Invasive ductal carcinoma

Author: Mikael Häggström

Gross examination

Gross appearance of invasive ductal carcinoma.

As per:

• Breast biopsy or excision

or mastectomy.

Microscopic evaluation

Invasive ductal carcinoma, with occasional entrapped normal ducts (arrow).

Differential diagnosis

In invasive ductal carcinoma, malignant cells have penetrated the basement membrane, in contrast to ductal carcinoma in situ.

Staging

Stage by the TNM system as follows in sections below.

Also, look for any angiolymphatic invasion. If present, check whether it reaches outside the tumor, and if so, how far. Give greatest dimension (,or 3 dimensions, generally by adding up the estimated thicknesses of involved slices)).

Primary Tumor (T) Tumor – Depends on the tumor at the primary site of origin, as follows: TX: inability to assess that site Tis: ductal carcinoma in situ (DCIS), lobular carcinoma in situ (LCIS) or Paget's disease of the breast Measurements can be made by marking the tumor on microscopy, and then measuring between the markings, which may overlap between multiple slides as shown. T1: Less than 2 cm T1a: 0.1 to 0.5 cm T1b: 0.5 to 1.0 cm T1c: 1.0 to 2.0 cm T2: 2 to 5 cm T3: Larger than 5 cm T4 T4a: Chest wall involvement T4b: Skin involvement T4c: Both 4a and 4b T4d: Inflammatory breast cancer, a clinical circumstance where typical skin changes involve at least a third of the breast. Regional Lymph Nodes (N) Lymph Node: The lymph node values depend on the number, size and location of breast cancer cell deposits in various regional lymph nodes, such as the armpit (axillary lymph nodes), the collar area (supraclavicular lymph nodes), and inside the chest (internal mammary lymph nodes.) Each stage is as follows: N0: There is some nuance to the official definitions for N0 disease, which includes: N0(i+) : Isolated Tumor Cell clusters (ITC), which are small clusters of cells not greater than 0.2 mm, or single tumor cells, or a cluster of fewer than 200 cells in a single histologic cross-section, whether detected by routine histology or immunohistochemistry; N0(mol-): regional lymph nodes have no metastases histologically, but have positive molecular findings (RT-PCR). N1: Mobile ipsilateral axillary nodes. Lymph node clusters 0.2 - 2.0 mm can be called "micrometastasis". At least one carcinoma focus over 2.0 mm is called "Lymph node metastasis". If one node qualifies as metastasis, count all other nodes even with smaller foci as metastases as well. Critical numbers of involved nodes: 1-3, 4-9, and 10 and over. Note any extranodal extension. N2: Fixed/matted ipsilateral axillary nodes. N3 N3a – Ipsilateral infraclavicular nodes N3b – Ipsilateral internal mammary nodes N3c – Ipsilateral supraclavicular nodes Distant Metastases (M) M0: No clinical or radiographic evidence of distant metastases M0(i+): Molecularly or microscopically detected tumor cells in circulating blood, bone marrow or non-regional nodal tissue, no larger than 0.2 mm, and without clinical or radiographic evidence or symptoms or signs of metastases, and which, perhaps counter-intuitively, does not change the stage grouping, as staging for in M0(i+) is done according to the T and N values M1: Distant detectable metastases as determined by classic clinical and radiographic means, and/or metastasis that are histologically larger than 0.2 mm. Overall stage A combination of T, N and M, as follows: Stage 0: Tis Stage I: T1N0 Stage II: T2N0, T3N0 T0N1, T1N1, or T2N1 Stage III: Invasion into skin and/or ribs, matted lymph nodes, T3N1, T0N2, T1N2, T2N2, T3N2, AnyT N3, T4 any N, locally advanced breast cancer Stage IV: M1, advanced breast cancer

Further information: Evaluation of tumors

Further information: Evaluation of tumors

Report

Breast excision

• Tumor size, if not already given from gross report. Give 3 dimensions or greatest dimension.
• Histopathologic subtype if apparent, but "invasive carcinoma" is acceptable.
• Stage
• Grade, preferably by overall BRE grade. Optionally, give scores for the components thereof.

• Extent of any angiolymphatic invasion.

• Margins of resection, as closest distance from carcinoma to margin in mm or cm or "tumor on ink"/"carcinoma is present on margin". ((If applicable, also specify as "close margins" (no tumor on ink but <2 mm), or "negative margins" (≥2 mm).))
• Results of any immunohistochemistry and other tests

• HER2 as a score or status.
• Ki-67, preferably as labeling index

Example:

Breast excision with 70 x 55 x 18 mm ductal invasive breast cancer. Nottingham grade II. Estrogen receptor positive, progesterone receptor negative, HER2 receptor score 0, Ki-67 index 17%, T1b. Radically removed.

Needle or core biopsy

• Histopathologic subtype if apparent, but "invasive carcinoma" is acceptable.
• Results of any immunohistochemistry and other tests, as per excision
• Presence of absence of lymphatic and/or vascular invasion
• Optionally: Provisional grading. Grading can alternatively be deferred to excision.
• State if studies are deferred for a later excision sample

For cancers, generally include a synoptic report, such as per College of American Pathologists (CAP) protocols at cap.org/protocols-and-guidelines.

synoptic report example

Tumor type:  invasive ductal carcinoma with micropapillary pattern

Tumor size:  greatest microscopic measurement of invasive carcinoma in positive core(s)):  0.7 cm

In-situ component: no

Microscopic grading (Nottingham modification of the Bloom-Richardson system):

• Only applies to infiltrating ductal and lobular carcinoma:  

Tubule formation: Little or none (score =3)

Nuclear pleomorphism: Marked variation in size, nucleoli, chromatin clumping, etc. (score =3)

Mitotic count : Less than 6 mitoses per 10 hpf (score =1)

Composite score: 7 points  (applies to infiltrating ductal and lobular carcinoma only)

Histologic grade: Grade II: 6-7  points

Nuclear grade: grade 3

Microcalcifications: Present in non-neoplastic tissue

Lymphocytic host response: absent

Necrosis:  absent

Blood vessel invasion: absent

Histopathology of lymphatic invasion by carcinoma, H&E stain

Lymphatic and/or vascular invasion: absent

Skin involvement: not applicable

Results of immunohistochemical stains for prognostic markers (as per original report):

Estrogen Receptor (ER) Status:  Positive (greater than 10% of cells demonstrate nuclear positivity)

Percentage of Cells with Nuclear Positivity:  91-100%

Average Intensity of Staining:  Strong

Progesterone Receptor (PgR) Status:  Positive

Percentage of Cells with Nuclear Positivity:  51-60%

Average Intensity of Staining:  Strong, moderate and weak

HER-2 by IHC:  2+ / Equivocal

REFLEX HER-2 FISH TEST:  Nonamplificed (ratio 1.5;  3.5 Her-2 signals/cell)

Ki-67:

Percentage of Cells with Nuclear Positivity: 43%

Primary Antibody: MIB1

Cold Ischemia and Fixation Times: 3 minutes

Fixation Time (hours): 14 hours and 33 minutes

Fixative:  formalin

Main page

• Main page of Patholines