First Report of Epidermal Inclusion Cyst in Cyprinus carpio

Increasing reports have emerged on fish diseases resulting from a variety of pathogens. Here, a case of epidermal inclusion cyst (EIC) is reported in a sample of Cyprinuscarpio obtained from a small pond in Iran. The cyst occurred on the caudal fin projecting from the skin. Microscopic observationsdisclosed a fibrous wall consisted mostly of one cell layer but of two or three squamous cell layers at some regions. The cyst pierced deep into the internal space containing a transparent and colorless fluid. Although EIC is rather common in human but this is apparently the first report of EIC incidence in common carp.