RESUMEN
Rhabdomyosarcoma is a malignant tumor originating from rhabdomyoblasts that is rarely reported in domestic animals or in free-living and pet birds. This paper presents a case of rhabdomyosarcoma in a free-ranging yellow-headed caracara (Milvago chimachima), originating from the muscle region of proximal left humerus, with metastases in the left pectoral muscles, heart, lungs, and proventriculus. The cytology was suggestive of rhabdomyosarcoma because of malignant features and cytoplasmic cross-striations in cells. The histopathologic examination revealed neoplastic proliferation composed of spindle cells arranged in irregular sheets or bundles with marked cellular pleomorphism, moderate mitotic ratio, and multinucleated giant cells. Some neoplastic cells also presented evidence of scant cytoplasmic cross-striations visible at histologic sections stained by hematoxylin and eosin and phosphotungstic acid hematoxylin. Immunohistochemically, tumors cells were positive for desmin and negative for alpha-smooth muscle actin and S100 protein.
Asunto(s)
Enfermedades de las Aves/patología , Falconiformes , Rabdomiosarcoma/veterinaria , Animales , Resultado Fatal , Rabdomiosarcoma/patologíaRESUMEN
The objective of this study was to determine the occurrence of Sarcocystis spp. in Didelphis albiventris and D. aurita in three regions of the state of São Paulo. Ninety-eight dead Didelphis were employed in this study, among which 66 were D. aurita and 32 D. albiventris. Twenty eight living D. aurita and five D. albiventris were also analyzed. Flotation centrifugation in sucrose solution was used in the isolation of Sarcocystis spp. of the small intestine and feces. Sarcocystis spp. was found in the small intestines of 9.1% of the D. aurita (6/66); in four of them, the feces were also positives. There was no statistically significant difference between males and females (P= 0,522), or among samples that came from different regions of the state of São Paulo(P= 0,627), regarding the occurrence of Sarcocystis spp. However, there was a significant difference of positive samples harvested from captive compared to free-ranging animals (P = 0.009), and between adults and off spring (P= 0,004). Adults were more affected by the parasite than the off spring, and only free-ranging animals were positives. From the samples collected from 28 living D. aurita, Sarcocystis spp. was found in 7.1% (2/28) of them. A total of 32 D. albiventris were studied,none of which had positive tests for Sarcocystis spp. in samples of intestine of feces, and five animals live were also negative. We conclude that the occurrence of Sarcocystis spp. in D. aurita and D. albiventris inthese three regions of the state of São Paulo is low in the conditions assessed in this study
O objetivo deste estudo foi de determinar a ocorrência de Sarcocystis spp. em D. albiventris e D. aurita em três regiões do Estado de São Paulo. Para tal, utilizou-se noventa e oito Didelphis mortos, sendo 66D. aurita e 32 D. albiventris, e também 28 D. aurita e cinco D. albiventrisvivos. O método de centrífugo-flutuação em solução de sacarose foi empregado para isolamento dos oocistos/esporocistos de Sarcocystis spp. do intestino delgado e das fezes. Encontrou-se Sarcocystis spp.no intestino delgado de 9,1% dos D. aurita (6/66), sendo que quatro destes também houve positividade nas fezes. Não houve diferença estatística significativa entre machos e fêmeas positivos (P= 0,522), e entre os positivos de diferentes origens do Estado de São Paulo (P=0,627), quanto a ocorrência de Sarcocystis spp. Entretanto, houve diferença estatística significativa entre animais de vida livre e de cativeiro(P = 0.009), sendo que somente os de vida livre foram positivos.Entre adultos e filhotes positivos também houve diferença (P= 0,004),sendo os adultos mais parasitados que os filhotes. Das amostras provenientes dos 28 D. aurita vivos, encontrou-se Sarcocystis spp. em7.1% (2/28) deles. Dos 32 D. albiventris, todos foram negativos para Sarcocystis spp. nas amostras de intestino delgado e fezes. Os cincos D. albiventris vivos também foram negativos. Sendo assim, pode-se observar que a ocorrência de Sarcocystis spp. em D. aurita e D. albiventris nestas três regiões do Estado de São Paulo é baixa para estas condições analisadas
