A Retrospective Study of Those Histopathologic Parameters Predictive of Invasion of the Lymphatic System by Canine Mammary Carcinomas

Abstract

The aim of the present study was to determine which histopathologic parameters of primary canine mammary carcinomas (CMCs) could predict metastatic spread via the lymphatic system. A modification of the World Health Organization classification was applied to 245 CMCs. In addition to tumor subtype, neoplastic infiltration of the surrounding mammary stroma, vasculogenic mimicry, and micropapillary pattern were evaluated, and 2 histologic grading systems were used for each sample. A statistical analysis was undertaken to determine the relationship between these histopathologic parameters and the detection of lymphatic vessels invasion (LVI) and regional lymph node metastases (RLM). To compare the predictive value for lymphatic spread of the 2 histologic grading systems, the Akaike information criterion was measured. The classification into tumor subtypes was significant (P < .01) in predicting the risk of LVI and RLM. Peripheral infiltration, vasculogenic mimicry, and micropapillary pattern were found in 170 of 245 (69.4%), 32 of 245 (13.1%), and 54 of 245 (22.0%) CMCs. The presence of peripheral infiltration was significantly associated (P < .001) with both LVI and RLM, and a similar relation (P < .05) was found for the micropapillary pattern. Vasculogenic mimicry was not predictive of invasion of the lymphatic system. Both histologic grading systems were significant predictors (P < .001) of the risk of LVI and RLM. The grading system that included a more rigorous evaluation of the neoplastic mitotic activity had the lower Akaike information criterion values, thus indicating a better predictive ability. The study confirms the significant prognostic role for the modified World Health Organization classification of CMCs and the prognostic value of additional histopathologic parameters.

Prognostic Value of Histological Grading in Noninflammatory Canine Mammary Carcinomas in a Prospective Study With Two-Year Follow-Up

“…13 A retrospective study comparing both the Misdorp and Peña grading systems on a large series of canine malignant mammary neoplasms was recently published. 30 This previous study showed that both histological grading systems are significant predictors (P < .001) of the risk of lymphatic vessel invasion and regional lymph node metastases at the time of diagnosis. However, the Peña system (partially published as Clemente et al 3 ) has been shown to have a better predictive ability.…”

Metástase De Carcinoma Mamário Em Sistema Nervoso Central De Cadela

“…No presente relato, o carcinoma tubular, desde o primeiro diagnóstico já apresentava características de malignidade, como a metástase em linfonodo inguinal. Rasotto et al (2012) verificaram que 60% dos carcinomas tubulares apresentaram invasão linfática e 27% metástase em linfonodos.…”

“…De acordo com Rasotto et al (2012) os carcinomas tubulares são mais frequentemente do tipo II (62%). Carcinomas tubulares grau II apresentam invasão linfovascular em 71% dos casos e metástase para os linfonodos em 31% dos casos.…”

Emboles lymphatiques des carcinomes mammaires invasifs félins : amélioration de leur détection par immunohistochimie et valeur pronostique

“…Chez la chienne, la fréquence de l'embolisation lymphatique varie aussi selon les auteurs : elle est de 25% dans une cohorte de 84 cas (De Las Mulas et al 2005) et de 38% parmi 29 cas rapportés par Millanta et al (2006), elle atteint 55% sur 102 cas (Gama et al 2008) et 78% dans une cohorte de 245 cas (Rasotto et al 2012). Dans une cohorte rétrospective des 350 carcinomes mammaires invasifs canins de notre Unité de recherches, la fréquence de l'embolisation lymphatique déterminée par HES est de 49% (171/350), c'est-à-dire une fréquence similaire à celle observée chez la chatte (communication personnelle).…”