Talk:Non-invasive breast carcinoma

DCIS & invasive

Microscopic

The specimen consists of incisional biopsies (x2) of the right breast that was submitted in two cassettes.

A. The sections show an invasive mammary carcinoma - nests of atypical epithelial cells (with mild nuclear enlargement and pleomorphism, moderate pale-gray cytoplasm, and very rare mitotic activity) within the breast stroma without a surrounding myoepithelial component and a desmoplastic stromal response. The maximal extent of the invasive component is 0.45 cm. There is minimal tubule formation (Nottingham tubule score 2-3/3), scant mitotic activity (Nottingham mitotic score 1/3) and mild nuclear pleomorphism (Nottingham nuclear score 1/3).

There are abundant nests of low grade ductal carcinoma in situ with a solid and cribriform architecture. Hemosiderin-laden macrophages are present. No calcifications are identified in the tumour, DCIS or benign breast parenchyma.

B. The sections show atypical epithelial cells (with mild nuclear enlargement and pleomorphism, moderate pale-gray cytoplasm) that, focally, that appear to bud into the breast stroma without a surrounding myoepithelial component. There are abundant nests of low grade ductal carcinoma in situ with a solid and cribriform architecture - the nests of cells have sharply demarcated/punched-out tubular structures, focally, that have atypical cells arranged around them. No slit-like structures are present. The cells within the nests have streaming focally. Hemosiderin-laden macrophages are present. No calcifications are identified in the DCIS or benign breast parenchyma.

Comment: The relevant findings agree with those of the primary pathologist. The mammographic abnormality should be completely excised.

Part B is felt to be primarily ductal carcinoma in situ (DCIS), that focally has some features of epithelial hyperplasia of the usual type (EHUT); specifically, there is cellular streaming. Features that favour DCIS are: (1) the lack of slit-like spaces, (2) the punched-out circular spaces with palisaded epithelial cells (“Roman bridges” appearance), and (3) the (focal) equal spacing of epithelial cells (“cookie cutter” appearance).

Final diagnosis

DIAGNOSIS: A. Right breast, incisional biopsy:
Invasive mammary carcinoma, Nottingham grade 1-2/3.
Extent of invasion at least 0.45 cm.
No lymphovascular invasion identified.

Ductal carcinoma in situ (cribriform and solid pattern), Grade 1/3.
No necrosis identified.

B. Right breast, incisional biopsy:
Suspicious for microinvasive mammary carcinoma.

Ductal carcinoma in situ (cribriform and solid pattern), Grade 1/3.
No necrosis identified.

DCIS in papillary lesion, DCIS

Microscopic

The specimen consists of left breast mastectomy and sentinel node excision, for a large complex partially cystic subareolar mass that distorts and elevates the nipple–areola complex.

Part A.
The sections show a circumscribed lesion with fibrovascular cores (papillary lesion). There is epithelial proliferation with cells that have moderate nuclear enlargement, irregular chromatin with focal clearing, and nucleoli (seen with the 10x objective). There is low mitotic activity (2 mitoses / 10 HPF, 1 HPF = 0.2376 mm^2). The epithelial cells have a cribriform architecture and focally form a sheet. There is no necrosis in the papillary lesion.

In the surround breast there are large atypical hypercellular glands with necrosis and atypical cohesive cells with nuclear atypia. The glands are well circumscribed and basal cells are discernible in many. No stromal desmoplasia is identified.

Three morphologically benign lymph nodes are present, in which no carcinoma was identified. There is cystic glandular dilation (fibrocystic change) and focal columnar cell morphology in the epithelial component without atypia and hyperplasia (columnar cell change).

Focally, the skin has a prominent granular layer and invaginates into a space containing abundant keratinous debris (block A). There is an intraductal paucicellular fibrotic mass composed of bland spindle cells (probable sclerosed papilloma).

Immunostaining with p63 and SMMS was done on several blocks and showed preservation of the myoepithelial layer.
Part B.
The sections show morphologically benign lymph nodes with a non-specific sinus histiocytosis. There is no macrophage nuclear enlargement. Emperipolesis is not identified. No tumour cells are identified. No morphologically concerning keratin staining cells were identified.

Final diagnosis

1. Left breast, mastectomy:
Papilloma with ductal carcinoma in situ, Architecture: cribiform and solid, Grade 2/3.
Ductal carcinoma in situ, Architecture: cribiform (with necrosis) and solid, Grade 3/3.
No invasive carcinoma is identified.
Three lymph nodes negative for malignancy (0 / 3).
Fibrocystic change.
Columnar cell change.
Epidermal inclusion cyst.
Sclerosed papilloma.

2. Sentinel node excision:
Seven lymph nodes negative for malignancy (0 / 7).

DCIS in papilloma

Microscopic

The specimen is a surgical biopsy for a right breast mass, that was previously biopsied.

The sections show an intraductal lesion with fibrovascular cores, epithelial proliferation and mild nuclear atypia. There is no necrosis and no mitotic figures are identified.

Two small foci of atypical, nested epithelial cells (~ 1 mm) are present at the edge of the lesion and adjacent to tissue with biopsy changes (cholesterol clefts, fibrosis, fat necrosis).

The surrounding breast has cystic glandular dilation with apocrine change, and fibroadenomatoid changes. There is also epithelial hyperplasia with cellular streaming, slit-like spaces in the gland periphery, and bland nuclei.

Evaluated with immunostains: Positive: ER strong-diffuse (nucleus), p63 strong (nuclear), SMMS (cytoplasmic). Negative: CK5/6.

Comment: The lesion represent a papilloma with low-grade DCIS and epithelial displacement in association with biopsy changes. The two foci of epithelial displacement morphologically resemble microinvasive carcinoma, which would be managed the same way.

Final diagnosis

Breast, right, surgical biopsy:
Papilloma with: (1) Ductal carcinoma in situ (DCIS) – solid pattern, grade 1/3, (2) Partial hyalinization, (3) Epithelial displacement / biopsy artifact, - lesion completely excised.
Surrounding breast: Focal fibroadenomatoid change, Florid epithelial hyperplasia, Fibrocystic changes with apocrine metaplasia.