Definition/General

Introduction:
-A phyllodes tumor with atypia is a phyllodes tumor (usually benign or borderline) that contains foci of atypical epithelial proliferation, such as ADH or ALH.
Origin: The atypia arises from the epithelial component of the phyllodes tumor.
Classification:
-The phyllodes tumor itself is graded as benign, borderline, or malignant
-The presence of atypia is an additional finding.
Epidemiology: It is an uncommon finding.

Clinical Features

Presentation: Presents as a palpable breast mass.
Symptoms: A painless breast lump is the most common symptom.
Risk Factors: Not applicable.
Screening: Mammography and ultrasound show a well-circumscribed mass.

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Gross Description

Appearance:
-A large, well-circumscribed, lobulated mass.
Characteristics: The gross appearance is indistinguishable from a phyllodes tumor without atypia.
Size Location: Size is variable.
Multifocality: Rare.

Microscopic Description

Histological Features: The lesion is a phyllodes tumor with foci of ADH or ALH within the epithelial component.
Cellular Characteristics: The cytological features are those of the specific type of atypia.
Architectural Patterns: The background is that of a phyllodes tumor.
Grading Criteria: The phyllodes tumor is graded based on its stromal features.

Immunohistochemistry

Positive Markers: The IHC profile of the atypical component is similar to that of ADH or ALH.
Negative Markers: Not applicable.
Diagnostic Utility: IHC can be used to characterize the atypical proliferation.
Molecular Subtypes: Not applicable.

Molecular/Genetic

Genetic Mutations: Not well characterized.
Molecular Markers: No specific molecular markers are routinely used for diagnosis.
Prognostic Significance:
-The prognostic significance of atypia within a phyllodes tumor is uncertain, but it may be associated with an increased risk of subsequent carcinoma.
Therapeutic Targets: Treatment is wide local excision.

Differential Diagnosis

Similar Entities: Phyllodes tumor with carcinoma in situ.
Distinguishing Features: The distinction between atypia and carcinoma in situ is based on standard criteria.
Diagnostic Challenges: The main challenge is to identify the focal atypia.
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]

Prognostic Factors

Prognostic factors: [list factors]

Final Diagnosis

Final diagnosis: [complete diagnosis]