Definition/General
Introduction:
Apocrine hyperplasia is a benign proliferative breast lesion characterized by a multilayered proliferation of apocrine cells lining the ducts or lobules, without cytological atypia
It is a component of fibrocystic changes.
Origin:
It arises from the terminal duct-lobular unit (TDLU).
Classification:
Apocrine hyperplasia is classified as a benign proliferative breast lesion without atypia.
Epidemiology:
It is a common finding in breast biopsies, especially in the perimenopausal period.
Clinical Features
Presentation:
Apocrine hyperplasia is an incidental microscopic finding.
Symptoms:
Asymptomatic.
Risk Factors:
There are no well-established risk factors.
Screening:
Apocrine hyperplasia is a microscopic finding and not specifically screened for.
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Gross Description
Appearance:
There are no specific gross findings.
Characteristics:
Gross findings are not specific for this microscopic diagnosis.
Size Location:
Gross findings are not specific for this microscopic diagnosis.
Multifocality:
Often multifocal.
Microscopic Description
Histological Features:
The ducts and lobules are lined by more than two layers of apocrine cells
The cells form papillary tufts or mounds
The cells have abundant, granular, eosinophilic cytoplasm and apical snouts.
Cellular Characteristics:
The nuclei are round with prominent, eosinophilic nucleoli
There is no significant cytological atypia.
Architectural Patterns:
The proliferation can be papillary or solid.
Grading Criteria:
This is a benign lesion.
Immunohistochemistry
Positive Markers:
The cells are positive for GCDFP-15 and AR
They are typically negative for ER and PR.
Negative Markers:
Usually negative for ER and PR.
Diagnostic Utility:
IHC is not usually necessary for diagnosis.
Molecular Subtypes:
Molecular subtyping is not relevant for this benign condition.
Molecular/Genetic
Genetic Mutations:
This is a benign condition and is not associated with specific genetic mutations.
Molecular Markers:
No specific molecular markers are routinely used for diagnosis.
Prognostic Significance:
Apocrine hyperplasia without atypia is not associated with an increased risk of developing invasive breast cancer.
Therapeutic Targets:
No treatment is required.
Differential Diagnosis
Similar Entities:
Apocrine atypia
Apocrine DCIS.
Distinguishing Features:
Apocrine atypia and DCIS show increasing degrees of cytological atypia and architectural complexity.
Diagnostic Challenges:
The main challenge is to assess for the presence of atypia.
Rare Variants:
There are no specific rare variants.
Sample Pathology Report
Template Format
Sample Pathology Report
Complete Report: This is an example of how the final pathology report should be structured for this condition.
Specimen Information
[specimen type], measuring [size] cm in greatest dimension
Diagnosis
[diagnosis name]
Classification
Classification: [classification system] [grade/type]
Histological Features
Shows [architectural pattern] with [nuclear features] and [mitotic activity]
Size and Extent
Size: [X] cm, extent: [local/regional/metastatic]
Margins
Margins are [involved/uninvolved] with closest margin [X] mm
Lymphovascular Invasion
Lymphovascular invasion: [present/absent]
Lymph Node Status
Lymph nodes: [X] positive out of [X] examined
Special Studies
IHC: [marker]: [result]
Molecular: [test]: [result]
[other study]: [result]
Final Diagnosis
Final diagnosis: [complete diagnosis]