Definition/General
Introduction:
A giant fibroadenoma is a fibroadenoma that is larger than 5 cm or weighs more than 500 grams
It is a benign tumor, but its large size can cause clinical concern.
Origin:
It arises from the terminal duct-lobular unit (TDLU).
Classification:
It is a subtype of fibroadenoma based on size.
Epidemiology:
It is uncommon and is most often seen in adolescents and young women.
Clinical Features
Presentation:
Presents as a large, rapidly growing, painless, mobile mass that can cause significant breast asymmetry.
Symptoms:
A large, rapidly enlarging breast lump is the most common symptom.
Risk Factors:
There are no well-established risk factors.
Screening:
Ultrasound shows a large, well-defined, hypoechoic mass.
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Gross Description
Appearance:
A large, well-circumscribed, encapsulated, gray-white mass.
Characteristics:
The cut surface is firm and whorled.
Size Location:
Defined by its large size (>5 cm).
Multifocality:
Usually unifocal.
Microscopic Description
Histological Features:
The histology is identical to that of a conventional fibroadenoma, with a biphasic proliferation of benign glands and stroma
The stroma is typically not as cellular as in a juvenile fibroadenoma.
Cellular Characteristics:
The epithelial and stromal cells are benign.
Architectural Patterns:
Can be intracanalicular, pericanalicular, or mixed.
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:
This is a benign lesion with an excellent prognosis
Recurrence is rare after complete excision.
Therapeutic Targets:
Treatment is surgical excision.
Differential Diagnosis
Similar Entities:
Benign phyllodes tumor
Juvenile fibroadenoma.
Distinguishing Features:
Benign phyllodes tumors have a more cellular stroma and a leaf-like architecture
Juvenile fibroadenomas also have a more cellular stroma.
Diagnostic Challenges:
The main challenge is distinguishing a giant fibroadenoma from a benign phyllodes tumor, which is important as phyllodes tumors have a higher risk of recurrence.
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]