Granulomas de anéis hialinos em mixoma odontogênico: um caso incomum / Hyaline ring granulomas in odontogenic myxoma: an unusual case

Os granulomas de anéis hialinos são achados histopatológicos incomuns, cuja etiopatogênese permanece incompletamente estabelecida. Na cavidade oral, estes achados microscópicos têm sido descritos em lesões extraósseas e intraósseas, com destaque para os cistos odontogênicos inflamatórios. No entanto, relatos sobre granulomas de anéis hialinos em tumores odontogênicos são escassos. Objetivo: Relatar o primeiro caso de granulomas de anéis hialinos em mixoma odontogênico, bem como, discutir a etiopatogênese e os aspectos clínico-patológicos destes achados microscópicos em tumores odontogênicos. Caso clínico: Paciente do sexo masculino, 30 anos, apresentava tumefação de consistência fibrosa, localizada no lado esquerdo do corpo de mandíbula, com aproximadamente 3,3 cm de extensão. Radiograficamente, observou- -se uma lesão osteolítica estendendo-se da distal do dente 35 até a região anterior do ramo ascendente da mandíbula. Foi realizada a biópsia incisional e o exame histopatológico revelou uma proliferação de células ovoides, fusiformes e estreladas dispostas em um estroma mixomatoso. Com base nestes achados, foi estabelecido o diagnóstico de mixoma odontogênico e o paciente foi submetido à ressecção parcial da mandíbula. O exame microscópico da peça cirúrgica, que confirmou o diagnóstico prévio de mixoma odontogênico, revelou a presença de pequenas e eventuais massas hialinas ovoides homogêneas/ fibrilares e estruturas arredondadas que circunscreviam material eosinofílico amorfo, compatíveis com granulomas de anéis hialinos. Conclusão: Os achados do presente caso revelam que, em tumores odontogênicos, os granulomas de anéis hialinos podem se apresentar como estruturas inconspícuas e, possivelmente, possuem uma origem exógena.

Hyaline ring granulomas are uncommon histopathological findings which their etiopathogenesis is still not well established. In the oral cavity, these microscopic findings have been described in extraosseous and intraosseous lesions, with emphasis in inflammatory odontogenic cysts. However, reports of hyaline ring granulomas in odontogenic tumors are scarce. Objective: To report the first case of hyaline ring granulomas in an odontogenic myxoma, as well as to discuss the etiopathogenesis and clinical-pathological aspects of these microscopic findings in odontogenic tumors. Case report: A 30-year-old male patient had a fibrous swelling in the left posterior region of the mandible with approximately 3.3 cm of extension. Radiographically, an osteolytic lesion extending from the distal region of tooth 35 to the anterior region of the ascending ramus of the mandible was observed. Incisional biopsy was performed and histopathological examination revealed a proliferation of ovoid, spindle and stellate-shaped cells within a myxomatous stroma. Based on these findings, the diagnosis of odontogenic myxoma was made and the patient underwent partial resection of the mandible. Microscopic examination of the surgical specimen, which confirmed the previous diagnosis of odontogenic myxoma, revealed the presence of small and occasional ovoid homogenous/ fibrillar hyaline masses and round structures enclosing amorphous eosinophilic material, which were compatible with hyaline ring granulomas. Conclusion: The findings of the present case reinforce that in odontogenic tumors, hyaline ring granulomas appear as inconspicuous structures and, probably have an exogenous origin.

Evaluation in vivo of biocompatibility of differents resin-modified cements for bonding orthodontic bands

ABSTRACT The focus of this study was to test the hypothesis that there would be no difference between the biocompatibility of resin-modified glass ionomer cements. Sixty male Wistar rats were selected and divided into four groups: Control Group; Crosslink Group; RMO Group and Transbond Group. The materials were inserted into rat subcutaneous tissue. After time intervals of 7, 15 and 30 days morphological analyses were performed. The histological parameters assessed were: inflammatory infiltrate intensity; reaction of multinucleated giant cells; edema; necrosis; granulation reaction; young fibroblasts and collagenization. The results obtained were statistically analyzed by the Kruskal-Wallis and Dunn test (P<0.05). After 7 days, Groups RMO and Transbond showed intense inflammatory infiltrate (P=0.004), only Group RMO presented greater expression of multinucleated giant cell reaction (P=0.003) compared with the control group. After the time intervals of 15 and 30 days, there was evidence of light/moderate inflammatory infiltrate, lower level of multinucleated giant cell reaction and thicker areas of young fibroblasts in all the groups. The hypothesis was rejected. The Crosslink cement provided good tissue response, since it demonstrated a lower level of inflammatory infiltrate and higher degree of collagenization, while RMO demonstrated the lowest level of biocompatibility.

Squamous odontogenic tumor: report of a case of unusual involvement / Tumor odontogênico escamoso: relato de um caso de envolvimento incomum

ABSTRACT The squamous odontogenic tumor (SOT) is defined as a very rare benign neoplasm, locally infiltrative and can extend to neighboring structures. This study aimed to report a case of SOT unusual involvement. A female patient, 56-year-old, smoker showed mild swelling in the chin region in the portion between the left canine and right first premolar. Axial, coronal and sagittal images showed expansive hypodense lesion in the mandibular symphysis and parasymphysis. Partial removal of the lesion was performed, which led to the diagnosis of SOT. The patient presented no recurrence during 4 years and 2 months follow-up.

RESUMO O tumor odontogênico escamoso (TOE) é definido como uma neoplasia benigna rara, localmente infiltrativa, podendo estender-se a estruturas vizinhas. Objetivou-se relatar um caso de TOE de acometimento incomum. Paciente do sexo feminino, 56 anos de idade, fumante, demonstrou leve aumento de volume na região do mento na porção compreendida entre o canino esquerdo e o primeiro pré-molar direito. Imagens axial, coronal e sagital demonstraram lesão expansiva hipodensa na sínfise e na linha média mandibular. Fez-se a remoção parcial da lesão, o que levou ao diagnóstico de TOE. A paciente não apresentou recidiva durante quatro anos e dois meses de acompanhamento.