Broad Fibrovascular Cores in Papillary Lesions of the Breast
Broad Fibrovascular Cores in Papillary Lesions of the Breast
The materials were obtained from patients at the Social Insurance Kurume Daiichi Hospital (Kurume, Japan) over a period of 5 years from 2008 to 2012. All patients were female.
A broad fibrovascular core was defined as stromal tissue core with a minor (cross-sectional) axis >100 μm and measuring >1×10 μm in size (area) (figure 2). Papillomas were intraductal benign papillary lesions characterised by finger-like fibrovasucular cores covered by epithelial and myoepithelial layers. Ductal adenomas were well-circumscribed sclerosing papilloma, with benign glandular proliferation located, at least in part, within a duct lumen, usually accompanied by dense scar-like fibrosis and surrounded by a thick fibrous wall. Atypical papillary lesions corresponded to B3 lesion of uncertain malignant potential by the National Health Service Breast Screening Programme, that is, showing portions manifesting architectural and cytological atypia that fell short of the diagnosis of intraductal (encapsulated) papillary carcinomas; or small focus (<3 mm) of ADH within a background of papillomas in the present study. Papillary carcinomas included intraductal papillary carcinomas (papillary DCIS), encapsulated papillary carcinomas and solid papillary carcinomas. All the papillary lesions (papillomas and carcinomas) in this study were divided into predominantly papillary or mixed patterns (mixed with solid, cribriform and tubular structures). The papillary predominant pattern was defined as having predominantly (>80%) papillary structure in the specimens (figure 3A–D), whereas all others were defined as mixed pattern (figure 3E–H).
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Figure 2.
Example of broad stroma (a minor (cross-sectional) axis >100 μm and area (size) >1×10 μm) in a papillary carcinoma. The area of the fibrovascular core A, which is considered a 'broad' fibrovascular core, whereas that of B and C (a minor axis <100 μm and area <1×10 μm) are not considered a 'broad' fibrovascular core.
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Figure 3.
The architectural pattern of papillary lesions was classified into papillary pattern, which were defined as those showing papillary predominant structures in >80% of the tumour (A–D) and mixed papillary pattern (E–H). (A, B) Papillomas with papillary predominant patterns. The papilloma shows a 'papillary growth' pattern, consisting of epithelial and myoepthelial cells associated with relatively even (A) or thin (B) distribution of fibrovascular cores (stroma). (C, D) Papillary carcinomas with papillary predominant patterns. The tumour shows a 'papillary predominant growth' pattern characterised by sclerotic broad fibrovascular cores covered by a neoplastic epithelium without myoepithelial cells and the cells are arranged in finger-like projections. The stromas of the 'finger-like' (branching) part are scant, but the 'palm' areas (fibrovascular cores) are broad, showing uneven distribution of the stroma. (E) A papilloma with mixed pattern. The papilloma shows epithelial hyperplasia exhibiting a mixed ductal and cribriform structure consisting of epithelial and myoepthelial cells covered by the fibrovascular cores. (F) A papilloma with mixed (solid) pattern. The papilloma shows usual ductal hyperplasia with proliferation of epithelial cells around some of the broad fibrovascular cores. (G, H) Papillary carcinomas with mixed pattern. The tumours show solid papillary proliferation surrounding the broad fibrovascular cores.
The patient cohort consisted of cases with core needle biopsies (CNB) using a 14-gauge needle and Mammotome (MMT) biopsies using an 11-gauge vacuum-assisted instrument. All MMT and CNB biopsies were done under ultrasound guidance. When the broad fibrovascular cores were identified by low magnification, the minor axis and size were manually confirmed using an eyepiece micrometer (square, 10 mm/10 units, Olympus). The number of cases with broad fibrovascular cores was compared among papillomas (and ductal adenomas), atypical papillary lesions and papillary carcinomas. The architectural (papillary predominant or mixed) patterns were also compared among papillomas and papillary carcinomas.
Subsequently, the broad fibrovascular cores were evaluated in the corresponding resection specimens of papillary lesions, most of which corresponded to the needle biopsies, although some were without previous needle biopsies. The densities of broad fibrovascular cores between papillomas and carcinomas within papillary predominant and mixed patterns as defined above were also compared. In each lesion, the field of highest density of broad fibrovascular cores was identified by scanning the tumour sections at low-power magnification (40×). If the whole tumour was not included in one slide, additional sections were evaluated. After the field of the highest broad fibrovascular core density was identified, the number of individual broad fibrovascular cores was manually counted at 100× (1 mm per field) (figure 4). A score was given equalling the number of broad fibrovascular cores counted. When the number of broad fibrovascular cores was 10 or more or when the broad fibrovascular cores occupied 1/4 or more of the microscopic field (0.25 mm), especially if they were sclerosed and expanded (any shapes including rectangular or branching), a score of 10 was given. Thus, the score of broad fibrovascular core density would theorectically range from 0 to 10.
(Enlarge Image)
Figure 4.
Example of counting broad fibrovascular core density (1 mm per field). The number of broad fibrovascular cores in tumours was counted.
