What are the other Names for this Condition? (Also known as/Synonyms)

• ALH of Breast
• Mammary ALH
• Mammary Atypical Lobular Hyperplasia

What is Atypical Lobular Hyperplasia of Breast? (Definition/Background Information)

• Atypical Lobular Hyperplasia (ALH) of Breast is an atypical condition of the breast that is usually diagnosed under the microscope by a pathologist. It may be described as an atypical non-invasive neoplasm of the terminal duct lobules of breast. ALH is considered a precancerous condition. In other words, ALH of Breast is not cancer, but increases the risk for cancer
• Atypical Lobular Hyperplasia of Breast is usually diagnosed incidentally on breast biopsies undertaken for other abnormalities in the breast. Normally, ALH does not cause a mass lesion in the breast. Therefore, in vast majority of cases, it cannot be detected during routine mammogram screenings. Rarely, though, this condition may be associated with abnormal calcifications on mammograms
• There are no specific signs and symptoms of Atypical Lobular Hyperplasia of Breast too, either on breast examination or radiological imaging studies of the breast. However, in individuals diagnosed with this condition in the past, there is a slight increase in overall risk for breast cancer in the future. Thus, regular breast exams and appropriate vigilance are always necessary
• Atypical Lobular Hyperplasia of Breast is generally seen in middle-aged and older women. Currently, there are no well-characterized or specific predisposing factors for the development of ALH of Breast. Researchers believe that the cause of this abnormality may be associated with genetic factors
• A complete excision of the lesion may be recommended on a case by case basis, according to the evaluation of the healthcare provider. The prognosis of Atypical Lobular Hyperplasia of Breast on its surgical removal is generally excellent

Who gets Atypical Lobular Hyperplasia of Breast? (Age and Sex Distribution)

• Atypical Lobular Hyperplasia of Breast is generally observed in young, middle-aged, and older women (mean age of diagnosis is 50 years)
• The condition can affect individuals of all races and ethnic backgrounds
• Since the condition is an incidental diagnosis, the true prevalence of ALH of Breast is unknown
• It is reported that approximately 2% of reduction mammoplasty procedures may show atypical lobular hyperplasias

What are the Risk Factors for Atypical Lobular Hyperplasia of Breast? (Predisposing Factors)

The risk factors for Atypical Lobular Hyperplasia of Breast are not specifically known.

• However, women who have dense breast (breast density seen on a mammogram) report a higher incidence of the condition
• Some researchers believe that the risk factors for Atypical Lobular Hyperplasia of Breast are similar to those for other benign breast conditions. Such risk factors include:
  • Hormonal replacement therapy
  • Family history of breast cancer
  • Smoking
  • Alcohol over-consumption
  • Being overweight

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Atypical Lobular Hyperplasia of Breast? (Etiology)

The exact cause of development of Atypical Lobular Hyperplasia of Breast is presently not well-understood. However, several genetic and chromosomal alterations documented through molecular studies include:

• E-cadherin inactivation, which is an important step in the development of atypical lobular hyperplasia (ALH)
• Loss of heterozygosity (LOH) on 11q13 in ALH gene: Chromosomal material loss on 7p, 16p, 16q, 17p, and 22q and gains on 2p and 6q are reported in ALH
• CDH1 mutations are present in 81% of the cases

What are the Signs and Symptoms of Atypical Lobular Hyperplasia of Breast?

Most cases of Atypical Lobular Hyperplasia (ALH) of Breast may not exhibit any signs and symptoms. Many are unaware that they have the condition until they receive the pathology report on a breast biopsy. 

• ALH can involve multiple locations within the same breast, also known as multicentric atypical lobular hyperplasia
• It can involve one or both breasts (unilateral and bilateral atypical lobular hyperplasia)
• The condition is generally painless; very rarely, pain may be noted
• It may be associated with calcifications in some individuals on screening mammograms

How is Atypical Lobular Hyperplasia of Breast Diagnosed?

