Cytodiagnostics of canine lymphomas – possibilities and limitations

Abstract

Malignant lymphomas are one of the most common malignant tumours occurring in dogs. The basic method of lymphoma diagnosis in human, as well as in canine oncology is histopathology supported by immunohistochemistry. It was suggested that in veterinary medicine excisional biopsy of lymph node and histopathology should be considered only where the cytologic diagnosis is equivocal or needs to be confirmed. There are at least three basic reasons for which cytological examination ought to be accepted as a sufficient and reliable diagnostic method for lymphoma in dogs. Firstly, most dog owners consider the fine-needle biopsy as an acceptable non-harmful method of sample collection. Secondly, an increasing number of studies recommend cytology as an accurate test for diagnosing and subtyping canine lymphoma. Finally, the vast majority of canine lymphoma subtypes belong to 4-5 categories characterized by a typical cytological picture. Immunocytochemical staining of cytological smears gives new diagnostic possibilities, such as detection of markers better characterizing given growth or a potential goal for target therapy in individual cases (for example inhibitors of platelet-derived growth factor).

Immunocytochemical study of canine lymphomas and its correlation with exposure to tobacco smoke

“…Since lymphomas are a wide group of hematopoietic neoplasms with a broad range of potential outcomes [ 2 , 7 , 16 ], the simple diagnosis of “lymphoma” is of limited value for the clinical management of patients or even for the conduction of epidemiological studies. ICC plays a unique role in the improvement of the cytological diagnosis of canine lymphoma.…”

“…MI and Ki67 immunolabeling are the proliferation parameters more commonly used in veterinary oncology [ 7 ]. Counting the number of mitotic figures in cytological preparations can be misleading and lacks representativeness, mainly due to an irregular cell distribution [ 7 ].…”

“…According to our experience, more than 70% of lymphoma diagnoses in dogs are achieved through cytology (unpublished data). Arecent publication [ 7 ] calculated that 90% of all canine lymphoma diagnoses were obtained using cytology. Although immunocytochemistry (ICC) [ 8 ] was studied in the past decades, it has not been routinely included in the diagnostic approach of canine lymphomas [ 9 , 10 ].…”

Linfoma imunoblástico em cão

“…Baseando-se nas classificações de Kiel (Lennert e Feller, 1990) O diagnóstico diferencial de linfoma imunoblástico deve ser realizado com a hiperplasia imunoblástica caracterizada pela predominância de grandes imunoblastos nos aspirados, entretanto na hiperplasia imunoblástica o processo é geralmente transitório, enquanto que no caso do linfoma imunoblástico não há regressão (Sapierzyński et al, 2016), como observado no animal deste estudo em que se constatou a progressão da doença.…”

Study of DNA topoisomerase IIa expression in canine lymphomas and its potential role as a marker of sensitivity to anthracycline-based chemotherapy in dogs

“…The main diagnostic test for suspected lymphoma is cytopathological examination of fine needle aspirates collected from enlarged lymph nodes and, according to the WHO guidelines, histopathological examination of the surgically removed lymph node supplemented with 47 DNA topoisomerase IIα expression in canine lymphomas ©Polish Society for Histochemistry and Cytochemistry Folia Histochem Cytobiol. 2020 10.5603/FHC.a2020.0004 www.journals.viamedica.pl/folia_histochemica_cytobiologica the immunophenotype assessment [5][6][7][8]. Canine lymphomas are very sensitive to chemotherapy, as evidenced by numerous studies which indicate that complete remission (CR) is obtained in about 65% to 98% of treated animals [9][10][11][12][13][14][15][16].…”