The mammary glands
develop in close association with a depot of adipose tissue that is commonly
referred to as the mammary fat pad.
The mammary fat pad is a matrix of adipose
and connective tissue capable of mediating hormone action and synthesizing an
array of growth regulatory molecules.
Mammography is a dedicated radiographic technique for imaging the breast.
Types of mammography
In general terms, there are two types of mammography: screening and diagnostic.
Mammography differs significantly in many respects from the rest of diagnostic imaging.
There are numerous mammography views that can broadly be split into two groups
supplementary views - additional information or problem solving
Standard views are bilateral craniocaudal (CC) and mediolateral oblique (MLO) views, which comprise routine screening ...
Mastitis refers to inflammation of the breast parenchyma, of which there are a number of subtypes:
puerperal mastitis: occurs usually from infection with Staphylococcus during lactation
non-puerperal mastitis: not related to lactation, and occurs usually in older women
Medical devices in the thorax are regularly observed by radiologists when reviewing radiographs and CTs.
tubing, clamps, syringes lying on or under the patient
rubber sheets, foam mattresses, clothing, hair braids, nipple piercings etc. may also be visible
The mediolateral oblique (MLO) view is one of standard mammographic views. It is the most important projection as it allows to depict most breast tissue.
The representation of the pectoral muscle on the MLO view is a key component in assessing the adequacy of patient positioning and ...
The mediolateral (ML) view is a supplementary mammographic view and shows less breast tissue and pectoral muscle than the mediolateral oblique view (MLO view).
The tube is rotated 90 degrees and the lateral aspect of the chest wall is along the bucky edge. The height is at the level ...
Medullary carcinoma of the breast (MCB) is an uncommon subtype of breast cancer and accounts for ~5% 1,4 of all breast cancers.
They tend to occur more frequently in younger women than other breast cancer types 7. The mean age of presentation varies from 46-54 years but in 10% of ...
Metachronous breast cancers are two breast cancers that occur in either breast in two different time periods.
Treatment and prognosis
The survival rate of women with metachronous breast cancers diagnosed within 2 years of the original primary is worse than those with unilateral disease 4.
Metaplastic breast carcinoma (MBC), also known as spindle cell carcinoma of the breast (SpCC), is a rare form of primary breast malignancy and accounts < 5% of breast carcinomas.
These are scarce lesions, rarely seen in general radiology practice. The lesions usually present as a mass in postme...
Metastases to the breast from non-mammary primary tumours are uncommon and account for 0.5-2.0% of all breast malignancies.
Metastases do not tend to cause retraction of the skin or nipple. Metastatic lesions are much more likely to be multiple or bilateral than primary ...
Metastatic axillary lymphadenopathy of unknown primary can be a very chellanging situation.
Usual potential sites include:
occult breast cancer: the incidence of an axillary lymph node manifestation from an occult primary breast cancer is low, ranging from 0.3-0.8% of all patients ...
A metastatic intramammary lymph node refers to an intramammary lymph node involved with metastatic or malignant disease.
Sonographic features that suggest metastatic involvement include 4:
disappearance or loss of central echogenic hilar region
Microglandular adenosis (MGA) of the breast is a pathological subtype of mammary adenosis. It is benign breast condition although can mimic a breast cancer (particularly tubular breast carcinoma 3,5) both clinically, radiology and pathologically.
It is considered the only benign brea...
A milk fistula is a situation where a fistulous connection develops between there skin and the lactiferous ducts. It is rare but potential complication if a core biopsy or excision biopsy of the breast is performed in a lactating patient.
The term milk of calcium (MOC) is given to dependent, sedimented calcification within a cystic structure or hollow organ. This sort of colloidal calcium suspension layering can occur in various regions:
renal: milk of calcium in renal cyst (most common)
breast: milk of calcium in breast cyst
Milk of calcium within a breast cyst is a mammographic feature observed when there is dependent calcium layering within breast cysts. It is typically observed as "tea cup" or "crescent shaped" calcifications on a true lateral (LM or ML) view on occasionally on a MLO view. On a CC view, these cal...
Mondor disease is a rare benign breast condition characterised by thrombophlebitis of the subcutaneous veins of the breast and anterior chest wall.
Although Mondor disease is rarely reported in the literature, this is likely in part due to lack of awareness of the entity. It tends...
Montgomery glands are large sebaceous glands in the breast, representing a transition between a mammary gland and a sweat gland.
