{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T01:23:04Z","timestamp":1760059384204,"version":"build-2065373602"},"reference-count":21,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,6,8]],"date-time":"2025-06-08T00:00:00Z","timestamp":1749340800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Veterinary Sciences"],"abstract":"<jats:p>Canine lymphoma (CL) is a heterogeneous neoplasm with varying prognoses, and Ki67 expression is a key marker for assessing tumor proliferation. This study aimed to compare Ki67 immunostaining in cytology smears (PSCS) and cell blocks (CBs) of canine lymphoma cases. Ki67 immunostaining was performed on 30 cases (26 nodal and 4 non-nodal) of CL, including B-cell, T-cell, and null-phenotype lymphomas. The Ki67 index was quantified manually using image analysis software as a support. The results showed Ki67 positivity in all CBs, with archival time affecting the antigenicity in PSCS, especially in samples older than two years. The Ki67 index in CBs of nodal CL were higher, and there was no significant agreement on Ki67 classification in PSCS and CBs. A univariate brief survival analysis was performed to preliminary evaluate the prognostic value of Ki67 in cytological samples. Ki67 indexes determined in cytology showed no significant association with survival. Cases of nodal CL with high Ki67 in CBs, if treated with chemotherapy, tended to survived longer (compared to those animals not treated with chemotherapy). These preliminary results showed that Ki67 immunostaining in CBs is more reliable for assessing CL proliferation and might offer predictive information. These findings highlight the potential of Ki67 quantification in CBs for supporting treatment decisions.<\/jats:p>","DOI":"10.3390\/vetsci12060561","type":"journal-article","created":{"date-parts":[[2025,6,9]],"date-time":"2025-06-09T06:46:01Z","timestamp":1749451561000},"page":"561","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Proliferation in Minimal Invasive Samples of Canine Lymphomas: Ki67 Index in Previously Stained Cytology and Paired Cell Blocks"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0206-6903","authenticated-orcid":false,"given":"Filipe","family":"Sampaio","sequence":"first","affiliation":[{"name":"Cytology and Hematology Diagnostic Services, Laboratory of Histology and Embryology, Department of Microscopy, ICBAS\u2013School of Medicine and Biomedical Sciences, University of Porto (U.Porto), Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"},{"name":"CEDIVET\u2014Laborat\u00f3rio Cl\u00ednico Veterin\u00e1rio, 4465-671 Le\u00e7a do Balio, Portugal"}]},{"given":"Carla","family":"Marrinhas","sequence":"additional","affiliation":[{"name":"Cytology and Hematology Diagnostic Services, Laboratory of Histology and Embryology, Department of Microscopy, ICBAS\u2013School of Medicine and Biomedical Sciences, University of Porto (U.Porto), Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"},{"name":"Hospital do Baixo Vouga, OneVet Group, 3750-742 \u00c1gueda, Portugal"}]},{"given":"Lu\u00edsa","family":"Fonte-Oliveira","sequence":"additional","affiliation":[{"name":"Cytology and Hematology Diagnostic Services, Laboratory of Histology and Embryology, Department of Microscopy, ICBAS\u2013School of Medicine and Biomedical Sciences, University of Porto (U.Porto), Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"},{"name":"Anicura CHV Porto, 4100-320 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5502-5991","authenticated-orcid":false,"given":"Ricardo","family":"Marcos","sequence":"additional","affiliation":[{"name":"Cytology and Hematology Diagnostic Services, Laboratory of Histology and Embryology, Department of Microscopy, ICBAS\u2013School of Medicine and Biomedical Sciences, University of Porto (U.Porto), Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2470-0795","authenticated-orcid":false,"given":"Pedro N.","family":"Oliveira","sequence":"additional","affiliation":[{"name":"Department of Population Studies, ICBAS, University of Porto, 4050-313 Porto, Portugal"},{"name":"EPIUnit, ITR\u2014Laboratory for Integrative and Translational Research in Population Health, University of Porto, 4050-600 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1350-4254","authenticated-orcid":false,"given":"Marta","family":"Santos","sequence":"additional","affiliation":[{"name":"Cytology and Hematology Diagnostic Services, Laboratory of Histology and Embryology, Department of Microscopy, ICBAS\u2013School of Medicine and Biomedical Sciences, University of Porto (U.Porto), Rua de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal"},{"name":"Oncology Research, UMIB\u2014Unit for Multidisciplinary Research in Biomedicine, ICBAS, University of Porto, 4050-313 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"198","DOI":"10.1177\/0300985810379428","article-title":"Classification of canine malignant lymphomas according to the World Health Organization criteria","volume":"48","author":"Valli","year":"2011","journal-title":"Vet. 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