Definition/General
Introduction:
An adenosis tumor is a rare benign breast lesion where sclerosing adenosis forms a prominent, well-circumscribed mass
It is a localized, tumorous form of sclerosing adenosis.
Origin:
It arises from the terminal duct-lobular unit (TDLU).
Classification:
It is classified as a benign proliferative breast lesion without atypia.
Epidemiology:
It is a rare lesion, most often found in women in their 40s and 50s.
Clinical Features
Presentation:
It presents as a palpable, firm, mobile mass, which can be clinically suspicious for malignancy.
Symptoms:
A painless breast lump is the most common symptom.
Risk Factors:
There are no well-established risk factors for adenosis tumors.
Screening:
Mammographically, it can appear as a well-circumscribed or spiculated mass, often with calcifications.
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Gross Description
Appearance:
A well-circumscribed, firm, rubbery, gray-white mass.
Characteristics:
The size is variable, but it typically forms a distinct tumorous nodule.
Size Location:
Can occur anywhere in the breast.
Multifocality:
Usually unifocal.
Microscopic Description
Histological Features:
The lesion is composed of a well-circumscribed, nodular proliferation of glands characteristic of sclerosing adenosis
The glands are compressed and distorted in a dense, sclerotic stroma
A myoepithelial layer is preserved.
Cellular Characteristics:
The epithelial and myoepithelial cells are bland.
Architectural Patterns:
The key feature is the tumorous, nodular growth of sclerosing adenosis.
Grading Criteria:
This is a benign lesion.
Immunohistochemistry
Positive Markers:
The myoepithelial cell layer is highlighted by myoepithelial markers such as p63 and calponin.
Negative Markers:
Not typically required for diagnosis.
Diagnostic Utility:
IHC for myoepithelial markers is useful to confirm the benign nature of the lesion and to differentiate it from invasive carcinoma.
Molecular Subtypes:
Molecular subtyping is not relevant for this benign condition.
Molecular/Genetic
Genetic Mutations:
Adenosis tumor 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:
An adenosis tumor is a benign lesion
It is associated with a small increased risk of developing invasive breast cancer, similar to sclerosing adenosis.
Therapeutic Targets:
Surgical excision is often performed for diagnosis and to relieve symptoms.
Differential Diagnosis
Similar Entities:
Invasive ductal carcinoma, especially tubular carcinoma
Fibroadenoma.
Distinguishing Features:
Tubular carcinoma lacks a myoepithelial layer
A fibroadenoma has a different stromal and epithelial arrangement.
Diagnostic Challenges:
The main challenge is distinguishing an adenosis tumor from invasive carcinoma, especially on a core needle biopsy.
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]