Breast lumps overview

# Overview
Breast lumps are considered as one of the prevalent symptoms among women. Breast lumps can be found by individuals or clinical breast examination. Although, breast lumps are often determined as benign masses, they could be the first common presentation of breast cancer and require more clinical and imaging studies and medical interventions. Benign breast disease includes wide range of lesions which originate from either mammary epithelium or other mammary tissues. Breast lumps may be related to vascular, inflammatory or traumatic pathologies. Breast lumps are usually palpable, nodular masses and could be associated with or without particular characteristics. Breast lumps could also be found in children, adolescents and hopefully they are considered as benign tumors.The first step for evaluation of breast lumps is clinical examination then if examination was suspicious later imaging studies such as mammography, ultrasound or magnetic resonance imaging are required for further evaluation. Breast lumps management depends on disease pattern, available facilities and specialist.

# Historical Perspective
Throughout the history many women experienced breast diseases but there were not any courage to express their problem to the public. In 1970s, all women with malignant breast lumps underwent radical mastectomy rather than performing previous biopsies. Although fine needle aspiration biopsy was introduce in 1930, it was used for breast lumps in 1950s. Breast ultrasound was used in 1950s and mammography was found in 1975 to diagnose early stages of breast cancers.

# Classification
Breast lumps may be classified according to epithelial hyperplasia into 3 subtypes: non-proliferative, proliferative disease and proliferative disease without atypia. Breast lumps may be classified into 3 sub-types based on histological regions: lobular region, ductal region, different origins.

# Pathophysiology
Breast development is influenced by different hormones such as estrogen, progesterone, prolactin, and estradiol. The pathophysiology of breast lumps depends on the histological subtypes. Histological findings of breast lumps are different from each other which lead to diagnosis. It is thought that breast lumps are the result of hormonal events and genetic mutations. Estrogen and progesterone may increase risk of benign proliferative disease to 74% and benign breast lesion in post-menopausal women receiving estrogen with or without progesteron for more than 8 years raise by 1.7 fold. Gene mutations are classified into 3 categories based on cancer risk such as BRCA1, BRCA2, TP53 considered as high risk mutations, Homozygous ataxia-telangiectasia, somatic mutation in CHEK2, BRIP1, PALB2  moderate risk mutations, and low risk genes mutation are not determined yet.

# Causes
Breast lumps causes can be classified to various groups according to gender and age. Causes of female breast mass could be  cancer, inflammatory, infectious, hormonal imbalance, trauma. Male breast enlargement identified as gynecomastia. Causes of gynecomastia may be multifactorial, hormonal imbalance, genetic factors, endocrine factors.Breast lumps may develop among children and adolescents, however, there are probably benign ones and related to peripubertal and pubertal phases.

# Differentiating Breast lumps from Other Diseases
Breast lumps must be differentiated from other diseases such as malignancy, cysts, inflammation and non-inflammatory solid lumps. Breast symptoms such as nipple discharge and mastalgia require assessment as well. Differentiating different types of breast lumps are based on imaging findings and breast clinical exam results.

# Epidemiology and Demographics
The incidence rate of breast lumps is not particularly clear due to the fact that breast lumps is not considered as a life threatening condition and majority of the women who receives medical therapies or surgeries come into account.The prevalence of benign breast disease is approximately 68% among all breast diseases and the incidence of breast diseases is higher on the left upper/outer quadrant of breast. Fibrocystic diseases are more frequent in age of 40-44 years and fibroadenoma is more frequent between 15-35 years. Fibroadenoma rate is higher in black women. African-American women have worse prognosis and higher mortality rate in comparison European American women.

# Risk Factors
Risk factors of breast lumps are generally age (higher cancer risk while aging), past history of breast disease or biopsy, positive familial history in first-degree relatives, genetic mutations such as BRCA1 and BRCA2, endogenous hormonal exposure such as age at menarch, first pregnancy, menopause, breast feeding, and parity, exogenous hormonal exposure such as usage of contraceptive pills and hormonal replacement therapy, and lifestyle factors such as alcohol consumption, inactivity, obesity, and previous history of radiation exposure.

# Screening
Screening for breast lumps is recommended by breast examination, ultrasound, mammography, magnetic resonance imaging.

# Natural History, Complications, and Prognosis
If benign breast lumps left untreated, those proved to be benign both by clinical examination and cytological diagnosis, do not become malignant and 68% of benign breast lumps resolve by time mostly after 2 years. Benign breast lumps should approved to be benign both clinically and cytologicaly. Because some of breast lumps which thought to be benign ones can turn to be malignant by cytological results. Breast lumps which approved to be benign both clinically and cytologicaly in women under 35 years can resolve over time if do not excised.

