Definition/General
Introduction:
A complex fibroadenoma is a fibroadenoma that contains one or more complex features, including cysts (>3mm), sclerosing adenosis, epithelial calcifications, or papillary apocrine change
These features distinguish it from a simple fibroadenoma.
Origin:
It arises from the terminal duct-lobular unit (TDLU).
Classification:
It is a subtype of fibroadenoma.
Epidemiology:
They are common, and the frequency increases with age.
Clinical Features
Presentation:
Presents as a painless, firm, mobile, well-circumscribed, rubbery mass, similar to a simple fibroadenoma.
Symptoms:
A painless, mobile lump is the most common symptom.
Risk Factors:
There are no well-established risk factors.
Screening:
On mammography, they appear as a well-circumscribed, oval mass that may have calcifications.
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Gross Description
Appearance:
A well-circumscribed, encapsulated, firm, gray-white mass.
Characteristics:
The cut surface is whorled and may have visible cysts.
Size Location:
Size is variable.
Multifocality:
Can be multiple.
Microscopic Description
Histological Features:
The lesion is a fibroadenoma with one or more of the following features: cysts (>3mm), sclerosing adenosis, epithelial calcifications, or papillary apocrine change.
Cellular Characteristics:
The epithelial and stromal cells are benign.
Architectural Patterns:
The background is that of a fibroadenoma, with the addition of the complex features.
Grading Criteria:
This is a benign lesion.
Immunohistochemistry
Positive Markers:
The IHC profile is similar to that of a conventional fibroadenoma.
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:
Complex fibroadenomas are associated with a small increased risk (about 2-3 fold) of developing invasive breast cancer.
Therapeutic Targets:
Treatment is usually conservative (observation)
Excision may be performed for large or symptomatic lesions.
Differential Diagnosis
Similar Entities:
Simple fibroadenoma
Phyllodes tumor.
Distinguishing Features:
Simple fibroadenomas lack the complex features
Phyllodes tumors have a more cellular stroma and a leaf-like architecture.
Diagnostic Challenges:
The main challenge is to identify the complex features and to distinguish it from a phyllodes tumor.
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]