title: Extra-nodal subcutaneous Hodgkin's-like lymphoma and subsequent regression in a cat.
abstract: Hodgkin's-like lymphoma is a slow growing neoplasm, usually affecting the lymph nodes of the head and neck, which has been sporadically described in veterinary patients. This report describes the clinical and histopathological features in a 9-year-old male neutered Siamese cat that presented with a 6 week history of mid-dorsocranial swelling. Immunohistochemistry demonstrated positive staining for CD79a, paired box protein and B lymphocyte antigen-36, with variable, weak-to-moderate cytoplasmic staining for human leukocyte antigen-DR and CD18, and negative staining for antimacrophage antibody. The diagnosis based on incisional biopsy was Hodgkin's-like lymphoma; however, no evidence of neoplasia was found following wide surgical excision. This case report demonstrates two unreported items of note: the novel extranodal site of Hodgkin's-like lymphoma in a cat and tumour regression following initial biopsy. It is hypothesised that the surgical trauma of biopsying the lesion or the introduction of foreign material may have caused the regression of the neoplastic cells through induction of an anti-tumour immune or inflammatory response.
authors.affiliation: School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
authors.forename: Jamie A
authors.initials: JA
authors.lastname: Newton
authors.affiliation: School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK felipe.devicente@glasgow.ac.uk.
authors.forename: Felipe
authors.initials: F
authors.lastname: de Vicente
authors.affiliation: Bridge Pathology Ltd, Bristol, UK.
authors.forename: Sean P
authors.initials: SP
authors.lastname: Haugland
authors.affiliation: Bridge Pathology Ltd, Bristol, UK.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Scase
authors.affiliation: School of Veterinary Medicine, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
authors.forename: Jenny
authors.initials: J
authors.lastname: Helm
mesh_terms: D000818:Animals; D002371:Cat Diseases / Q000473:pathology* / Q000601:surgery*; D002415:Cats; D003937:Diagnosis, Differential; D006257:Head; D007150:Immunohistochemistry / Q000662:veterinary; D008228:Lymphoma, Non-Hodgkin / Q000473:pathology / Q000662:veterinary*; D008297:Male; D009333:Neck; D009365:Neoplasm Regression, Spontaneous; D012878:Skin Neoplasms / Q000473:pathology / Q000662:veterinary*