Thaís Dos Santos Fontes Pereira1, Bruno Augusto Benevenuto de Andrade2, Mário José Romañach2, Núbia Braga Pereira3, Carolina Cavalieri Gomes3, Bruno Augusto Linhares Almeida Mariz4, Oslei Paes de Almeida4, Michelle Agostini2, Willie F P van Heerden5, Roman Carlos6, Ricardo Santiago Gomez1, Felipe Paiva Fonseca7. 1. Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil. 2. Department of Oral Diagnosis and Pathology, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. 3. Department of Pathology, Biological Sciences Institute, Universidade Federal de Minas Gerais., Belo Horizonte, Minas Gerais, Brazil. 4. Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Piracicaba, Brazil. 5. Department of Oral Pathology and Oral Biology, School of Dentistry, University of Pretoria, Pretoria, South Africa. 6. Pathology Division, Centro Clínico de Cabeza y Cuello/Hospital Herrera Llerandi, Guatemala City, Guatemala. 7. Department of Oral Surgery and Pathology, School of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil; Department of Oral Pathology and Oral Biology, School of Dentistry, University of Pretoria, Pretoria, South Africa. Electronic address: Felipepfonseca@hotmail.com.
Abstract
OBJECTIVE: The aim of this study was to describe the clinicopathologic features of a series of gnathic epithelioid osteoblastomas. As high levels of Proto-oncogene c-Fos proteins resulting from FOS-FOSB translocation were recently demonstrated in osteoblastomas, we also evaluated the immunoexpression of these proteins. STUDY DESIGN: Records of all cases of epithelioid osteoblastoma of the jaws were retrieved from oral pathology services, and their clinicopathologic and immunohistochemical data were collected. Immunohistochemistry was also performed by using anti-FOS and anti-FOSB antibodies. RESULTS: Six cases of epithelioid osteoblastomas were obtained, 4 in men and 2 in women, and they were mainly located in the posterior body of the mandible (n = 4). Radiographically, the tumors showed mixed radiolucent and radiopaque images, most with poorly defined margins. Microscopically, large epithelioid cells with eccentrically located nuclei predominated among osteoid and immature bone trabeculae. Sharp delineation from adjacent normal bone was observed in all cases. FOS immunostaining was diffuse and strong in the cytoplasm and nucleus of neoplastic cells in all cases, whereas FOSB was only focally positive, with few epithelioid osteoblasts showing nuclear staining. CONCLUSIONS: Although epithelioid osteoblastomas of the jaws are locally aggressive, widespread metastasis does not occur, and, as with conventional osteoblastomas, there is wide expression of the FOS protein.
OBJECTIVE: The aim of this study was to describe the clinicopathologic features of a series of gnathic epithelioid osteoblastomas. As high levels of Proto-oncogene c-Fos proteins resulting from FOS-FOSB translocation were recently demonstrated in osteoblastomas, we also evaluated the immunoexpression of these proteins. STUDY DESIGN: Records of all cases of epithelioid osteoblastoma of the jaws were retrieved from oral pathology services, and their clinicopathologic and immunohistochemical data were collected. Immunohistochemistry was also performed by using anti-FOS and anti-FOSB antibodies. RESULTS: Six cases of epithelioid osteoblastomas were obtained, 4 in men and 2 in women, and they were mainly located in the posterior body of the mandible (n = 4). Radiographically, the tumors showed mixed radiolucent and radiopaque images, most with poorly defined margins. Microscopically, large epithelioid cells with eccentrically located nuclei predominated among osteoid and immature bone trabeculae. Sharp delineation from adjacent normal bone was observed in all cases. FOS immunostaining was diffuse and strong in the cytoplasm and nucleus of neoplastic cells in all cases, whereas FOSB was only focally positive, with few epithelioid osteoblasts showing nuclear staining. CONCLUSIONS: Although epithelioid osteoblastomas of the jaws are locally aggressive, widespread metastasis does not occur, and, as with conventional osteoblastomas, there is wide expression of the FOS protein.
Authors: Baptiste Ameline; Michaela Nathrath; Karolin H Nord; Felix Haglund de Flon; Judith V M G Bovée; Andreas H Krieg; Sylvia Höller; Jürgen Hench; Daniel Baumhoer Journal: Mod Pathol Date: 2022-03-28 Impact factor: 8.209