Located within the nipple-areolar complex, Montgomery glands open onto the skin surface via protrusions on the skin known as Montgomery tubercles. They...
Montgomery tubercles are the openings of Montgomery glands on the skin surface.
They are about 1-2 mm papules on the skin surface located on the skin of the nipple and areola.
These tubercles become prominent during stimulation and pregnancy
They are named after Wi...
Mucinous carcinoma of the breast, also known as colloid breast carcinoma, is a subtype of invasive ductal carcinoma (IDC). They account for about ~ 2% (range 1-7% 4) of breast cancers.
It tends to occur in older women where a prevalence of as much as 7% is found among women 75 ye...
A multicentric breast cancer is a term given to a breast cancer where there are two or more breast cancers separated by normal breast tissue (often taken as 5 cm of separation 4). It is related to but distinct from the term multifocal breast cancer.
At a pathological level It can also mean 2
Multifocal breast cancer refers to two or more individual breast cancers diagnosed at the same time within the same quadrant of the same breast 1.
Breast manifestations of neurofibromatosis type 1 (NF1), or von Recklinghausen disease, it is characterised by multiple subcutaneous neurofibromas affecting the breast.
For a general discussion of the underlying condition, please refer to the article on neurofibromatosis type 1.
Nevoid hyperkeratosis of the nipple and the areola (NHNA) is a rare, idiopathic and benign dermatological condition.
Most often seen in females of reproductive age, especially during 2nd and 3rd decades of life. Less than 70 cases have been reported till now.
Nipple adenoma is a rare, benign breast lesion which often mimics a malignancy
Patient presents with bloody discharge from an ulcerated and painful nipple in one breast. There is itching associated with this lesion. Symptoms may show variation with the menstrual cycle. T...
During the 6th week of gestation, a pair of longitudinal thickening of the epidermis develop on the ventral surface of the embryo, extending from the axilla to the medial thigh, called "mammary ridges" (or "mammary line", “milk lines"). In large part these milk lines later atrophy, leaving only...
Nipple inversion is an important finding on mammography and correlation with patient history is essential. When nipple abnormalities such as inversion are identified, it is important for the technologist to document them in the medical record / mammography worksheet so that the radiologist will ...
Nipple markers can be a useful technique in the evaluation of densities overlying the expected position of the nipple on a chest radiograph. Not uncommonly a small round opacity projects over the lower thorax on a chest radiograph (see: solitary pulmonary nodule).
Often, especially in women, th...
Non-comedo type ductal carcinoma in situ is a subgroup of ductal carcinoma in situ (DCIS). This group comprises of relatively less aggressive types with low nuclear grade. It has multiple patterns which are often mixed:
cribriform type non-comedo DCIS
micropapillary type non-comedo DCIS
With increasing use of screening mammography and ultrasound for various indications, a large number of non-palpable breast lesions are being detected.
Among this large number of non-palpable masses, not all are malignant. The incidence of malignancy among these non-palpable lesions varies betwe...
This article lists examples of normal imaging of the breast and surrounding structures, divided by region and modality.
MLO and CC (standard mammographic views)
lateral: example needed
compression: example needed
cleavage view: example
axillary lymph n...
The Nottingham classification is used at the end of work up of a breast lesion to help guide management.
A = malignant
lesion needs surgical excision regardless of biopsy result
B = indeterminate
will accept a benign biopsy result, but only if it is congruent with imaging, i.e. a well circum...
Oil cysts in breast imaging refer to benign breast lesions where an area of focal fat necrosis becomes walled off by fibrous tissue.
Occurs across all age and ethnic groups with a female predilection. Usually associated with blunt trauma, if present in males.
Paget disease of the breast, which is also known as Paget disease of the nipple, has traditionally been described as a form of breast malignancy characterised by infiltration of the nipple epidermis by malignant cells. Although most cases have underlying focus or foci of in situ or invasive carc...
Paget disease can refer to either:
Paget disease of bone
Paget disease of breast
History and etymology
Both conditions are named after Sir James Paget (1814-1899) 1, British surgeon and pathologist.
Papillary carcinoma of the breast is a rare ductal breast malignancy.
They are thought to account for 1-2% of breast carcinomas 2. They typically present in postmenopausal patients with the mean age at being ~63-67 years.
A papillary carcinoma may manifest ...
