Análise histopatológica e morfométrica do tumor de células da Granulosa de Gerbil (Meriones unguiculatus)

• Autor(a) principal: Neves, Margareth Costa
• Data de Publicação: 2005
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal Fluminense (RIUFF)
• Texto Completo: https://app.uff.br/riuff/handle/1/19700
• topic: Tumor de células granulosas; Patologia Experimental; Gerbillinae; Medicina experimental; Neoplasias de tecido gonadal; CNPQ::CIENCIAS DA SAUDE::MEDICINA

The granulosa cell tumor (GCT) is part of a group of neoplasms derived from the stromal sexual cord. These tumors originated from the ovarian mesenchyme have clinical importance, since they can synthesize great amounts of estrogens or have malignant behavior. As the gerbil GCT is a spontaneous disease in this species, the characterization of several aspects histopathology, growth, and tumor progression, development and metastasis pattern allows defining the biological behavior and its use as animal model of the disease. For so much, it is fundamental to know the mechanisms involved in the development of gerbil GCT and the aspects that determine its biological behavior. The aim of this study was to characterize the gerbil GCT an animal model of the disease through its histopathology and nuclear characteristics by morphometry, and to correlate the several characteristics with the biological behavior of the tumor. We used file material corresponding to 167 gerbil females, among virgins and reproducers, of several ages. The animals were maintained in the Animal Facility of the Experimental Pathology Section in the Department of Pathology, UFF, in the period of 1982 to 1992. After the complete necropsy, besides both ovaries, fragments of several organs were collected, fastened in formalin and processed for microscopy. The largest incidence of GCT was in the age group of 2 to 3 years, being mostly in virgin females. The ovaries were described at macroscopy as normal (with incipient GCT in the microscopy) or with developed GCT of cystic aspect, solid or mixed. The total of unilateral and bilateral tumors for the incipient and developed GCT was 71 and 96 respectively, being 13 solids, 63 cystic and 20 mixed. All the incipient tumors were smaller than 9mm, presented white-yellowish color, and the developed tumors varied in size (Qui-square p<0.01) and color. All the slides were reviewed for the histopathological study by optical microscopy, and the tumors were classified in agreement with its morphologic characteristics in incipient, cystic, solid and mixed. The microscopic characteristics of GCT, the local invasion and the presence, frequency location and the metastasis were analyzed, defining the classification of GCT in malignant or not. All the tumors were characterized by tumoral nests and cords of cubical cells; there were luteinic cells, Call-Exner bodies, pseudofollicles, incipient cysts, necrosis, and mitosis, except for these last ones in the incipient tumors. When comparing the several microscopic types of GCT, there was no significant difference for nests and strings, luteinic cells and Call-Exner bodies. Invasion was more frequent in the ovarian hilus, periovarian fat and fimbriae, being registered microscopically. The largest number of metastasis was abdominal, in the omentum, except for the mixed GCT type (p<0.01). Malignancy characteristics (invasion and/or metastasis) were present in 60 of 71 incipient tumors and in 77 of 85 cystic GCT; only one of 13 solid tumors were benign and all the 20 mixed were malignant. All the tumors with necrosis were malignant, as they also showed metastasis. Natural death happened in just four virgin females with malign GCT, 2 to 3 years old. The testosterone level was analyzed in 48 cases. The values of the testosterone level in incipient group varied between 0.06 and 4.80ng/ml and in the developed group varied between 0.16 and 13.0ng/ml (Mann-Whitney p<0.01). This tumor can be used as animal model of the disease giving opportunity of futures studies in the development of this ovarian tumor including genetic, hormonal and immune modulation, and action of antineoplasic drugs