World Health Organization classification of tumors of the breast
The World Health Organization classification of tumors of the breast is the most widely used pathologic classification system for such disorders. The current revision, part of the 4 edition of the WHO series, was published in 2012 and is reflected in the article below .
Classification
Epithelial tumors
Invasive breast carcinoma
- invasive breast carcinoma of no special type (NST)
- pleomorphic carcinoma
- carcinoma with osteoclast-like stromal giant cells
- carcinoma with choriocarcinomatous features
- carcinoma with melanotic features
- invasive lobular carcinoma
- classic lobular carcinoma
- solid lobular carcinoma
- alveolar lobular carcinoma
- pleomorphic lobular carcinoma
- tubulolobular carcinoma
- mixed lobular carcinoma
- tubular carcinoma
- cribriform carcinoma
- mucinous carcinoma
- carcinoma with medullary features
- medullary carcinoma
- atypical medullary carcinoma
- invasive carcinoma of no special type with medullary features
- carcinoma with apocrine differentiation
- carcinoma with signet-ring-cell differentiation
- invasive micropapillary carcinoma
- metaplastic carcinoma
- metaplastic carcinoma of no special type
- low-grade adenosquamous carcinoma
- fibromatosis-like metaplastic carcinoma
- squamous cell carcinoma
- spindle cell carcinoma
- metaplastic carcinoma with mesenchymal differentiation
- chondroid differentiation
- osseous differentiation
- other types of mesenchymal differentiation
- mixed metaplastic carcinoma
- myoepithelial carcinoma
- rare types
- carcinoma with neuroendocrine features
- neuroendocrine tumor, well-differentiated
- neuroendocrine carcinoma, poorly differentiated (small cell carcinoma)
- carcinoma with neuroendocrine differentiation
- secretory carcinoma
- invasive papillary carcinoma
- acinic cell carcinoma
- mucoepidermoid carcinoma
- polymorphous carcinoma
- oncocytic carcinoma
- lipid-rich carcinoma
- glycogen-rich clear cell carcinoma
- sebaceous carcinoma
- salivary gland/skin adnexal type tumors
- cylindroma
- clear cell hidradenoma
- carcinoma with neuroendocrine features
Epithelial-myoepithelial tumors
- pleomorphic adenoma
- adenomyoepithelioma
- adenomyoepithelioma with carcinoma
- adenoid cystic carcinoma
Precursor lesions
- ductal carcinoma in situ
- lobular neoplasia
- lobular carcinoma in situ
- classic lobular carcinoma in situ
- pleomorphic lobular carcinoma in situ
- atypical lobular hyperplasia
- lobular carcinoma in situ
Intraductal proliferative lesions
- usual ductal hyperplasia
- columnar cell lesions including flat epithelial atypia
- atypical ductal hyperplasia
Papillary lesions
- intraductal papilloma
- intraductal papilloma with atypical hyperplasia
- intraductal papilloma with ductal carcinoma in situ
- intraductal papilloma with lobular carcinoma in situ
- intraductal papillary carcinoma
- encapsulated papillary carcinoma
- encapsulated papillary carcinoma with invasion
- solid papillary carcinoma
- in situ
- invasive
Benign epithelial proliferations
- sclerosing adenosis
- apocrine adenosis
- microglandular adenosis
- radial scar/complex sclerosing lesion
- adenomas
- tubular adenoma
- lactating adenoma
- apocrine adenoma
- ductal adenoma
Mesenchymal tumors
- nodular fasciitis
- myofibroblastoma
- desmoid-type fibromatosis
- inflammatory myofibroblastic tumor
- benign vascular lesions
- hemangioma
- angiomatosis
- atypical vascular lesions
- pseudoangiomatous stromal hyperplasia
- granular cell tumor
- benign peripheral nerve-sheath tumors
- lipoma
- liposarcoma
- angiosarcoma
- rhabdomyosarcoma
- osteosarcoma
- leiomyoma
- leiomyosarcoma
Fibroepithelial tumors
- fibroadenoma
- phyllodes tumor
- benign
- borderline
- malignant
- periductal stromal tumor, low grade
- hamartoma
Tumors of the nipple
Malignant lymphoma
- diffuse large B-cell lymphoma
- Burkitt lymphoma
- T-cell lymphoma
- anaplastic large cell lymphoma, ALK-negative
- extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue type
- follicular lymphoma
Metastatic tumors
Tumors of the male breast
- gynecomastia
- carcinoma
- invasive carcinoma
- in situ carcinoma
Clinical patterns
See also
- breast neoplasms (overview)
- breast lymphoma
