title: Mucosa-associated lymphoid tissue lymphoma of the third eyelid conjunctiva in a dog.
abstract: A 4-year-old, neutered female Cocker Spaniel was presented to the veterinary clinic for protrusion of the left third eyelid. When the third eyelids from both eyes were everted, lobulated masses were present on the bulbar surface. The left third eyelid had a larger protrusion. There was no apparent associated ocular or systemic involvement. The tumor of left third eyelid was removed and referred for histological examination. Histologically, there were proliferations of lymphoid follicles surrounded by lymphoid cells forming a marginal zone. Those lymphoid cells occasionally infiltrated into conjunctival epithelium. A few apoptotic bodies with karyopyknotic and karyorrhexic nuclei were observed in the germinal center of lymphoid follicles. Mitotic figures were rare. On immunohistochemistry, tumor cells expressed CD79a but not CD3. A diagnosis of extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) of the third eyelid was established based on the histological and immunophenotypical features. At the 1-year follow-up, there was no evidence of recurrence of the mass at the area of excision of the left third eyelid and the remaining tumor of the right third eyelid was still a similar size. The dog still showed no significant findings, except those of the tumor, and no evidence of systemic involvement. To the authors' knowledge, this is the first reported case of MALT lymphoma of the third eyelid in a dog.
authors.affiliation: Department of Pathology, College of Veterinary Medicine, Kyungpook National University, Daegu 702-701, Korea.
authors.forename: Il-Hwa
authors.initials: IH
authors.lastname: Hong
authors.forename: Sun-Hee
authors.initials: SH
authors.lastname: Bae
authors.forename: Sang-Gwan
authors.initials: SG
authors.lastname: Lee
authors.forename: Jin-Kyu
authors.initials: JK
authors.lastname: Park
authors.forename: Ae-Ri
authors.initials: AR
authors.lastname: Ji
authors.forename: Mi-Ran
authors.initials: MR
authors.lastname: Ki
authors.forename: Seon-Young
authors.initials: SY
authors.lastname: Han
authors.forename: Eun-Mi
authors.initials: EM
authors.lastname: Lee
authors.forename: Ah-Young
authors.initials: AY
authors.lastname: Kim
authors.forename: Sang-Young
authors.initials: SY
authors.lastname: You
authors.forename: Tae-Hwan
authors.initials: TH
authors.lastname: Kim
authors.forename: Kyu-Shik
authors.initials: KS
authors.lastname: Jeong
mesh_terms: D000818:Animals; D003228:Conjunctiva / Q000473:pathology / Q000601:surgery; D003230:Conjunctival Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery / Q000662:veterinary*; D004283:Dog Diseases / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D004285:Dogs; D005143:Eyelids / Q000473:pathology / Q000601:surgery; D005260:Female; D018442:Lymphoma, B-Cell, Marginal Zone / Q000175:diagnosis / Q000473:pathology / Q000601:surgery / Q000662:veterinary*