Definition/General
Introduction:
Tubular adenosis is a rare benign proliferative breast lesion characterized by a proliferation of small, uniform, closely packed tubules
It is a variant of 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 as an incidental finding.
Clinical Features
Presentation:
It is typically an incidental microscopic finding.
Symptoms:
Asymptomatic.
Risk Factors:
Not applicable.
Screening:
It can be associated with microcalcifications on mammography.
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Gross Description
Appearance:
There are no specific gross findings.
Characteristics:
Not applicable.
Size Location:
Not applicable.
Multifocality:
Can be multifocal.
Microscopic Description
Histological Features:
The lesion is composed of a well-circumscribed proliferation of small, round to oval tubules
The tubules are closely packed and are lined by a single layer of epithelial cells and a prominent outer myoepithelial cell layer.
Cellular Characteristics:
The epithelial cells are bland, with small, uniform nuclei
The myoepithelial cells are conspicuous.
Architectural Patterns:
The key feature is the proliferation of uniform, back-to-back tubules.
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 applicable.
Diagnostic Utility:
IHC for myoepithelial markers is useful to confirm the benign nature of the lesion and to differentiate it from tubular carcinoma.
Molecular Subtypes:
Not applicable.
Molecular/Genetic
Genetic Mutations:
Not applicable.
Molecular Markers:
No specific molecular markers are routinely used for diagnosis.
Prognostic Significance:
Tubular adenosis is a benign lesion and is not considered to be a significant risk factor for breast cancer.
Therapeutic Targets:
No treatment is required.
Differential Diagnosis
Similar Entities:
Tubular carcinoma
Sclerosing adenosis.
Distinguishing Features:
Tubular carcinoma lacks a myoepithelial layer
Sclerosing adenosis has more stromal sclerosis and glandular distortion.
Diagnostic Challenges:
The main challenge is distinguishing tubular adenosis from tubular carcinoma
The presence of a myoepithelial layer is the key distinguishing feature.
Rare Variants:
Not applicable.
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]