Canine classical seminoma: a specific malignant type with human classifications is highly correlated with tumor angiogenesis.
BACKGROUND
Human seminoma is classified as classical seminoma (SE) and spermatocytic seminoma (SS). Human SE is known to be more malignant and metastasizing more frequently than SS. Tumor angiogenesis is highly related with tumor progression and metastasis, with microvessel density (MVD) being an important parameter of metastatic potential. Canine seminoma is not yet well-established as SE or SS type including correlation with angiogenesis. We classified canine SE and SS, and then compared them to tumor associated vessels.


METHODS
Twenty-three cases of canine seminomas (2 intratubular, 9 diffuse, and 12 intratubular/diffuse seminomas showing both intratubular and diffuse patterns) were classified as SE or SS by immunohistochemistry (IHC) using monoclonal antibody against PLAP and by PAS stain. The histopathological data were then compared to see if there was a correlation with SE or SS. Angiogenesis of seminomas were evaluated by immunohistochemical assay using polyclonal antibody against Von Willebrand factor (vWF) and by calculating the means of MVD, vessels area and perimeters using computerized image analysis. Statistical Package for Social Sciences (SPSS) program was used for various statistical analyses.


RESULTS
The numbers of PLAP+/PAS+ canine SEs were 8/23 (34.8%) and PLAP-/PAS- SSs were 15/23 (61.2%). All SE cases (8/8, 100%) were intratubular/diffuse types. SS types included 2 intratubular (2/15, 13.3%), 9 diffuse (9/15, 60%), and 4 intratubular/diffuse (4/15, 26.7%) types. MVD and vascular parameters in SEs were significantly higher than in SSs, showing the highest value in the intratubular/diffuse type. Seminomas observed with neoplastic cells invasion of vessels presented higher perimeter and area values than seminomas without conformed neoplastic cells invasion.


CONCLUSIONS
In this study, we demonstrated a positive relationship between canine SE and tumor angiogenesis. Furthermore, we also showed that a tumor cells invasion of vessels were a correlated vascular parameter. Although metastasis of canine seminomas has rarely been reported, our results support that canine SE could have high metastatic potential similar to the human counterpart. Further studies are required to clarify the relationship between canine SE and clinical data with metastatic factors.
Department of Veterinary Pathology, Small Animal Tumor Diagnostic Center, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Kwangjin-gu, Seoul 143-701, Korea.
Jong-Hyuk
JH
Kim
Chi-Ho
CH
Yu
Ji-Young
JY
Yhee
Keum-Soon
KS
Im
Na-Hyun
NH
Kim
Jung-Hyang
JH
Sur
D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D014408:Biomarkers, Tumor / Q000032:analysis; D004283:Dog Diseases / Q000145:classification / Q000378:metabolism / Q000473:pathology*; D004285:Dogs; D058851:GPI-Linked Proteins; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D055806:Microvessels / Q000473:pathology; D009361:Neoplasm Invasiveness; D009389:Neovascularization, Pathologic / Q000145:classification / Q000378:metabolism / Q000662:veterinary*; D017430:Prostate-Specific Antigen / Q000032:analysis; D018239:Seminoma / Q000098:blood supply / Q000737:chemistry / Q000145:classification / Q000556:secondary / Q000662:veterinary*; D013194:Staining and Labeling; D009626:Terminology as Topic; D013736:Testicular Neoplasms / Q000098:blood supply / Q000737:chemistry / Q000145:classification / Q000473:pathology / Q000662:veterinary*; D014841:von Willebrand Factor / Q000032:analysis
D014408:Biomarkers, Tumor; D058851:GPI-Linked Proteins; D007527:Isoenzymes; D014841:von Willebrand Factor; D000469:Alkaline Phosphatase; C019839:alkaline phosphatase, placental; D017430:Prostate-Specific Antigen