Thirty-eight cases of canine leproid granuloma were diagnosed between 2000 and 2008. Diagnosis was based upon clinical and histopathological findings and the presence of acid-fast bacilli in skin sections. The clinical lesions were localized predominantly on the pinnae and included papules, plaques and nodules, with or without ulceration. Boxer dogs were the breed most affected. Histopathological findings included nodular to diffuse pyogranulomatous, lymphoplasmocytic inflammatory infiltrates, with or without necrosis, localized in the dermis or subcutaneous tissue. The bacillary loading and morphology were variable among the lesions analysed. There was no significant correlation between bacterial load and histopathological pattern, dominant type of inflammatory infiltration or the amount of necrosis or giant cells. No correlation was observed between giant cells and histopathological pattern. In the majority of cases where a PCR-based assay was done, a novel mycobacterium species as the main aetiological agent was identified, as reported in previous studies.

RESUMOO carcinoma de células escamosas (CCE) é uma neoplasia epitelial maligna que acomete cães e diversas outras espécies, incluindo a humana. O CCE afeta vários sítios anatômicos e pode desenvolver metástase. O objetivo deste estudo foi a caracterização das fibras de colágenos tipos I e III no estroma do CCE cutâneo de cães. Para este trabalho, utilizaram-se 44 amostras de pele incluídas em parafina e que tiveram prévio diagnóstico de CCE. As amostras foram processadas histologicamente e coradas com hematoxilina/eosina para confirmação do diagnóstico e classificação do grau de diferenciação tumoral e com a coloração histoquímica de picrosirius para observação dos colágenos tipos I e III. O colágeno tipo III mostrou maior expressão nos CCEs cutâneos bem diferenciados. O papel do colágeno do tipo III nas neoplasias não está bem esclarecido, e outros fatores além do grau de diferenciação celular podem estar envolvidos em sua expressão e determinar sua importância na biologia tumoral. A matriz extracelular (MEC) é principalmente composta por duas classes de macromoléculas: proteínas fibrosas (incluindo colágenos e elastina) e glicoproteínas (incluindo fibronectina, proteoglicanos e laminina) (Mouw et al., 2014). O colágeno é a proteína mais comum no reino Recebido em 31 de maio de 2015 Aceito em 16 de setembro de 2015 E-mail: adriana.ortiz.bedoya@gmail.com animal, constituindo o arcabouço extracelular para todos os organismos multicelulares, e desempenha importantes funções estruturais e morfogênicas em matrizes e membranas basais em muitos tecidos e órgãos (Iwasaki et al., 2012). Na derme, o colágeno é um componente importante e desempenha um papel-chave na resistência e elasticidade da pele (Verhaegen et al., 2012). As fibras colágenas representam 90% http://dx

Fibroadnexal hamartoma (FH), also called focal adnexal dysplasia, is the most common hamartomatous lesion in dogs. There are few retrospective studies about FH in dogs, which did not describe histopathological findings in detail. The main objective was to conduct a retrospective study and to describe the epidemiological and histopathological characteristics of a series of 102 FH cases in dogs. Descriptive statistics and Odds Ratio were used to analyze the data. The lesions were exophytic and measured on average 2.5 cm in diameter. The anatomic sites most affected were the limbs and digital region. The animals were on average 7 years of age and both sexes were equally affected. Doberman (OR: 4.15; P=0.0069) and Schnauzer (OR: 2.50; P=0.049) showed a higher risk for FH. Recurrence was not observed in any case. Four histopathological FH subtypes were identified: follicle-sebaceous (73.53%), sebaceous (16.66%), follicular (8.82%) and sebaceous-apocrine (0.98%). Diffuse and perianexial fibroplasia and inflammation were frequently seen. Chronic inflammation and mature adipocytes were seen in 71.6% and 7.8% of the cases, respectively.

In a period of eight years, nevic lesions were diagnosed in 81 cases. Fibroadnexal hamartoma (FH) occurred in 53 animals (65.4%), and it was clinically characterized by

Soft tissue sarcomas (STS) comprise a heterogeneous group of malignancies derived from extra-skeletal mesenchymal tissues that may show similar histopathological changes. Histopathologic patterns suggestive of perivascular wall tumors (PWT) and peripheral nerve sheath tumors (PNST) have been described. This study investigated the histogenesis in a series of 71 cases of canine STS that showed morphological compatibility with what is described for PWT and PNST. Immunohistochemistry analysis were done to CD56, S100, SMA, Desmin, Von Willebrand Factor, NSE and GFAP. Twenty-one cases (29.6%) showed histopathologic features compatible with PWT, 23 cases (32.4%) with PNST and 27 cases (38.0%) shared both histopathological features. By immunohistochemistry, 59 (83.1%) cases showed positivity only for neural markers and 12 (16.9%) had simultaneous positivity for both neural and muscle markers. PNST was the most prevalent neoplasm and none of the cases were positive for muscle markers only. The histopathologic features were not useful to define the diagnosis of PWT, since most tumors were negative for muscle markers but positive for neural markers. Due to this immunoreactivity and the morphologic features, future studies may propose guidelines for the classification of these neoplasms.