Definition/General
Introduction:
Carcinoma arising within a fibroadenoma is a rare event
The carcinoma can be in situ or invasive, and of ductal or lobular type
The most common type is lobular carcinoma in situ (LCIS).
Origin:
The carcinoma arises from the epithelial component of the fibroadenoma.
Classification:
The carcinoma is classified and graded according to the standard criteria for breast cancer.
Epidemiology:
It is most common in perimenopausal and postmenopausal women, at an older age than patients with simple fibroadenomas.
Clinical Features
Presentation:
Presents as a palpable breast mass, often with a recent history of growth.
Symptoms:
A breast lump is the most common symptom.
Risk Factors:
The risk factors are those for breast cancer in general.
Screening:
Mammography may show a well-circumscribed mass with suspicious features, such as indistinct margins or calcifications.
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Gross Description
Appearance:
The gross appearance is usually that of a fibroadenoma
The carcinomatous component may not be grossly apparent.
Characteristics:
Gross findings are not specific for this microscopic diagnosis.
Size Location:
Gross findings are not specific for this microscopic diagnosis.
Multifocality:
Gross findings are not specific for this microscopic diagnosis.
Microscopic Description
Histological Features:
The lesion is a fibroadenoma with a focus of carcinoma (in situ or invasive)
The carcinoma is confined to the fibroadenoma or may extend into the surrounding tissue.
Cellular Characteristics:
The cytological features are those of the specific type of carcinoma.
Architectural Patterns:
The background is that of a fibroadenoma.
Grading Criteria:
The carcinoma is graded according to standard criteria.
Immunohistochemistry
Positive Markers:
The IHC profile is that of the specific carcinoma type.
Negative Markers:
Not typically required for diagnosis.
Diagnostic Utility:
IHC is used to classify the carcinoma and to determine ER, PR, and HER2 status.
Molecular Subtypes:
The molecular subtype is that of the carcinoma.
Molecular/Genetic
Genetic Mutations:
The genetic alterations are those of the specific carcinoma type.
Molecular Markers:
No specific molecular markers are routinely used for diagnosis.
Prognostic Significance:
The prognosis is determined by the type, grade, and extent of the carcinoma
Carcinoma in situ arising in a fibroadenoma has an excellent prognosis
The prognosis of invasive carcinoma is similar to that of invasive carcinoma of the same size and grade arising in the native breast.
Therapeutic Targets:
Treatment is based on the characteristics of the carcinoma and follows standard guidelines for breast cancer.
Differential Diagnosis
Similar Entities:
Fibroadenoma with atypia
Phyllodes tumor with carcinoma.
Distinguishing Features:
The distinction between atypia and carcinoma in situ is based on standard criteria
Carcinoma can also arise in a phyllodes tumor.
Diagnostic Challenges:
The main challenge is to identify the carcinoma within the fibroadenoma, which can be focal.
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]