Comparative Analysis of Canine Testicular Tumours with Use of The Histopathological Analysis and Flow Cytometry

Tumori sjemenika pasa spadaju u najčešće tumore spolnog sustava te među najčešće tumore pasa uopće. Većina tumora se dijagnosticira u kasnijoj fazi kada već dođe do povećanja sjemenika, pri čemu se kao jedina i najbolja metoda liječenja koristi kastracija, nakon koje se može postaviti i konačna dijagnoza na temelju histopatološke pretrage zahvaćenog sjemenika. U ovom istraživanju je provedena histopatološka analiza arhiviranih uzoraka najčešćih tumora sjemenika pasa (9 uzoraka) i jednom uzorku nepromijenjenog sjemenika, te je provedena histopatološka klasifikacija. Isti uzorci su podvrgnuti analizi DNK metodom protočne citometrije kako bi se utvrdio udio tumorskih stanica u pojedinim fazama staničnog ciklusa. Provedenom komparativnom analizom rezultata histopatološke pretrage i protočne citometrije se nastojalo utvrditi da li postoji korelacija između histološke klasifikacije tipova tumora i rezultata protočne citometrije odnosno jesu li promjene u genetskom materijalu (aneuploidija, povećan broj mitoza) ili fizikalnim svojstvima (veličina, oblik, granuliranost) tumorskih stanica povezane sa histološkim tipom tumora, a što je vrlo često kod tumora sjemenika muškaraca. Provedbom obje analize je utvrđeno da histopatološka pretraga predstavlja objektivnu dijagnostičku metodu za razlikovanje pojedinih tipova tumora sjemenika u pasa. Primjenom metode protočne citometrije na uzorcima sjemenika pasa mogu se dobiti neke nove informacije o svojstvima stanice, (broj kromosoma, postotak stanica u pojedinoj fazi staničnog ciklusa). Dobiveni su rezultati protočne citometrije koji iako nisu bili dostatni i dovoljno precizni za donošenje definitivnog zaključka o karakteristikama istraživanih neoplastičnih promjena, pokazuju da je primjenom metode protočne citometrije na uzorcima sjemenika pasa moguće dobiti nove informacije o svojstvima stanice (broj kromosoma, postotak stanica u pojedinoj fazi staničnog ciklusa. Kako bi se protočna citometrija te njezini rezultati mogli objektivnije analizirati te koristiti u dijagnostici neoplazija testisa u pasa potrebno je optimizirati i standardizirati metodu te postaviti detaljne dijagnostičke kriterije. Takvi takvi kriteriji bi se zatim trebali komparirati s rezultatima histopatološke analize tumora za što je potrebno provesti opsežnije istraživanje na znatno većem broju uzoraka tumorozno promijenjenih i patološki nepromijenjenih sjemenika. 33 Metoda protočne citometrije pruža mnoge mogućnosti i ostavlja puno prostora za napredak u dijagnostici tumora sjemenika pasa osobito ako je kombinirana s do sada uhodanim metodama pretrage kao što su histopatološka analiza tumora sjemenika.Canine testicular tumours are one of the most frequent tumours of the dog genital system and among the most frequent tumours of the dogs generally. Most tumours are diagnosed at a later stage when enlargement of the testicles is already present wherein the only and the best treatment method used is castration, after which a final diagnosis can be set up based on histopathological analysis of affected testicle. In this research, histopathological analysis was conducted on the archive samples of the most frequent canine testicular tumours (9 samples) and on one sample without the presence of a tumour changes, also the histopathological classification of the tumours has been conducted. The same samples were exposed to DNA analysis using flow cytomety to determine the proportion of tumor cells in certain stages of the cell cycle. With conducted comparative analysis of the results of histopathological evaluation and flow cytometry we tried to determine wheter there is a correlation between the histologically classified types of tumors and results of flow cytometry or whether changes in the genetic material (aneuploidy, an increased number of mitosis) or physical properties (size, shape, granularity) of tumor cells were associated with histological type of tumor, which is very common in testicular tumors of men. With implementation of both studies, it was found that a histopathological evealuation is an objective diagnostic method for distinguishing certain types of canine testicular tumors. The obtained results of flow cytometry, although they were not sufficient and precise enough for making a definitive conclusion, on the characteristics of the studied neoplastic changes show that with usage of the method of flow cytometry on the samples of canine testicles it is possible to get some new information about the properties of the cells (the number of chromosomes, the percentage of cells in each stage of the cell cycle). In order to flow cytometry and its results can be objectively analyzed and used in the diagnosis of testicular neoplasia in dogs it is necessary to optimize and standardize the method and detailed set of diagnostic criteria. Such criteria should then be compared with the results of histopathological analysis of the 35 tumours for what is necessary to conduct extensive research on a much larger number of samples of unmodified and neoplasticaly modified testicles. Flow cytometry provides many possibilities and leaves much space for improvement in the diagnosis of canine testicular tumours, especially if it was combined with well-established methods such as histopathological evaluation of testicular tumours