Morphological and immunohistochemical examination of tumor cells in Marek’s disease

Abstract

In this paper are described the macroscopic, microscopic and immunophenotypic characteristics of tumors in Marek’s disease (MD). Liver, kidneys, lungs, heart, proventriclus, ovary and nerves of sciatic plexus collected from 20 chickens aged 8 to 24 weeks were examined. Lymphoproliferative enlargement in various organs of focal and diffuse character was found. The affected organs were enlarged, compact and very brittle, irregular in shape, grayish-red or grayish-white and of fatty consistency. Most often characteristic changes were in the spleen, liver, proventriculus and ovary that usually had a compact or ribbed, fatty cauliflower like formation, different in size. On histological examination proliferation of small and medium size lymphocytes, lymphoblast cells, Marek’s disease cells and activated reticulum cells were found. Tumor proliferates predominantly consisted of lymphoblasts and had all the characteristics of a lymphoma. Immunohistochemical analysis revealed that lymphoma cells in MD are of CD3 + phenotype. In liver proliferates numerous CD79+ cells were found perivasculary, which is an interesting finding demanding further research.

U ovom radu su opisane makroskopske, mikroskopske i imunofenotipske karakteristike tumora kod Marekove bolesti (MB). Ispitivanjem su bili obuhvaćeni jetra, bubreg, pluća, srce, žlezdani želudac, jajnik i nervi ishijadičnog pleksusa dvadeset pilića starosti između8i24 nedelje. U ispitivanom materijalu ustanovljeno je limfoproliferativno bujanje u različitim organima, fokalnog ili difuznog karaktera, pri čemu su zahvaćeni organi znatno povećani, kompaktni i veoma krti, često nepravilnog oblika, sivocrveni ili sivobeli, slaninastog izgleda. Najčešće i najkarakterističnije su bili promenjeni slezina, jetra, žlezdani želudac, jajnici koji obično predstavljaju kompaktne ili izbrazdane tvorevine poput karfiola, slaninastog izgleda i različite veličine. Histološki, u organima se nalaze proliferati malih i srednjih limfocita, zatim limfoblasta, ćelija Marekove bolesti i aktivisane retikulumske ćelije. Tumorski proliferati su predominantno sastavljeni od limfoblasta i imaju sve karakteristike limfoma. Imunohistohemijskom analizom je ustanovljeno da su ćelije limfoma kod MB predominantno T ćelijskog tipa, CD3 fenotipa. U proliferatu u jetri su nađene i brojne CD79 pozitivne ćelije lokalizovane perivaskularno, što predstavlja interesantan nalaz i zahteva dalja ispitivanja.