High agreement of routine cytopathology and immunocytochemistry in canine lymphomas.

The aim of this study was to compare the concordance of immunophenotype established with routine cytopathology (slides stained with Giemsa solution) and immunocytochemistry according to CD3 and CD79 alpha immunoreactivity. The study was performed on cytological samples of 70 canine lymphomas subtyped on the basis of the updated Kiel classification system. Additionally, cytologic samples were examined immunocytochemically for the CD3 and CD79 alpha antigens presence and thus immunophenotype of neoplastic growth was confirmed. The cytopathological and immunocytochemical diagnoses were then compared; in order to measure the concordance between immunocytochemistry (IC) result and Giemsa stain result of the same sample the Cohen's kappa coefficient was calculated. On the basis of the results of immunocytochemistry of 70 cases of canine lymphoma examined 42 were recognized as B cell lymphoma and 28 as T cell lymphoma. Full accordance between the results of routine cytopathology and IC was obtained in 63 out of 70 examined dogs (90% of cases). It can be concluded that cytopathological examination of Giemsa stained smears is helpful in determining the lymphoma cells immunophenotype. Additionally, it seems that combination of routine cytopathology and immunocytochemistry in cases of canine lymphomas allows to obtain the precise diagnosis in 90% of cases, and allows to receive most important information that is necessary for planning of appropriate therapy and to determine prognosis. Finally, this routine procedure allowed to eliminate the need of collection of tissue samples during surgery or core-biopsy and thus time, cost and patient discomfort related to more complex and invasive medical procedures can be easily reduced.