Atypical Lobular Hyperplasia of Breast may be diagnosed in the following manner:

• Complete physical examination with comprehensive medical and family history evaluation
• Breast exam to check for any lumps or unusual signs in the breasts
• Mammogram: A mammogram uses X-rays to provide images of the breast. The condition does not usually cause abnormal features on mammograms; however, in some cases, it may be associated with calcifications prompting a biopsy
• Breast ultrasound scan: Using high-frequency sound waves to produce images of the breast. Abnormal areas can be detected via an ultrasound study
• Computerized tomography (CT) or magnetic resonance imaging (MRI) scan of the breast
• Breast biopsy: Such abnormalities are often biopsied either through core biopsies of breast or breast lumpectomies
  • A biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
  • Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
  • Sometimes, the pathologist may perform additional studies, which may include immunohistochemical stains and molecular studies to assist in the diagnosis

Biopsies are the only methods used to determine whether an abnormality is benign or cancerous. These are performed by inserting a needle into a breast mass and removing cells or tissues, for further examination. There are different types of biopsies:

• Fine needle aspiration biopsy (FNAB) of breast mass: In this method, a very thin needle is used to remove a small amount of tissue
• Core needle biopsy of breast mass: A wider needle is used to withdraw a small cylinder of tissue from an abnormal area of the breast
• Open tissue biopsy of breast mass: A surgical procedure used less often than needle biopsies, it is used to remove a part or all of a breast lump for analysis

Even though several genetic abnormalities may be present, molecular studies, such as comparative genomic hybridization, are not required to make a diagnosis of the condition.

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Atypical Lobular Hyperplasia of Breast?

There may not be any significant complications of Atypical Lobular Hyperplasia of Breast.

• The condition is associated with an increased risk for subsequent breast cancer - the absolute risk of developing breast cancer in individuals diagnosed with atypical lobular hyperplasia is about 1% a year, with a cumulative risk of over 30% in 25 years
• The risk may be slightly higher for individuals who have a positive family history of breast cancer

How is Atypical Lobular Hyperplasia of Breast Treated?

• The treatment for Atypical Lobular Hyperplasia of Breast may involve surgery
  • The tumor may be removed during the diagnostic breast biopsy, or
  • It may be surgically removed via lumpectomy procedure
• Follow-up care with regular breast self-examinations and screening mammograms (lifelong) may be recommended by the healthcare provider

How can Atypical Lobular Hyperplasia of Breast be Prevented?

Currently, no specific preventive measures are available to prevent Atypical Lobular Hyperplasia of Breast. In general, it is important to be aware of the following:

• Regularly conduct breast self-exams to ensure that no lumps are present
• Maintain a healthy body weight and exercise regularly
• Implement and follow a well-balanced diet; a high intake of fiber via fresh fruits and vegetables helps in a healthy lifestyle
• Avoid or completely stop smoking
• If taking alcohol, only drink in moderation; limit to one or (maximum) two drinks a day
• Limit combination hormone therapy used to treat symptoms of menopause. It is advised that individuals be aware of the potential benefits and risks of such hormonal medications

What is the Prognosis of Atypical Lobular Hyperplasia of Breast? (Outcomes/Resolutions)

The prognosis of Atypical Lobular Hyperplasia of Breast is generally excellent on its surgical removal. However, close clinical monitoring is essential for long duration due to the risk for subsequent development of breast cancer.

The incidence of finding a malignant breast condition later in life when diagnosed with atypical lobular hyperplasia is increased in the following cases:

• Younger age at the time of diagnosis
• Individuals with a positive family history of the condition
• Presence of macrocalcifications
• Individuals having multiple separate foci of atypical lobular hyperplasia
• Involvement of both the breasts

Additional and Relevant Useful Information for Atypical Lobular Hyperplasia of Breast:

• The World Health Organization does not recommend using the terminology lobular intraepithelial neoplasia 1 (LIN1) to describe atypical lobular hyperplasia (ALH)

The following DoveMed website links are useful resources for additional information:

https://www.dovemed.com/healthy-living/womens-health/

https://www.dovemed.com/diseases-conditions/cancer/