title: Characterization of spontaneous malignant lymphomas in Japanese macaques (Macaca fuscata).
abstract: Lymphomas are common spontaneous tumors in nonhuman primates but remain poorly characterized in Japanese macaques (Macaca fuscata). This study examined 5 cases of spontaneous malignant lymphoma in Japanese macaques, focusing on the immunophenotypes and presence of simian lymphocryptoviruses, which are Epstein-Barr virus-related herpesviruses in nonhuman primates. The macaques with lymphoma were 5 to 28 years old, indicating that lymphomas develop over a wide age range. The common macroscopic findings were splenomegaly and enlargement of lymph nodes. Histologic and immunohistochemical analyses revealed that all cases were non-Hodgkin type and exhibited a T-cell phenotype, positive for CD3 but negative for CD20 and CD79α. The lymphomas exhibited diverse cellular morphologies and were subdivided into 3 types according to the World Health Organization classification. These included 3 cases of peripheral T-cell lymphoma, not otherwise specified; 1 case of T-cell prolymphocytic leukemia; and 1 case of an unclassifiable T-cell lymphoma. Positive signals were detected by in situ hybridization in 2 of the 4 examined cases using probes for the Epstein-Barr virus-encoded small RNA (EBER). Furthermore, the presence of M. fuscata lymphocryptovirus 2, a macaque homolog of Epstein-Barr virus, was demonstrated in EBER-positive cases by polymerase chain reaction amplification followed by direct sequencing. Immunohistochemistry using antibody to the Epstein-Barr virus-encoded nuclear antigen 2 was negative, even in the EBER-positive cases. The present study suggests that T-cell lymphoma is more common than B-cell lymphoma in Japanese macaques and that M. fuscata lymphocryptovirus 2 is present in some cases.
authors.affiliation: Division of Animal Experiment, Life Science Research Center, Gifu University, Gifu City, Gifu, Japan akatsuki@gifu-u.ac.jp.
authors.forename: A
authors.initials: A
authors.lastname: Hirata
authors.affiliation: Laboratory of Veterinary Pathology, Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu City, Gifu, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Hashimoto
authors.affiliation: Laboratory of Veterinary Pathology, Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu City, Gifu, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Katoh
authors.affiliation: Laboratory of Veterinary Pathology, Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu City, Gifu, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Sakai
authors.affiliation: Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA.
authors.forename: A G
authors.initials: AG
authors.lastname: Bruce
authors.affiliation: Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, WA, USA.
authors.forename: T M
authors.initials: TM
authors.lastname: Rose
authors.affiliation: Center for Human Evolution Modeling Research, Primate Research Institute, Kyoto University, Inuyama City, Aichi, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kaneko
authors.affiliation: Center for Human Evolution Modeling Research, Primate Research Institute, Kyoto University, Inuyama City, Aichi, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Suzuki
authors.affiliation: Division of Animal Experiment, Life Science Research Center, Gifu University, Gifu City, Gifu, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Nikami
authors.affiliation: Laboratory of Veterinary Pathology, Department of Veterinary Medicine, Faculty of Applied Biological Sciences, Gifu University, Gifu City, Gifu, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Yanai
mesh_terms: D000818:Animals; D005260:Female; D006566:Herpesviridae Infections / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary; D017403:In Situ Hybridization / Q000662:veterinary; D015461:Leukemia, Prolymphocytic, T-Cell / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary / Q000821:virology; D008198:Lymph Nodes / Q000473:pathology; D018143:Lymphocryptovirus; D008223:Lymphoma / Q000150:complications / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D016399:Lymphoma, T-Cell / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary / Q000821:virology; D016411:Lymphoma, T-Cell, Peripheral / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary / Q000821:virology; D008251:Macaca; D008297:Male; D008992:Monkey Diseases / Q000175:diagnosis / Q000473:pathology* / Q000821:virology; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D013163:Splenomegaly / Q000209:etiology / Q000473:pathology / Q000662:veterinary; D014412:Tumor Virus Infections / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary / Q000821:virology
keywords: Epstein-Barr virus; Japanese macaque; T cell; lymphocryptovirus; lymphoma