Imunofenotipagem do linfoma canino pela técnica da imunocitoquímica (cell block).

Abstract

Canine lymphoma is one of the most frequent hematopoietic neoplasms in veterinary routine. Animals may have different clinical presentations, stage and sub-stage. Lymphoma is considered a heterogeneous disease, classified by immunophenotype and then sub-classified. Immunophenotype knowledge is important for diagnosis and prognosis. Immunophenotyping, in most cases, is done by means of immunohistochemistry (IHC), using a tissue fragment obtained from biopsy. Patients are often in poor condition to undergo surgery, so it is not always possible to obtain a tissue sample for biopsy. The search for an early, less invasive, and low-cost diagnosis has been motivated in several pathologies. A modality not yet explored in veterinary medicine is the cell block (CB), a technique that allows a re-embedding of material of cytological origin for complementary exams, including immunocytochemistry (ICQ). The objective of this study was to perform immunophenotyping of canine lymphoma through ICQ using CB technique. Fifty-four samples from dogs with different clinical presentations were used. ICQ samples were compared with IHC samples from the same tissue. ICQ from CB technique had 87.04% accuracy, and Kappa value of 0.6986 (p<0.001). In class-specific analysis, such as T, B or mixed cell classification, ICQ had high values of Kappa, accuracy, sensitivity, specificity, positive predictive value and negative predictive value. No animals of the non-T non-B immunophenotype (null) were identified. Cell block was designed for canine lymphoma immunophenotyping and to aid in diagnosis. CB can be implemented in the diagnostic routine, providing prognostic information and improving definitive diagnosis in a fast, simple, inexpensive and effective way.