Materials and Methods
The materials were obtained from patients at the Social Insurance Kurume Daiichi Hospital (Kurume, Japan) over a period of 5 years from 2008 to 2012. All patients were female.
Definitions
A broad fibrovascular core was defined as stromal tissue core with a minor (cross-sectional) axis >100 μm and measuring >1×10 μm in size (area) (figure 2). Papillomas were intraductal benign papillary lesions characterised by finger-like fibrovasucular cores covered by epithelial and myoepithelial layers. Ductal adenomas were well-circumscribed sclerosing papilloma, with benign glandular proliferation located, at least in part, within a duct lumen, usually accompanied by dense scar-like fibrosis and surrounded by a thick fibrous wall. Atypical papillary lesions corresponded to B3 lesion of uncertain malignant potential by the National Health Service Breast Screening Programme, that is, showing portions manifesting architectural and cytological atypia that fell short of the diagnosis of intraductal (encapsulated) papillary carcinomas; or small focus (<3 mm) of ADH within a background of papillomas in the present study. Papillary carcinomas included intraductal papillary carcinomas (papillary DCIS), encapsulated papillary carcinomas and solid papillary carcinomas. All the papillary lesions (papillomas and carcinomas) in this study were divided into predominantly papillary or mixed patterns (mixed with solid, cribriform and tubular structures). The papillary predominant pattern was defined as having predominantly (>80%) papillary structure in the specimens (figure 3A–D), whereas all others were defined as mixed pattern (figure 3E–H).
(Enlarge Image)
Figure 2.
Example of broad stroma (a minor (cross-sectional) axis >100 μm and area (size) >1×10 μm) in a papillary carcinoma. The area of the fibrovascular core A, which is considered a 'broad' fibrovascular core, whereas that of B and C (a minor axis <100 μm and area <1×10 μm) are not considered a 'broad' fibrovascular core.
(Enlarge Image)
Figure 3.
The architectural pattern of papillary lesions was classified into papillary pattern, which were defined as those showing papillary predominant structures in >80% of the tumour (A–D) and mixed papillary pattern (E–H). (A, B) Papillomas with papillary predominant patterns. The papilloma shows a 'papillary growth' pattern, consisting of epithelial and myoepthelial cells associated with relatively even (A) or thin (B) distribution of fibrovascular cores (stroma). (C, D) Papillary carcinomas with papillary predominant patterns. The tumour shows a 'papillary predominant growth' pattern characterised by sclerotic broad fibrovascular cores covered by a neoplastic epithelium without myoepithelial cells and the cells are arranged in finger-like projections. The stromas of the 'finger-like' (branching) part are scant, but the 'palm' areas (fibrovascular cores) are broad, showing uneven distribution of the stroma. (E) A papilloma with mixed pattern. The papilloma shows epithelial hyperplasia exhibiting a mixed ductal and cribriform structure consisting of epithelial and myoepthelial cells covered by the fibrovascular cores. (F) A papilloma with mixed (solid) pattern. The papilloma shows usual ductal hyperplasia with proliferation of epithelial cells around some of the broad fibrovascular cores. (G, H) Papillary carcinomas with mixed pattern. The tumours show solid papillary proliferation surrounding the broad fibrovascular cores.
Broad Fibrovascular Cores in Papillary Lesions in Needle Biopsy Specimens
The patient cohort consisted of cases with core needle biopsies (CNB) using a 14-gauge needle and Mammotome (MMT) biopsies using an 11-gauge vacuum-assisted instrument. All MMT and CNB biopsies were done under ultrasound guidance. When the broad fibrovascular cores were identified by low magnification, the minor axis and size were manually confirmed using an eyepiece micrometer (square, 10 mm/10 units, Olympus). The number of cases with broad fibrovascular cores was compared among papillomas (and ductal adenomas), atypical papillary lesions and papillary carcinomas. The architectural (papillary predominant or mixed) patterns were also compared among papillomas and papillary carcinomas.
Broad Fibrovascular Cores in Resected Papillary Lesions
Subsequently, the broad fibrovascular cores were evaluated in the corresponding resection specimens of papillary lesions, most of which corresponded to the needle biopsies, although some were without previous needle biopsies. The densities of broad fibrovascular cores between papillomas and carcinomas within papillary predominant and mixed patterns as defined above were also compared. In each lesion, the field of highest density of broad fibrovascular cores was identified by scanning the tumour sections at low-power magnification (40×). If the whole tumour was not included in one slide, additional sections were evaluated. After the field of the highest broad fibrovascular core density was identified, the number of individual broad fibrovascular cores was manually counted at 100× (1 mm per field) (figure 4). A score was given equalling the number of broad fibrovascular cores counted. When the number of broad fibrovascular cores was 10 or more or when the broad fibrovascular cores occupied 1/4 or more of the microscopic field (0.25 mm), especially if they were sclerosed and expanded (any shapes including rectangular or branching), a score of 10 was given. Thus, the score of broad fibrovascular core density would theorectically range from 0 to 10.
(Enlarge Image)
Figure 4.
Example of counting broad fibrovascular core density (1 mm per field). The number of broad fibrovascular cores in tumours was counted.
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