New WHO Classification of Breast Tumors

  I. Epithelial tumors
  1 Infiltrative ductal carcinoma (non-specific)
  1.1 Mixed type carcinoma
  1.2 Polymorphic carcinoma
  1.3 Carcinoma with osteoblastic giant cells
  1.4 Carcinoma with choriocarcinoma features
  1.5 Carcinoma with melanotic features
  2 Infiltrating lobular carcinoma
  3 Small tubular carcinoma
  4 Infiltrating sieve carcinoma
  5 Medullary carcinoma
  6 Mucin producing carcinoma
  6.1 Mucinous carcinoma
  6.2 Cystic adenocarcinoma and columnar cell mucinous carcinoma
  6.3 Indolent cell carcinoma
  7 Neuroendocrine tumors
  7.1 Solid neuroendocrine carcinoma
  7.2 Atypical carcinoid tumors
  7.3 Small cell/oat cell carcinoma
  7.4 Large cell neuroendocrine carcinoma
  8 Infiltrating papillary carcinoma
  9 Infiltrating micropapillary carcinoma
  10 Large sweat cell carcinoma
  11 Carcinoma of chemosis
  11.1 Pure epithelial carcinoma
  Squamous cell carcinoma
  Adenocarcinoma with spindle cell metaplasia
  Adenosquamous carcinoma
  Mucinous epidermoid carcinoma
  11.2 Mixed epithelial/mesenchymal metaplastic carcinoma
  12 Lipid-rich carcinoma
  13 Secretory carcinoma
  14 Eosinophilic carcinoma
  15 Adenoid cystic carcinoma
  16 Alveolar cell carcinoma
  17 Glycogen-rich clear cell carcinoma
  18 Sebaceous gland carcinoma
  19 Inflammatory carcinoma
  20 Lobular neoplasia
  20.1 Lobular carcinoma in situ
  21 Intraductal proliferative lesions
  21.1 Common ductal hyperplasia
  21.2 Flat epithelial atypical hyperplasia
  21.3 Atypical ductal hyperplasia
  21.4 Ductal carcinoma in situ
  22 Microinvasive carcinoma
  23 Intraductal papillary tumors
  23.1 Central papillary tumor
  23.2 Peripheral papilloma
  23.3 Atypical papilloma
  23.4 Intraductal papillary carcinoma
  23.5 Intracapsular papillary carcinoma
  24 Benign epithelial hyperplasia
  24.1 Adenopathy and its subtypes
  Sclerosing adenopathy
  Sweat gland adenopathy
  Blind duct adenopathy
  microglandular adenopathy
  adenomyelinating adenopathy
  24.2 Radiation scarring/complex sclerosing lesions
  24.3 Adenomas
  Tubular adenoma
  Lactating adenoma
  Sweat adenoma
  Polymorphic adenoma
  Ductal adenoma
  II. Myoepithelial lesions
  1 Myoepithelial hyperplasia
  2 Myoepithelial adenopathy
  3 Adenomyositic epithelial tumor
  4 Malignant myoepithelial tumor
  Mesenchymal tumors
  1 Hemangioma
  2 Angiomatosis
  3 Perivascular cell tumor
  4 Pseudoangioma-like mesenchymal hyperplasia
  5 Myofibroblastoma
  6 Fibromatosis (aggressive)
  7 Inflammatory myofibroblastoma
  8 Lipomas
  8.1 Angiomyolipoma
  9 Granulosa cell tumor
  10 Neurofibroma
  11 Schwann cell tumor (nerve sheath tumor)
  12 Angiosarcoma
  13 Liposarcoma
  14 Rhabdomyosarcoma
  15 Osteosarcoma
  16 Smooth muscle tumor
  17 Smooth muscle sarcoma
  Fibroepithelial tumors
  1 Fibroadenoma
  2 Foliar tumor
  2.1 Benign
  2.2 Cross-border
  2.3 Malignant
  3 Periductal mesenchymal sarcoma, low grade
  4 Malformation tumor of the breast
  V. Nipple tumor
  1 Papillary adenoma
  2 Sweat duct-like adenoma
  3 Paget’s disease of the nipple
  Malignant lymphoma
  1 Diffuse large B-cell lymphoma
  2 Burkitt’s lymphoma
  3 MALT-type B-cell lymphoma in the extra-nodal marginal zone
  4 Follicular lymphoma
  Metastatic tumors
  Male breast tumor
  1 Male mammary gland development
  2 Carcinoma
  2.1 Infiltrative carcinoma
  2.2 Carcinoma in situ