Ocorrência simultânea de hemangiossarcoma e mastocitoma de grau II em cão da raça Pitbull / Simultaneous occurrence of hemangiosarcoma and grade II mast cell tumor in a Pit Bull Terrier

ABSTRACT

Background: The incidence of cutaneous neoplasms in dogs is high and quite variable. Hemangiosarcoma (HSA) and mast celltumor (MCT) are commonly diagnosed neoplasms in isolation; however, reports of concomitant occurrence in a single patientare rare. HSA is a malignant mesenchymal neoplasm of endothelial origin; the spleen is the most commonly affected organ.MCT is a common neoplasm that may affect any region of the body, without predilection for sex, although some breeds haveshown higher incidence. This report describes a case of HSA and MCT in a Pit bull terrier.Case A 5-year-old white male Pit bull was presented to the Small Animal Clinic of the Federal Rural University of Pernambucowith nodules in preputial region measuring 5.4 x 3.7 cm and an ulcerated nodule in the right lateral thoracic region measuring23.0 x 19.0 x 5.5 cm. The owner reported surgical excision of two previous nodules one year before the consultation, but neitherwere submitted for cytopathological or post-surgical histopathological examination. Two months after the procedure, the nodulesrecurred. Cytopathological examinations of preputial and lateral thoracic nodules were performed, with a suggestive diagnosisfor HSA and MCT, respectively. Due to the unfavorable prognosis and the weakness of the animal, euthanasia was elected.Necroscopic examination revealed an ideal body condition score (4/9), hypertrophy of right pre-scapular and axillary lymphnodes, red hepatization in the apical lobe of the right lung, with multiple, soft and pigmented nodules in the spleen, liver, pancreas and testis. Several tissue samples were collected, conditioned in 10% buffered formaldehyde solution, routinely processedfor histology, and stained with hematoxylin-eosin and toluidine blue. Microscopically, the lateral thoracic nodule consisted ofround cells in cordonal arrangement, with sparse basophilic and discretely granular cytoplasm...