3.2. Microscopic finding
Many clusters of lymphocystis cellswere observed in the connective
tissues beneath the epidermis (Fig. 1B) at fins, inner layer of operculum,
and gills. Numerous hypertrophied cells with basophilic intracytoplasmic
inclusion bodies were in the connective tissues of dermis and
between the scales. The lymphocystis cells were also detectable in
skeletal muscle, gill lamellae and visceral organs including spleen, head
and trunk kidney. The lymphocystis-granulomatous formations,
resulted from chronic inflammatory response, appeared in the
parenchyma of the spleen and kidney as well (Fig. 1D).
The lymphocystis hypertrophied cell, was surrounded by a thick
smooth hyaline capsule. The nucleus of lymphocystis cell was
enlarged, irregular and contained basophilic marginated chromatin.
Abundant basophilic intracytoplasmic inclusion bodies, mainly in the
peripheral area of cell, were characterized in hypertrophied cell
(Fig. 1C). The cytoplasm was stained unevenly in color by hematox
hematoxylin
and eosin. The senile lymphocystis cells became an irregular and
broken hyaline capsule. Their nuclei disappeared and their cytoplasms
were released partly or totally.