Breast dataset Flashcards
Solitary cyst
Benign
>10mm cyst lined by attenuated or apocrine type
If papillary growth it should go under papilloma or carcinoma
Fibrocystic change
Multiple cyst formation
Lined by apocrine epithelium, fibrosis, UEH and columnar change
Different to cystic change within other lesion
if hyperplasia present, it should be mentioned separately
Apocrine can only be atypical when nuclear size is greater than 3x
Columnar cell change without atypia
Spectrum of columnar cell hyperplasia to flat epithelial atypia and flat HG DCIS
Fibroadenoma
Two population
Connective tissue and epithelium - pericanalicular or intracanalicular growth pattern
mainly spindle cell but can have other mesenchymal pattern
Epithelium - bilayer, may have some changes - apocrine metaplasia, sclerosing adenosis, blunt duct adenosis, hyperplasia of usual type
May have atypia - usually lobular
Malignant cases stroma - sarcomatoid Cellular infiltrative Mitotic activity
Papilloma
Arborescent, fibrovascular stroma covered by inner myoepithelial and outer epithelial layer
can have associated UEP, Atypia and DCIS
Sclerosing adenosis
organoid lobular enlargement increased numbers of acinar structures exhibit elongation and distortion Epithelial component benign Can infiltrate connective tissue Calcification can be present Can get cancerisation
Sclerosing lesion - radial scar
Pseudoinfiltrative growth pattern Less than 10mm Tubular but not cellular Fibroelastosis random Positive for myoepithelial marker
Periductal mastitis/ductal ectasia
larger to intermediate size ducts in sub areolar location
Duct lined by normal/attenuated epithelium
Contain eosinophilic material
Inflammatory infiltrate with plasma cells
Duct ectasia vs cyst More round than elongated shape Tendency to cluster Lack of stromal elastin Frequent presence of apocrine metaplasia
Usual epithelial hyperplasia
mixed population of epithelial cells, myoepithelial cells mosaic pattern ER is heterogeneic positive Irregular slit like lumina Infrequent mitosis Streaming epithelial bridges Nuclear space uneven
Atypical ductal hyperplasia
Uniform cell population, merge with UEH within same duct space
MIxture of well delineated area and irregular slit like tubule
Rare necrosis
Nucleoli small
Negative CK5
Uniform ER
DCIS
Single unform cell population
Well developed micropapillary, cribriform or solid patterns
Well delinated regular pucnhed out lumina
Nuclear spacing even
Monotonous population
Nucleoli small
Can have different variant apocrine clear cell neuroendocrine signet ring
Columnar cell lesions types
Columnar cell change
Columnar cell hyperplasia
Flat epithelial atypia
Flat HG in situ carcinoma
Columnar cell change and hyperplasia
Lobular acini lined by epithelial cells that are tall and snouted in a manner similar
When it is piled up - hyerplasia
Often dilated tubule
Flat epithelial atypia
Cells amorphologically similar to ADH/DCIS
Round nuclei with clumped chromatin/vesicular nuclei
Mitosis are infrequent
Nuclear polarity disturbed
Atypical lobular hyperplasia/LCIS
Cytological features
Discohesive
Round, cuboidal, polygonal with clear cytoplasm
Nuclei with nucleoli
ALH - less than half TDLU
LCIS - more than half TDLU
Pleomorphic variant - grade 3
can have necrosis and calcification
Papillary carcinoma in situ
Encysted papillary carcinoma
No myoepithelial cells in the fibrovascular core
PCIS had myoepithelial cell at the duct
ECP Ca - no myoepithelial layer
Paget’s disease of the nipple
Adenocarcinoma cells within the epidermis of the nipple
Cam5.2 and Her2 +ve
Needs to r/o Melanoma, SCC
Invasive carcinoma
Pure - >90%
Mixed - 50-90%
NOS - <50%
Grade
Tubular formation - >75%, 10-75% and <10%
Cribriform count as tubules
Nuclear atypia - cell size, vesicular nuclei, nucleoli, shape variation
MItotic activity - (0.5mm FOV) <7, <14, >14
Grade 1 3-5
grade 2 6/7
grade 3 8/9
Invasive lobular carcinoma
intracytoplasmic lumina Alveolar variant exhibits small aggregates of >20 cells solid variant Tubulo-lobular - microtubule formation Pleomorphic "Single file"
Invasive tubular carcinoma
Round, ovoid, angulated tubules Cellular fibrous stroma DDx radial scar Infiltrate fat low grade by definition
Invasive micropapillary carcinoma
“up side down”
Aggregate of cuboidal to columnar neoplastic cells
Empty stromal space
Apical pole faces out
Metaplastic carcinoma
Heterogenous grousp with differentiation into squamous and mesenchymal lesion
Squamous cell - usuallly within cyst lining
fibromatosis like - spindle cell type with squamous cell, low mitotic activity
low grade adenosquamous
Spindle cell carcinoma - pleomorphic
