Reproducibility of nuclear morphometry parameters from cytologic smears of canine cutaneous mast cell tumors--intra- and interobserver variability.

BACKGROUND: Qualitative and/or semiquantitative histopathologic grading has been the method of choice to predict the biologic behavior of mast cell tumors (MCT). Recently, computer-assisted nuclear morphometric analysis of histologic or cytologic specimens has been shown to correlate with histopathologic grading of MCT. However, it is still not clear what the reproducibility and variability of these computer-assisted measurements are. OBJECTIVES: The objective of this study was to estimate the intra- and interobserver variability in computer-assisted morphometric analysis of nuclear parameters in fine-needle cytologic smears of canine cutaneous MCT. MATERIALS AND METHODS: Measurements were performed by 2 observers with basic training on the recognition of neoplastic cells and operating the image analysis software. The analyses were performed twice at 6 months apart. RESULTS: No significant effects were detected for observer, time, and the interaction observer-time. CONCLUSIONS: Nuclear morphometric analysis of mast cell tumors using cytologic smears is a reproducible method for grading of MCT.

Liver iron overloading in captive muriquis (Brachyteles spp.).

BACKGROUND: Iron accumulation was investigated qualitatively and quantitatively in the liver of 15 captive Brachyteles spp. METHODS: Hepatic hemosiderosis index (HHI) was determined as the area percentage of the liver parenchyma occupied by hemosiderin and ferritin deposits, through computerized histomorphometric analysis of Prussian blue-stained histologic sections. RESULTS: All studied animals presented liver hemosiderosis, and HHI ranged from 0.2% to 41.7%. There were no significant differences in HHI between muriqui species or genders, and no correlations were detected among HHI and age, time in captivity or body mass. Iron deposits were accompanied by other hepatic disorders. CONCLUSIONS: This is the first study addressing the occurrence and consequences of iron overloading in the liver of muriquis. We propose that hemosiderosis may act as a contribute factor for the development of hepatic injuries. Further studies are advised to clarify the role of diet in the pathogenesis of hemosiderosis in these atelids.

Avaliação da proliferação celular como indicador prognóstico para mastocitomas cutâneos caninos / Evaluation of cellular proliferation as prognostic indicator for canine cutaneous mast cell tumors

Este estudo teve como objetivo avaliar o valor prognóstico de marcadores de proliferação celular em casos de mastocitomas cutâneos caninos. Vinte e três casos foram analisados quanto à expressão imuno-histoquímica de Ki67 e do Antígeno Nuclear de Proliferação Celular (PCNA), sendo subsequentemente acompanhados clinicamente. Observou-se que a expressão de Ki67 mantém relação negativa com a tradicional graduação histopatológica (p= 0,0418; p<0,05 entre os graus I e III), sendo um indicador confiável para o tempo de sobrevida pós-cirúrgica (p=0,0089). A imunoexpressão de PCNA, apesar de estar correlacionada à marcação por Ki67, não apresentou valores estatisticamente significantes na predição da mortalidade em função da doença e do tempo de sobrevida pós-cirúrgico. Os resultados obtidos confirmam que informações sobre a atividade proliferativa tumoral pela detecção imuno-histoquímica de Ki67 podem incrementar a classificação de mastocitomas cutâneos caninos quanto à malignidade.

This study evaluated the prognostic value of cell proliferation markers for canine cutaneous mast cell tumor cases. Twenty-three cases were analyzed with regard to immuno-histochemical expression of Ki67 and Proliferating Cell Nuclear Antigen (PCNA), and were clinically followed up. Ki67 expression was related to the traditional histopathological grading (p= 0.0418; p<0.05 between grades I and III), and was a reliable indicator of post-surgical survival (p=0.0089). PCNA immunoexpression did not show statistically significant values in the prediction of disease-related mortality and survival, although it is correlated to Ki67 expression. These results confirm that information about tumoral proliferative activity through Ki67 immunohistochemical detection can improve canine cutaneous mast cell tumor grading with regard to malignancy.