Medycyna Wet. 64 (7), 872-876, 2008
Sapierzyński R., Sokołowska J |
Cytological diagnosis of canine lymphomas |
Malignant lymphomas (ML), actually lymphomas, are common tumors in dogs, outnumbered only by mammary and cutaneous tumors. The existing morphological classifications of canine ML have been based successively on different human classifications, including Rappaport, the Working Formulation and the Kiel classification. The behavior of canine malignant lymphomas is difficult to predict on the basis of histomorphology alone, and thus other advanced techniques are needed in the establishment of prognostic factors. Evaluation of tumors phenotype (B cell and T cells), proliferation rate (mitotic index, Ki67 expression, AgNORs number) in histologic sections is possible and often enables a precise diagnosis. Fine-needle aspiration cytology remains the first line of investigation (screening test) used in all cases of mono- or polylymphadenopathy. It helps to obtain initial diagnosis (lymphoma, metastases, hyperplasia), in staging the disease, in the detection of the recurrence and progression of the neoplastic process. Lymphomas have successfully been classified by FNA cytology, in human medicine the success rate of this procedure ranges from 80 % to 90 % in the diagnosis of malignant lymphoma and 67.5 % to 86 % in its subtyping. Cytology is a safer, cheaper, and more rapid procedure than histology, and the owner often disagrees to the surgical procedure essential to obtaining tissue samples. Immonophenotyping, can be successfully established in aspiration biopsy samples of enlarged lymph nodes in dogs with lymphoma. Moreover, the evaluation of the proliferation rate of neoplastic cells by immunocytochemy or other cytopathologic stains can also be made. |
Keywords: canine lymphoma, fine needle biopsy, cytopatology, diagnosis |