Pathology and staging of breast cancer

Pathology refers to the examination of tissue under a microscope to find out whether it’s cancerous or non-cancerous and to determine the type of tumour it is. Different types of tumours can affect the breast.

Breast calcifications

Calcifications are deposits of calcium in the breast tissue:

• macrocalcifications
• microcalcifications

Benign conditions and tumours

Benign conditions are changes to the breast tissues that are not related to cancer and are not usually life-threatening. Benign tumours are non-cancerous growths that do not spread to other parts of the body and are not usually life-threatening.

• benign conditions
  • atypical hyperplasia
  • breast pain (mastalgia)
  • breast cysts
  • fibroadenoma
  • fibrocystic breast changes
  • gynecomastia (breast enlargement in men)
  • mammary duct ectasia
  • nipple discharge
  • other benign conditions
    • radial scars
    • fat necrosis
    • adenosis
• benign tumours
  • intraductal papilloma
  • phylloides tumours
  • rare benign tumours
    • lipoma
    • hemangioma
    • hamartoma
    • adenoma
    • neurofibroma
    • granular cell tumour

Malignant tumours

Malignant tumours are cancerous growths that have the potential to metastasize (spread to other parts of the body):

• adenocarcinoma
  • ductal carcinoma in situ (DCIS)
  • lobular carcinoma in situ (LCIS)
  • invasive ductal carcinoma
  • invasive lobular carcinoma
• inflammatory breast cancer
• Paget disease of the nipple
• triple negative and basal-like breast cancers
• rare malignant tumours
  • non-Hodgkin lymphoma
  • sarcoma
    • angiosarcoma
    • rhabdomyosarcoma
    • dermatofibrosarcoma protuberans
  • carcinoma
    • adenoid cystic carcinoma
    • carcinosarcoma (metaplastic carcinoma)
    • adenosquamous carcinoma
  • melanoma
  • malignant phylloides tumour

Once the type of tumour has been diagnosed, the doctor will also consider:

• the grade of the tumour (how abnormal the cancer cells look and behave)
• the stage of the cancer, including if it has spread (metastasized) and where it has spread
• prognostic factors (special characteristics that might influence the course of the disease)
• survival statistics for the particular type and stage of cancer

All of this information helps the doctor to make a treatment plan.

See a list of questions to ask your doctor about pathology and staging.