Papillary lesions of the breast comprise a wide group and range from benign to malignant.
They develop as tufts of epithelium with a ﬁbrovascular core that arborize into branching papillae and protrude into the duct lumen.
papilloma of breast / intraductal papilloma of the b...
Mammographic density is considered a risk factor for breast cancer, and parenchymal patterns in breast imaging are important in the way in which the effects mammographic screening sensitivity. Women with high-risk density patterns should be screened more frequently and/or with additional views p...
The pectoralis major muscle is a muscle of the pectoral region, overlying the anterior chest wall but is considered an upper limb muscle due to its function.
sternal part: sternum and superior six costal cartilages
clavicular part: medial half of the clavicle
Perforating branches of the internal thoracic arteries arise from the paired internal thoracic arteries (also known as internal mammary arteries) and run in the superior six intercostal spaces. These arteries pierce the internal intercostal muscles and pectoralis major, contributing to the blood...
PGMI (Perfect, Good, Moderate, Inadequate) is a method of evaluation of clinical image quality in mammography developed by the United Kingdom Mammography Trainers Group with the support of the Royal College of Radiographers, aimed to ensure the maintenance of a high standard of mammography in Br...
Phyllodes tumour, also known as cystosarcoma phyllodes, is a rare fibroepithelial tumour of the breast which has some resemblance to a fibroadenoma. It is typically a large, fast growing mass that forms from the periductal stroma of the breast.
Phyllodes tumours account for less t...
Plasma cell mastitis is a benign breast condition which represents calcification of inspissated secretions in or immediately adjacent to ectatic benign ducts.
It is typically seen in older women (e.g. >60 years of age).
It is thought to represent aseptic inflammation ...
Poland syndrome refers to a congenital unilateral absence of the pectoralis major and minor muscles and is a recognised cause of unilateral hyperlucent hemithorax.
Poland syndrome is usually sporadic, although rare familial cases have been described 1. It is rare, with an estimat...
Popcorn calcification refers to amorphous calcifications often with rings and arcs that resemble popped corn kernels. This type of calcification may be seen in many radiological settings including 1:
chondroid lesions (e.g. enchondroma, chondrosarcoma)
Popcorn calcification in the breast is the classical description for the calcification seen in involuting fibroadenomas which, as the name suggests, has a popcorn-like appearance.
A fibroadenoma in the long run may degenerate and calcify. Initially there are a few punctate periphera...
The posterior nipple line (PNL) refers to a line drawn posteriorly and perpendicularly from the nipple towards the pectoral muscle (or the posterior image edge in CC) on the mammograms. In an adequately positioned breast, the measurement difference of this line between a CC view and MLO view sho...
Post surgical breast scar is a benign complication that usually occurs following surgical intervention to breast tissue. It can however be a strong and potentially very confusing mimicker of breast malignancy.
Review of the patient's past history and previous mammography...
Pregnancy associated breast cancer (PABC) is usually defined as a breast breast cancer diagnosed during pregnancy or one year following delivery. PABC occurs in one out of every 1500-10,000 pregnancies 5-6 and represents up to 3% of all breast malignancies. The incidence may be increasing due to...
Primary breast chondrosarcoma is a rare type of sarcoma that originates from the mammary stroma and not from the underlying bone or cartilage of the chest wall.
The prevalence of primary breast chondrosarcoma is reported to be 0.5-1%, they represent <5% of all sarcomas 1,14.
Primary osteosarcoma of the breast is an uncommon breast malignancy and is a sub type extraskeletal osteosarcoma.
While it can present in a wide are group, the peak age at presentation is around the 6th decade 7.
The presence of bone in breast lesions is not diagnosti...
Pseudoangiomatous stromal hyperplasia (PASH) is a benign, relatively uncommon form of stromal (mesenchymal) overgrowth within breast tissue that derives from a possible hormonal aetiology.
Typically affects women of reproductive age. It rarely affects males.
Pseudocalcifications and artifacts in the breast include
gold deposits in lymph nodes from intramuscular gold therapy for rheumatoid arthritis
They should be differentiated from parenchymal calcification. Precautions to be taken are t...
Pseudogynaecomastia refers to breast enlargement in men primarily due to fatty tissue but with no associated glandular or stromal tissue.
Puerperal mastitis refers to mastitis occurring during pregnancy and lactation.
It occurs most often during breast feeding and is rarely encountered during pregnancy.
