Non Epitheliotropic B-Cell Lymphoma with Plasmablastic Differentiation vs. Cutaneous Plasmacytosis in a 12-Years-Old Beagle: Case Presentation and Clinical Review

Abstract

Cutaneous lymphoid neoplasms and cutaneous plasmacytosis are rare in the dog; in human and in veterinary medicine, these have many clinical, cytological, histological, and phenotypic similarities, and a diagnosis of certainty is not easy. The aim of this study is to describe a case of cutaneous non epitheliotropic B-cell lymphoma (CNEBL) with plasmablastic differentiation vs. multiple cutaneous plasmacytosis (CP) in a dog, since the scarce bibliographic data on these topics. A 12-year-old male Beagle dog was presented for multiple, nodular, cutaneous, and subcutaneous, indolent masses disseminated on the whole body. Cytological, histological, flow cytometric, and immunohistochemical examinations, as well as complete radiographic evaluation, echocardiography, and abdominal ultrasound were performed. Cytology, histopathology, flow cytometric, and immunohistochemical examination, performed on the skin lesions, revealed a B-cell phenotype with plasmablastic differentiation. Nevertheless, a final diagnosis could not be achieved and it was categorized as a case of borderline CNEBL with plasmablastic differentiation versus CP. The dog was treated with a COP chemotherapeutic protocol. Total remission was obtained and relapse occurred 120 days later. To our knowledge, specific markers are actually unavailable to certainly differentiate CNEBL and CP in the dog and future studies are needed to improve knowledge on these pathologies in veterinary medicine, since prognosis and therapy are different.

Case report: Suspected plasmablastic lymphoma in a dog resembling the clinical presentation in humans

“…A 5-year-old Golden Retriever was diagnosed with plasmablastic leukemia by positive immunolabeling for MUM-1/IRF-4 but negative for CD204, Iba-1, E-cadherin, CD3, CD5, CD79a, CD20, and PAX5 ( 18 ). In one dog with non-epitheliothropic plasmacytic lymphoma, the tumor cells presented positive immunoreactivity for CD79a and MUM-1/IRF-4 but negative immunoreactivity for CD20, PAX5, CD3, and Iba1 ( 12 ).…”

“…A dog with non-epitheliothropic plasmacytic lymphoma presenting multiple lesions was treated with COP (cyclophosphamide, vincristine, and prednisolone) chemotherapy (only induction phase), resulting in a disease-free interval of 120 days. Relapse was treated with the maintenance of the COP protocol with a second remission longer than 100 days ( 12 ). Gastrointestinal presentation of Mott lymphoma resulted in the survival of 3 months in a 2-year-old Dachshund treated with CHOP chemotherapy ( 14 ) but longer than 10 months in a 1-year-old Dachshund treated with surgery and COP chemotherapy ( 13 ).…”

“…In a more recent retrospective study of 203 canine multicentric lymphomas, lymphomas with plasmacytic or Mott cell differentiation corresponded to approximately 2% of all the cases, but again no PBL cases were reported ( 11 ). In the literature, there are also occasional case reports of lymphoma with plasmacytic or Mott cell differentiation with the involvement of skin ( 12 ), gastrointestinal tract and abdominal lymph nodes ( 13 , 14 ), liver and spleen ( 15 ), and multicentric lymphomas ( 16 , 17 ), including a case report with confirmed leukemia with plasmablastic differentiation ( 18 ). To the best of the authors' knowledge, previous cases of PBL with presentations similar to human PBL have never been reported.…”

Hematological ratios and indices in canine large B-cell lymphoma

“…Canine lymphoma is the most prevalent hematopoietic malignancy in dogs. This term encompasses a group of heterogeneous diseases that differ in clinical presentation, immunophenotype, and prognosis ( Valli et al ., 2013 ; Zandvliet, 2016 ; Antognoni et al ., 2021 ; Magni et al ., 2023 ). Canine Lymphoma is a correspondent to non-Hodgkin Lymphoma in humans.…”