title: An internal X-cell pseudotumor in a black croaker (Cheilotrema saturnum).
abstract: Cells closely resembling X-cells were the primary cellular component of a large pseudotumor in the viscera of a black croaker (Cheilotrema saturnum). The fish was captured in coastal waters off San Diego, California and was maintained at the Scripps Aquarium. After 2 years in captivity the fish exhibited extreme abdominal swelling due to a visceral mass, which weighed approximately one-fifth the total body weight. The cells associated with the pseudotumor were identified as X-cells due to their great variability in size, vesicular nuclei which stained negative for DNA and their formation of a pseudotumor. This is the first report of an X-cell pseudotumor in the visceral cavity. We agree with the hypothesis that the X-cell is a protozoan, and the description here of X-cells in a visceral pseudotumor in a fish of the family Sciaenidae associates an additional type of lesion with this enigmatic parasite.
authors.affiliation: Battelle Marine Research Laboratory, Sequim, Washington 98382.
authors.forename: M L
authors.initials: ML
authors.lastname: Kent
authors.forename: M S
authors.initials: MS
authors.lastname: Myers
authors.forename: S R
authors.initials: SR
authors.lastname: Wellings
authors.forename: R A
authors.initials: RA
authors.lastname: Elston
mesh_terms: D000008:Abdominal Neoplasms / Q000473:pathology / Q000662:veterinary; D000818:Animals; D005393:Fish Diseases / Q000473:pathology*; D010473:Perciformes; D011528:Protozoan Infections / Q000473:pathology; D011529:Protozoan Infections, Animal