-O-3 code 81403)

  • Ductal (850_3) most common--70-80% of cases; also called duct carcinoma, duct cell carcinoma)
  • Medullary (851_3)
  • Mucinous or colloid (848_3)
  • Lobular (852__) frequently bilateral at diagnosis)
  • Tubular (82113)
  • Papillary (805__)
  • Ductular (85213) a histologic type distinct from ductal carcinoma)

Common combination morphologies

  • 8522/3 Infiltrating duct and lobular carcinoma (C50._)
    lobular and ductal carcinoma (C50._)
    • Infiltrating duct and lobular carcinoma in situ (C50._)
    • Intraductal and lobular carcinoma (C50._)
    • Infiltrating lobular carcinoma and ductal carcinoma in situ (C50._)
  • 8523/3 Infiltrating duct mixed with other types of carcinoma (C50._)
    • Infiltrating duct and cribriform carcinoma (C50._)
    • Infiltrating duct and mucinous carcinoma (C50._)
    • Infiltrating duct and tubular carcinoma (C50._)
    • Infiltrating duct and colloid carcinoma (C50._)
  • 8524/3 Infiltrating lobular mixed with other types of carcinoma (C50._)
    • Infiltrating lobular mixed with cribriform carcinoma (C50._)
    • Infiltrating lobular mixed with mucinous carcinoma (C50._)
    • Infiltrating lobular mixed with tubular carcinoma (C50._)
    • Infiltrating lobular mixed with colloid carcinoma (C50._)

Behavior types

Invasive (infiltrating)
In situ (15-20% of all breast cancers)

Synonyms for carcinoma in situ: noninfiltrating, intraductal, lobular carcinoma in situ, Stage 0, noninvasive, no stromal involvement, papillary intraductal, papillary non infiltrating, intracystic, lobular neoplasia, lobular noninfiltrating, confined to epithelium, intraepithelial, intraepidermal

Other morphologic terms: Paget disease (854_3)—crusty tumor of nipple and areola, which may be associated with underlying tumor of the ducts.

Inflammatory carcinoma (85303)—frequently involves entire breast and is characterized by reddened skin and edema caused by tumor spread to lymphatic channels of skin of breast, usually without an underlying palpable mass. Inflammatory carcinoma is a clinical diagnosis verified by biopsy of the tumor and overlying skin. Key words: lymphatic involvement of skin, peau d'orange, orange-peel skin, en cuirasse

Cystosarcoma phyllodes (90203)—a variant of mammary fibroadenoma; locally aggressive; rarely metastasizes

Bloom-Richardson grading system—Synonyms: Modified Bloom-Richardson (BR), Scarff-Bloom-Richardson (SBR), SBR Grading, BR Grading, Elston-Ellis modification of Bloom-Richardson grading system. The Bloom-Richardson grading scheme is a semi-quantitative grading method based on three morphologic features of invasive (no-special-type) breast cancers. The morphologic features are:

  1. degree of tumor tubule formation
  2. tumor mitotic activity
  3. nuclear pleomorphism of tumor cells (nuclear grade)

Seven possible scores are condensed into three BR grades. The three grades then translate into well-differentiated (BR low grade), moderately differentiated (BR intermediate grade) and poorly differentiated (BR high grade).

combined scores
Differentiation/BR Grade ICD-O-3
6th digit
3, 4, 5 Well-differentiated
(BR low grade)
6, 7 Moderately differentiated
(BR intermediate grade)
8, 9 Poorly differentiated
(BR high grade)