The source of infection is the nursing infants nose and throat; the organisms being Staphylococcus aur...
Punctate microcalcifications in the breast are defined as calcific opacities <0.5 mm in diameter seen within the acini of a terminal duct lobular unit.
rarely in DCIS: punctate, clustered, segmentally distributed
Radial scar, or complex sclerosing lesion, is a rosette-like proliferative breast lesion. It is not related to surgical scarring. Some authors, however, reserve the latter term to lesions over 1 cm 5.
It is an idiopathic process with sclerosing ductal hyperplasia.
Its significance is that it...
work in progress - Fran/Derek
UK interpretation/system to guide investigation (2008)
The term recurrent breast cancer in medical imaging is given to recurrence of malignancy within the same breast at or close to the resection bed more than two years following surgical excision.
The rate of local recurrence may be as high as 19% in 10 years. The maximum for recurre...
A residual breast cancer is a remaining portion of the original primary breast cancer after an incomplete resection or following radiotherapy or chemotherapy. The term is particularly used in assessing patients who have had neo-adjuvant chemo +/- radiotherapy.
The reversed CC view is an additional view. It is useful for the study of breasts with surgical scars in the lower quadrants. The ability to see the scar through the compressor paddle offers to the mammographer the possibility to flatten it properly, reducing the formation of scar folds as well ...
Given that the rolled projections can be performed from any standard projection, the most commonly used is certainly the cranio-caudal one.
A rolled CC view It's performed to locate a lesion only visible in the cranio-caudal view, or when overlapped tissues in the standard view can simulate or...
Salad oil sign, also referred to as the droplet sign, is characterised by small rounded high T2 signal foci within a breast implant on MRI studies and represents water droplets or small amounts of gas within the silicone. It also can be characterised as hypointense foci on the water-suppressed s...
Sappey plexus is a network of lymphatics in the areola of the nipple. Sappey plexus assumes considerable importance in the identification of the sentinel lymph node since the subareolar way would be the most convenient for its simplicity to be injected and the most suitable in special cases, suc...
Scirrhous carcinoma of the breast is a pathological subtype of breast cancer. It is a subtype of invasive ductal carcinoma not otherwise specified and presents as a hard lump. The proportion of pathologic lymph node metastasis among scirrhous carcinomas is significantly higher than that among ca...
Sclerosing adenosis (SA) is a benign proliferative condition of the terminal duct lobular units characterised by an increased number of acini and their glands. It manifests as multiple small, firm, tender nodules, fibrous tissue, and variable microcysts within the breast. It is sometimes placed ...
Sclerosing lobular hyperplasia (SLH) of the breast, also known as fibro-adenomatoid mastopathy, is an uncommon benign proliferative breast lesion.
It tends to occur more often in adolescent and young adult patients (peak age in the thirties). In the United States, there may be a g...
Sclerosing papillomas of the breast are a sub type of intraductal papilloma of breast. It is termed when a papillary lesion form well-defined solid masses with a dominant sclerosed architecture 2. It is usually a histological diagnosis and usually cannot be differentiated from a non sclerosing p...
There are few areas in imaging specifically and in medicine in general, fraught with more controversy than screening for breast cancer. Due to the emotive issues surrounding the diagnosis, the scientific literature on breast screening and its issues reaches the lay press quickly and is sometimes...
Seromas are collections of serous fluid that usually occur as a complication of surgery, but can also be seen post-trauma. They are commonly seen as an early complication of breast surgery, where a potential space is left.
Seromas are distinct from haematoma as they contain almost ...
Silicone injection into various parts of the body has been used in many countries to achieve what are perceived to be cosmetic improvements. Most common sites for such injections are the breasts, face, and buttocks, although anywhere can be targeted.
This article is a general discussion of the...
Breast cysts are a relatively common cause of a breast lump in perimenopausal women, and usually causing wage pain or discomfort and slightly tender on palpation. They are a benign (BIRADS II) entity.
Breast cysts are caused by blockage of the terminal acini with resultant dilatation...
Skin calcifications in the breast usually form in dermal sweat glands after low grade folliculitis and inspissation of sebaceous material. Calcifications may also form in moles and other skin lesions. Often, these calcifications are in groups as they extend into small glands in the skin. Occasi...
The presence of skin thickening on mammography is variably defined, usually being more than 2mm in thickness. It can result from a number of both benign and malignant causes. They include:
inflammatory breast cancer: one of the most concerning causes of skin thickening: this usually ...