# Diagnosis

## Diagnostic Study of Choice
Mammography is the gold standard test for the diagnosis of breast lumps in women aged >40 years old. Ultrasound is the gold standard test for the diagnosis of breast lumps in women aged  40 or age  40 years. In women aged > 40 years; no further evaluation is needed in case of clearly benign mass in mammography; however, ultrasound imaging is required for the rest of the findings mammography. Approach to breast lumps in women >40 years is depended on breast imaging reporting and data systems (BI-RADS) stages. Medical therapy of breast lumps in women< 40 years is depended on ultrasound results and BI-RADS categories.

## History and Symptoms
The important key to breast lumps diagnosis is history and physical exams. History must be complete and include all details regarding to age, parity, pregnancy, past history of breast diseases, familial history, and drug history. Common symptoms of breast lumps include breast pain, palpable mass, nipple discharge, galactorrhea.

## Physical Examination
Physical examination of patients with breast lumps should perform both in sitting position and supine position to examine  all 4 quadrants of breast. Careful physical examination may lead to diagnosis. Breast physical exam should include information about, number, size, location, shape, mobility, consistancy of masses, nipple discharge, and axillary lymph nodes.

## Laboratory Findings
There are no diagnostic laboratory findings associated with breast lumps.

## Electrocardiogram
There are no ECG findings associated with breast lumps.

## X-ray
There are no x-ray findings associated with breast lumps.

## Ultrasound
Breast ultrasound is the first imaging modality in patients with palpable masses under age 40 years old and is adjunctive modality to mammography for patients older than 40 years. Breast sonography is a type of imaging used to confirm abnormal findings on mammography or MRI. Breast ultrasound improves breast cancer detection rate.

## CT scan
There are no CT scan findings associated with breast lumps.

## MRI
MRI is considered as the primary imaging modality in selected patients and may be used when results of other imaging modalities are indeterminate. Breast MRI has some indications and does not use regularly. Breast MRI is not the primary modality for diagnosis of breast lumps and does not provide any additional findings to ultrasound and mammographic results and has both false-positive and false-negetive results.

## Other Imaging Findings
Mammography is considered as the first and mainstay for evaluation of palpable masses in women over the age of 40 years. Diagnostic mammogram contains particular views by focal compression of specific part of breast tissue.There is standard method for reporting mammographic findings which is called breast imaging reporting and database system (BI-RADS) which is classified into 7 categories.

## Other Diagnostic Studies
The only certain method to approve the presence of breast malignancy is breast lump biopsy.The three types of biopsies are core-needle biopsy, open surgical biopsy, and fine needle biopsy. Core-needle biopsy has different types such as ultrasound guided-core needle biopsy, stereotactic-guided core-needle biopsy, MRI-guided core-needle biopsy, and freehand core-needle biopsy. Core-needle biopsy has high sensitivity and specificity. Triple test score is used by surgeons for assessment of palpable breast lumps. Classic type of triple test includes clinical breast examination, FNA, and mammography and modified version includes clinical breast examination, core-needle biopsy and ultrasound.

# Treatment

## Medical Therapy
There is no specific medical therapy for breast lump. However, there are certain medications that may be used prophylactically to reduce the risk of transformation of breast lump into breast carcinoma.

## Surgery
Surgical management of breast lumps depends on the type of masses based on core-needle biopsy. Atypical ductal hyperplasia, atypical lobular hyperplasia, lobular neoplasia, lobular carcinoma in situ, flat epithelial atypia. Multiple, peripheral and atypic papillomas, large sclerosing adenosis and radical scar >10mm, atypic and enlargic fibroadenomas, desmoid tumor, mammary fibromatosis, phyllodes tumor, symptomatic and large pseudoangiomatous stromal hyperplasia requires surgical consultation and excision. The rest of breast lumps require observation and follow-up. The final decision for excisional biopsy is based on recommendations from pathologist, radiologist, and surgeons.

## Primary Prevention
There are no established measures for the primary prevention of breast lumps.

## Secondary Prevention
Secondary prevention of breast lumps consists of modifiable risk factors and preventive factors to decrease the rates of breast cancer. The protective factors include controlling alcohol consumption, weight control, physical activity, healthy diet, breast feeding, prophylactic bilateral oophorectomy for BRCA1 and BRCA2 carriers, hormonal replacement therapy avoidance, and use of tamoxifen for high risk women aged > 35 years. In order to reduce breast cancer recurrence, surveillance and follow-up by either physical examination and mammography are required.