title: Diagnostic exercise: ascites, abdominal masses, and diffuse peritoneal nodules in a rat.
abstract: A 1.4-year-old virgin female brown-hooded fancy rat presented for abdominal distention, jaundice, and dyspnea. At physical examination, a firm mass was palpable in the caudoventral abdomen as well as multiple small nodular masses associated with the abdominal viscera. At necropsy, in addition to a large mass replacing the left ovary and myriad nodules studding the peritoneal surface, there was 31 ml of abdominal effusion. By cytology, the abdominal fluid contained numerous pleomorphic vacuolated tumor cells surrounding globular pale eosinophilic to amphophilic acellular material that was strongly periodic acid-Schiff positive. Histologically, the tumor was biphasic with abundant acellular hyaline matrix that was also periodic acid-Schiff positive.
authors.affiliation: Department of Comparative Medicine, H054, Penn State Milton S. Hershey Medical Center, College of Medicine, 500 University Dr, Hershey, PA 17033, USA. Email: tcooper@hmc.psu.edu.
authors.forename: T K
authors.initials: TK
authors.lastname: Cooper
authors.forename: P R
authors.initials: PR
authors.lastname: Dumpala
authors.forename: T L
authors.initials: TL
authors.lastname: Whitcomb
mesh_terms: D000818:Animals; D000830:Animals, Laboratory; D001201:Ascites / Q000473:pathology / Q000662:veterinary; D003584:Cytological Techniques / Q000662:veterinary; D003937:Diagnosis, Differential; D004417:Dyspnea / Q000473:pathology / Q000662:veterinary; D018240:Endodermal Sinus Tumor / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D017809:Fatal Outcome; D005260:Female; D010051:Ovarian Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D051381:Rats; D012376:Rodent Diseases / Q000175:diagnosis* / Q000473:pathology*; D014781:Viscera / Q000473:pathology
keywords: ovary; rat; yolk sac carcinoma