Snowstorm sign may refer to:
snowstorm sign: complete hydatiform mole (ultrasound)
snowstorm sign: extracapsular breast implant rupture (ultrasound)
snowstorm sign: thyroid pulmonary metastases (chest radiograph)
Snowstorm sign on breast ultrasound imaging represents the presence of free silicone droplets mixed with breast tissue giving a characteristic heterogeneous echogenic appearance with the dispersion of the ultrasound beam. It is considered the most reliable sign of extracapsular breast implant ru...
Spence tail is the prolongation of upper outer quadrant of the breast in the axillary direction. It is also called the axillary tail, once it passes through the foramen of Langer, it pierces the axillary fascia. The duct system is seen to extend into the axilla.
If this direct continuity with t...
Spontaneous nipple discharge in a non lactating breast can result from many causes which include:
papillary lesions of breast: present in ~35-50% of cases with spontaneous nipple discharge
ductal carcinoma in situ: 5-21%
A spot view (also known as a spot compression view or focal compression view) is an additional view performed by applying the compression to a smaller area of tissue using a small compression paddle, increasing the effective pressure on that spot. This results in better tissue separation and all...
Steatocystoma multiplex is a rare familial hamartomatous malformation that is characterised by the presence of multiple intradermal cysts, and can result in abnormal breast examinations.
They usually appear during adolescence and progress with age.
A handy mnemonic to recall the causes of a stellate breast lesion is:
S: summation shadow
T: tumour (i.e. invasive breast cancer)
R: radial scar
F: fibroadenoma / fat necrosis
A: adenosis (sclerosing)
CE: other causes, haematoma (e.g. postoperative, post bio...
Step-and-shoot is a technology of image acquisition in digital breast tomosynthesis characterised by stop scanning at every single angle during images acquisition.
Step-and-shoot technology allows advantages in microcalcifications conspicuity, spatial resolution, signal-to-noise Ratio improveme...
Stepladder sign may refer to:
intracapsular breast implant rupture (ultrasound)
gas-fluid levels in obstructed small bowel (erect abdominal radiograph)
The stepladder sign is a sonographic sign indicating an intracapsular breast implant rupture. It is considered the most reliable ultrasonographic finding in silicone gel breast implant intracapsular rupture. It is identified as multiple, discontinuous, parallel, linear echoes in the lumen, and i...
Step-oblique mammography is an accurate technique for determining whether a mammographic finding visible on multiple images on only one projection (but not elucidated using standard additional mammographic projections) represents a summation artefact or a true mass and for precisely localizing t...
Breast biopsy is performed whenever it becomes necessary to characterise a breast lesion. This consists of the withdrawal and collection of cells (cytologic exam) or tissue fragments (histologic exam) and in the anatomical-pathological analysis of the sample tissue.
There are many different wa...
Stereotactic mammotome is method of biopsing breast lesions, particularly if they are occult on ultrasound.
A vacuum-assisted core biopsy (VACB)-stereotactic breast biopsy is performed as a diagnostic approach when mammography shows irregularities with micro-calcifications, parenchymal distorti...
The sternalis muscle is an uncommon anatomic variant of the chest wall musculature and is of uncertain aetiology and function. Its importance lies in that it should not be mistaken for a pathological lesion.
Cadaveric studies have shown that the muscle is present in ~5% (range 1-...
Stewart-Treves syndrome refers to an angiosarcoma seen in the setting of lymphoedema 1.
It was classically attributed to lymphoedemas induced by radical mastectomy to treat breast cancer. Nowadays, we know that it can arise in any chronically lymphoedematous region due to any cause2.
Subareolar breast abscess are relatively uncommon and tend to occur mostly in young women.
Mastalgia, signs of inflammation, lump formation in the subareolar region and nipple discharge. In chronic cases fistula formation and nipple deformity may be seen.
The subcapsular line sign is a small localised leak from a silicone implant that leads to the formation of a thin layer of silicone between the implant shell and the fibrous capsule. It represents a minimally collapsed intracapsular breast implant rupture. It is best appreciated by MRI.
Supernumerary nipples are a common minor congenital malformation that consists of accessory nipples.
Supernumerary nipples are located along the embryonic milk lines. Ectopic supernumerary nipples are found beyond the embryonic milk lines. In human beings, the embryonic milk line extends from a...