Morphologic spectrum, immunohistochemical characterization and prognosis of the canine haemangiopericytoma / Classificação morfológica, imunoistoquímica e prognóstica dos hemangiopericitomas caninos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

Haemangiopericytomas CHP like Schwanomas are cutaneous neoplasms of mesenchymal origin, frequently appearing in dogs, unlike neurofibromas, which are rare on the species. There are cases reported that CHP originates from pericytes, or cells located around blood vessels. They are observed more in limbs such as tissues, they are well defined, big and firm. Haemangiopericytomas have histologic characteristics common to schwanomas (neurofibromas), suggesting a possible similarity in histogenesis. In fact, at this service of Animal Pathology experience, the distinguishing final diagnosis between Haemangiopericytomas and neurofibromas, based only on morphology offers great difficulty. The hispathological aspects of the haemangiopericytons and of the schwanomas correspond to the presence or not (respectively) of spiral pericilar shape cell forms. Attempting to better identify and distinguish the haemangiopericytons from other mesenquimal tumors, mainly neurofiberns, the study indicates the histological, epidemiological and immunohistochemical characterization of Haemangiopericytomas in canine species. With this, it is expected to refine the distinguishing diagnosis of such tumors, for they are known to be neoplasms rarely and wrongly diagnosed due to difficulties to identify them morphologically. The work also studies cell proliferation at the three histological subtypes of CHP and the count for morphological malignity, correlating with the clinic prospect. In order to accomplish it, the work proposes a thoroughly case study of Haemangiopericytomas and neurofibromas and/or neurobrosarcomas in dogs; investigating on the archives of the Necrology Department of Pathology at the Veterinary Medical and Zoology at São Paulo University; from 1990 to 2003, to reclassify histologically these neoplasms and scale the subtypes of CHP. The results indicated a sum of 77 cases of CHP from which the subtype perivascular accounted for (35/77) cases; the storiform (20/77) and the epithelioid (22/77). The conclusions of immunohistochemical to perivascular type (HPV) reveal positiveness of 100% to F8; 60% to S100; 100% to vimentin; 7% to GFAP and 0% to CD34 and cytokeratin. The type estoriform (HES) revealed 70% positiveness to F8; 50% to S100; 100% to vimentin; 0% to cytokeratin and GFAP; 10% to CD34. Note that to epithelioid (HEP) 70% positiveness to F8; 40% to S100; 90% to vimentin; 0% to cytokeratin; GFAP and CD34. Statistical count of malignity criteria such as PCNA (CL3); miotic level (CL1); apoptotic level (CL4); multinucleous cells (CLO) reveal on subsequent (HPV, HE, HEP) subtypes of CHP, respectively: CLO (6.135 (6.135±4.038; 5.067±3.019; 11.217±5.729); CL1 (6.155±2.380; 7.545±1.941; 12.540±8.629); CL3 (30.042±10.824; 39.1.22±11.158; 41.945±9.705); CL4 (1.153±1.1443; 1.888±1.988; 2.400±1.648). The clinical prognostic revealed 59% receding rate to epithelioid. Therefore the study showed that Haemangiopericytomas must be histologically scaled by three subtypes of which the epithelioid appears to be the most AGGRESSIVE =INVASIVE) and perivascular the most incidental (45,5%) (35/77cases); immunohistochemical may have an important role on distinguishing between Haemangiopericytomas and neurofibrossarcomas due to positiveness and negativeness of Factor 8 respectively; notwithstanding it does not aid to distinguish between subtypes from CHP. Nevertheless, a criteria definition that enables to distinguish, scale and define CHP may have relevant epidemiologic, therapeutical and prognostical connotations as shown by the present study

ASSUNTO(S)

graduação histológica imunoistoquímica morfologia morphology hemangiopericitoma pericito prognostic dogs mythosis schwanoma haemangiopericytomas immunohistochemical pcna neurofibroma célula de schwann histological scale pericytes apoptosis cães mitose schwanoma cell schwanoma apoptose neurofibroma pcna prognóstico

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