Fig 1.
Evidence of VM in equine ocular, oropharyngeal and penile SCC.
CD31/PAS-staining of tumor sections provided evidence of VM in a minimum of 13 lesions as exemplarily shown for an ocular (BOD), an oropharyngeal (JON) and a penile SCC (ERI). Staining revealed hollow structures lined by CD31-negative tumor cells (no brown signal; for controls see S1 Fig) and harboring erythrocytes as revealed by their morphological appearance and slight PAS staining). White frames depict the areas also presented at higher magnification.
Fig 2.
Intralesional presence of VM shown by CD31/KRT/Col4 IF labeling in an ocular lesion.
The Figure depicts a section of an ocular (BOD) SCC IF-stained for CD31 (red signal), KRT (orange signal), and Col4 (green signal). The blue signal reflects DAPI-stained cell nuclei. Individual staining results are presented in black and white in addition to merged images from normal blood vessels and VM structures to allow for direct comparison and optimum signal evaluation.
Fig 3.
Intralesional presence of VM shown by CD31/KRT/Col4 IF labeling in an oropharyngeal lesion.
The Figure shows a section of an oropharyngeal (JON) SCC IF-stained for CD31 (red signal), KRT (orange signal), and Col4 (green signal). DAPI-stained cell nuclei are reflected by a blue signal. Individual staining results are presented in black and white in addition to merged images from normal blood vessels and VM structures to allow for direct comparison and optimum signal evaluation.
Fig 4.
Intralesional presence of VM shown by CD31/KRT/Col4 IF labeling in a penile lesion.
The Figure displays a section of a penile (ERI) SCC IF-stained for CD31 (red signal), KRT (orange signal), and Col4 (green signal). The blue signal is emitted by DAPI-stained cell nuclei. Individual staining results are presented in black and white in addition to merged images from normal blood vessels and VM structures to allow for direct comparison and optimum signal evaluation.
Fig 5.
Mosaic pattern of VM observed in sections of an ocular SCC.
The figure depicts CD31/PAS and CD31/KRT/Col4 IF stained sections of an ocular SCC (MON) exhibiting VM (top row) or normal blood vessels (bottom row). CD31/PAS staining allowed for distinction of pseudo-vessels delimited by tumor cells from normal blood vessels exhibiting a CD31 + endothelial cell lining. Of note, the VM lining also harbored a few CD31 + cells. This finding was confirmed by triple IF staining (bottom row) for CD31 (red signal), KRT (orange signal), and Col4 (green signal). The figure shows merged IF images from normal blood vessels and VM structures for direct comparison, with white arrows pointing to CD31 + cells in VM. Individual staining results presented in black-and-white allowed for optimum signal evaluation.
Fig 6.
The lining of VM channels harbors pericytes as exemplarily shown for an ocular SCC.
The figure presents a section of an ocular SCC (BOD) that was IF-stained for CD31 (red signal), KRT (orange signal), and α-SMA (green signal). The blue signal reflects DAPI-stained cell nuclei. The figures show merged images from normal blood vessels and VM structures for direct comparison. In addition, individual staining results are presented in black-and-white to allow for optimum signal evaluation.
Fig 7.
The lining of VM channels harbors pericytes as exemplarily shown for an oropharyngeal SCC.
The figure depicts a section of an oropharyngeal SCC (JON) that was IF-stained for CD31 (red signal), KRT (orange signal), and α-SMA (green signal). The blue signal is emitted by DAPI-stained cell nuclei. The figures show merged images from normal blood vessels and VM structures for direct comparison. Moreover, individual staining results are presented in black-and-white to allow for optimum signal evaluation.
Fig 8.
The lining of VM channels harbors pericytes as exemplarily shown for a penile SCC.
The figure shows a section of a penile SCC (ERI) IF-stained for CD31 (red signal), KRT (orange signal), and α-SMA (green signal). DAPI-stained cell nuclei are reflected by a blue signal reflects. The figures presents merged images from normal blood vessels and VM structures for direct comparison. Furthermore, individual staining results are presented in black-and-white to allow for optimum signal evaluation.
Table 1.
Grading of the ocular, oronasal, and genital tumors displaying VM.