Definition/General
Introduction:
Phyllodes tumor with villoglandular carcinoma is an extremely rare malignant phyllodes tumor where the stromal component contains villoglandular carcinoma characterized by villous and glandular architecture
This represents a unique form of heterologous phyllodes tumor.
Origin:
Develops from intralobular breast stroma with differentiation toward villoglandular carcinoma
May arise through complex epithelial differentiation of stromal cells with formation of villous structures.
Classification:
WHO Classification categorizes this as malignant phyllodes tumor with heterologous elements
Villoglandular carcinoma component shows characteristic villous and glandular architecture.
Epidemiology:
Exceptionally rare with fewer than 5 cases reported worldwide
Peak age 45-65 years
Female predominance
Clinical behavior similar to other heterologous phyllodes tumors.
Clinical Features
Presentation:
Large, slowly growing breast mass
Usually presents as painless mass
May show gradual enlargement over months to years.
Symptoms:
Progressive breast enlargement
Breast asymmetry
Usually asymptomatic initially
May become symptomatic with large size
Nipple discharge rare.
Risk Factors:
Previous phyllodes tumor history
Middle to older age
Hormonal factors possible
No specific genetic predisposition identified.
Screening:
No specific screening available
Clinical examination for masses
Imaging with mammography and ultrasound
Core needle biopsy for diagnosis.
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Gross Description
Appearance:
Large, well-circumscribed mass with lobulated contour
Cut surface shows gray-white areas with possible papillary or villous appearance
Soft to firm consistency.
Characteristics:
Size typically >4 cm (range 3-12 cm)
Soft to firm consistency
May have characteristic papillary or frond-like areas
Cystic change possible.
Size Location:
Can occur in any breast region
Usually involves moderate to significant breast tissue
Unilateral presentation typical.
Multifocality:
Typically unifocal mass
Multifocal villous areas within tumor
Complex architecture
Local extension uncommon.
Microscopic Description
Histological Features:
Biphasic tumor with epithelial and mesenchymal components
Villoglandular carcinoma areas show villous projections with fibrovascular cores and glandular structures.
Cellular Characteristics:
Columnar to cuboidal epithelial cells lining villous structures
Mild to moderate nuclear atypia
Variable mitotic activity
Mucin production possible.
Architectural Patterns:
Villous projections with central fibrovascular cores
Glandular structures of varying sizes
Papillary configuration
Complex branching pattern.
Grading Criteria:
Usually low to intermediate grade
Mild to moderate nuclear atypia
Low to moderate mitotic rate (<10 per 10 HPF)
Well-differentiated architecture.
Immunohistochemistry
Positive Markers:
Cytokeratins positive (CK7, CK20 variable)
EMA positive
CEA positive
CDX2 may be positive
Mucin stains positive
Epithelial component: CK7+, EMA+.
Negative Markers:
TTF-1 negative
PAX8 negative
Calretinin negative
WT1 negative
p16 usually negative.
Diagnostic Utility:
Cytokeratin profile helps characterize epithelial differentiation
CEA positivity supportive
CDX2 positivity may suggest intestinal-type differentiation.
Molecular Subtypes:
Intestinal-type villoglandular carcinoma
Endocervical-type villoglandular carcinoma
Mixed villoglandular and conventional adenocarcinoma.
Molecular/Genetic
Genetic Mutations:
KRAS mutations possible
PIK3CA mutations
APC gene alterations in intestinal-type
TP53 mutations variable.
Molecular Markers:
Variable Ki-67 proliferation index
Mucin gene expression
Wnt pathway activation possible
E-cadherin expression preserved.
Prognostic Significance:
Generally better prognosis than high-grade carcinomas
Grade and size important prognostic factors
Complete excision crucial for outcome.
Therapeutic Targets:
Conventional chemotherapy for high-grade areas
Targeted therapy based on molecular profile
Hormonal therapy if receptor positive.
Differential Diagnosis
Similar Entities:
Primary villoglandular carcinoma of breast
Metastatic villoglandular carcinoma from cervix or colon
Papillary carcinoma
Adenoid cystic carcinoma.
Distinguishing Features:
Phyllodes with villoglandular: Leaf-like areas, complex architecture
Primary villoglandular: No phyllodes component
Metastatic: Clinical history, imaging.
Diagnostic Challenges:
Recognition of villoglandular features
Distinction from metastatic tumors
Assessment of phyllodes components
Site of origin determination.
Rare Variants:
Villoglandular carcinoma with squamous differentiation
Mixed villoglandular and mucinous carcinoma
Villoglandular with neuroendocrine features.
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]