Medullary breast carcinoma is a rare type of

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...

that is characterized as a relatively

circumscribed In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius. Not every polyg ...

tumor with pushing, rather than infiltrating, margins. It is histologically characterized as poorly differentiated cells with abundant cytoplasm and pleomorphic high grade vesicular nuclei. It involves

lymphocytic A lymphocyte is a type of white blood cell (leukocyte) in the immune system of gnathostomata, most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated immunity, cell-mediated, cytotoxicity, cytotoxic innate imm ...

(a type of

white blood cell White blood cells, also called leukocytes or leucocytes, are the cell (biology), cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders. All white blood cells are produced and de ...

) infiltration in and around the

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

and can appear to be brown in appearance with necrosis and hemorrhage. Prognosis is measured through staging but can often be treated successfully and has a better prognosis than other infiltrating breast carcinomas. Medullary breast carcinoma is one of five types of epithelial breast cancer: ductal, lobular, medullary, colloid, and tubular. Very rare cases of it have been diagnosed in men (see

male breast cancer Male breast cancer (MBC) is a cancer in males that originates in their breasts. Males account for less than 1% of new breast cancers with about 20,000 new cases being diagnosed worldwide every year. Its incidence rates in males vs. females are, ...

Ductal Carcinoma in situ Ductal carcinoma in situ (DCIS), also known as intraductal carcinoma, is a pre-cancerous or non-invasive cancerous lesion of the breast. DCIS is classified as Stage 0. It rarely produces symptoms or a breast lump one can feel, typically being d ...

(DCIS) is less commonly present, and medullary breast cancer presents as a soft, fleshy mass with a pushing border. Tumors commonly possess mutations of

E-cadherin Cadherin-1 or Epithelial cadherin (E-cadherin), (not to be confused with the APC/C activator protein CDH1) is a protein that in humans is encoded by the ''CDH1'' gene. Mutations are correlated with gastric, breast, colorectal, thyroid, and ovarian ...

, which results in its overexpression. Strengthened adhesions between tumor cells reduce the frequency of metastasis.

Epidemiology

It tends to occur more often in younger women and is more frequently found in those with

BRCA1 Breast cancer type 1 susceptibility protein is a protein that in humans is encoded by the ''BRCA1'' () gene. Orthologs are common in other vertebrate species, whereas invertebrate genomes may encode a more distantly related gene. ''BRCA1'' is a h ...

gene mutations. Although this breast carcinoma is more frequently found in BRCA 1 gene mutations, most individuals with BRCA 1 gene mutations do not have medullary breast carcinoma. Medullary breast carcinoma is rare and can be seen in about less than 5% of invasive breast cancers. Due to the complicated nature of classification, there are difficulties in subtyping this type of breast cancer.

Diagnosis

Histopathology of medullary breast carcinoma

Criteria must be met through the Ridolfi criteria. Although there are other classifications for diagnosis, the Ridolfi criteria are the most commonly used. There must be histologic evidence of lymphoplasmacytic infiltration, noninvasive microscopic circumscription, greater than 75% syncytial growth pattern, and high-grade nuclei. It is immunologically typically triple-negative, with negative estrogen receptors (ER), negative progesterone receptors (PR), and negative

HER2/neu Receptor tyrosine-protein kinase erbB-2 is a protein that in humans is encoded by the ''ERBB2'' gene. ERBB is abbreviated from erythroblastic oncogene B, a gene originally isolated from the avian genome. The human protein is also frequently refer ...

receptors. There are also medullary breast carcinomas that are found to be estrogen receptors (ER) and/or progesterone receptor (PR) positive, making diagnosis less straightforward.

Staging

TNM Staging The TNM Classification of Malignant Tumors (TNM) is a globally recognised standard for classifying the extent of spread of cancer. It is a classification system of the anatomical extent of tumor cancers. It has gained wide international acceptance ...

is used to determine the extent of the disease and is used to guide the management and treatment of the cancer. It can be divided into Primary Tumor (T), Lymph Nodes (N), and Metastasis (M). The American Joint Committee on Cancer (AJCC) revised the staging system in 2018 to include the anatomic extent of the disease as well as prognostic biomarkers.

Prognostic biomarkers

* Estrogen receptor (ER), Progesterone receptor (PR), and

HER2 receptor Receptor tyrosine-protein kinase erbB-2 is a protein that in humans is encoded by the ''ERBB2'' gene. ERBB is abbreviated from erythroblastic oncogene B, a gene originally isolated from the avian genome. The human protein is also frequently refer ...

expression * Histologic grade: Determined through the characteristics and features of tumor * Recurrence score: Score <11 shows better prognosis

Management and treatment

Imaging

If breast cancer is suspected, imaging should be obtained through ultrasound, mammography, and/or MRI with appropriate biopsies.

Immunohistochemical testing

Immunological and histological testing should also be obtained for receptor status, which influences the type of treatment required. Since medullary breast carcinoma typically presents as triple negative, it may be treated with a more intensive chemotherapy regimen as with other triple negative breast cancers. This cancer has been found to respond well to chemotherapy compared to other breast cancers. Despite this, some cases of medullary breast carcinoma do not require chemotherapy for successful treatment. Depending on immunologic status, endocrine therapy can be utilized as well.

Prognosis

Medullary breast carcinoma has a lower propensity to metastasize compared to other types of breast cancers. Compared to infiltrating ductal carcinomas, medullary breast carcinoma has a better prognosis and a significantly higher survival rate. The best measure of prognosis is through staging and axillary

lymph node A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that inclu ...

involvement in the absence of metastatic disease. The higher the involvement of

lymph nodes A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that includ ...

, the worse the prognosis. There is also an association between higher survival rates and chemotherapy response with the presence of lymphocytic infiltration.

References

External links

Medullary breast carcinoma
entry in the public domain NCI Dictionary of Cancer Terms {{DEFAULTSORT:Medullary Carcinoma Of The Breast Breast cancer