Definition/General
Introduction:
Cystic hypersecretory hyperplasia (CHH) is a benign proliferative breast lesion characterized by dilated ducts and acini filled with eosinophilic, thyroid colloid-like secretions
It can be associated with atypia (atypical CHH) and DCIS.
Origin:
It arises from the terminal duct-lobular unit (TDLU).
Classification:
It is classified as a benign proliferative breast lesion
It exists on a spectrum with cystic hypersecretory carcinoma in situ.
Epidemiology:
It is a rare lesion, most often found as an incidental finding.
Clinical Features
Presentation:
It is typically an incidental microscopic finding.
Symptoms:
Asymptomatic.
Risk Factors:
There are no well-established risk factors.
Screening:
It can be associated with microcalcifications on mammography.
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Gross Description
Appearance:
There are no specific gross findings
Cysts may be present.
Characteristics:
Gross findings are not specific for this microscopic diagnosis.
Size Location:
Gross findings are not specific for this microscopic diagnosis.
Multifocality:
Can be multifocal.
Microscopic Description
Histological Features:
The ducts and acini are cystically dilated and filled with abundant, eosinophilic, hard, cracked secretions that resemble thyroid colloid
The lining epithelium is typically flattened or cuboidal and can be hyperplastic.
Cellular Characteristics:
In CHH without atypia, the cells are bland
In atypical CHH, the cells show low-grade nuclear atypia, similar to that seen in FEA or low-grade DCIS.
Architectural Patterns:
The key feature is the cystic dilation with colloid-like secretions
The epithelium can be flat or form micropapillary projections.
Grading Criteria:
This is a benign lesion, but it can be associated with atypia.
Immunohistochemistry
Positive Markers:
The epithelial cells are positive for cytokeratins and are often ER-positive.
Negative Markers:
Not typically required for diagnosis.
Diagnostic Utility:
IHC is not usually necessary for diagnosis.
Molecular Subtypes:
Molecular subtyping is not relevant for this benign condition.
Molecular/Genetic
Genetic Mutations:
Not well characterized.
Molecular Markers:
No specific molecular markers are routinely used for diagnosis.
Prognostic Significance:
CHH without atypia is a low-risk lesion
Atypical CHH is a risk factor for breast cancer, similar to ADH.
Therapeutic Targets:
Management depends on the presence of atypia
If atypia is present, excision is often recommended.
Differential Diagnosis
Similar Entities:
Fibrocystic changes
Secretory carcinoma.
Distinguishing Features:
Simple cysts in fibrocystic change do not have the characteristic hypersecretory features
Secretory carcinoma has a different type of secretion and is an invasive malignancy.
Diagnostic Challenges:
The main challenge is to assess for the presence of atypia, which can be subtle.
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]