MARCHIONNI, MIGUEL GUSTAVO SET  UBAL ANDRADE and, ANT ^ ONIO LUCINDO PINTO DE CAMPOS SOBRINHO The odontogenic myxoma is a benign odontogenic tumor, with aggressive characteristics, capable of causing many sequelae with a consequent decrease in a patient’s quality of life. The present study aims to report a clinical case of odontogenic myxoma treated by radical surgery in association with liquid nitrogen cryotherapy. A 37-year-old female patient sought dental care with complaints of increased jaw volume but was otherwise asymptomatic. Clinical examination revealed increasing in vol- ume in the vestibular-lingual region of the mandibular symphy- sis. Radiographically, an extensive multilocular radiolucent area was observed. The proposed treatment was the surgical approach of marginal block resection, with preservation of the mandibular base for bow maintenance, associated with the freezing of the region in order to minimize the risks of recurrence, due to the lack of capsule and lesion’s loose consistency. The patient is under a 1-year nonsymptomatic follow-up, without recurrence and rehabilitation with a partial, removable denture. CONSERVATIVE MANAGEMENT OF A MUL- TICYSTIC LESION OF THE ANTERIOR MAN- DIBLE: HISTOLOPATHOLOGIC ASPECTS CHANGE THE DIAGNOSIS. LOHANNA KAROLINE RODRIGUES ROSSETE, JUAN PABLO DA SILVA BARBOSA, LINDEMBERG BENTES DA SILVA, LARISSA HELENA DE OLIVEIRA RESENDE, LUCAS SILVA DAS NEVES and, TIAGO NOVAES PINHEIRO The present study aims to report a case of a cystic lesion affecting the left paramental edentulous mandible region in a 62-year-old female patient. The patient reported a 1-year growth history, and noted pain in the area during the last few months. Clinical inspection showed a multilobulated, translu- cent swelling with a well-defined cystic radiolucency aspect on imaging examination. Presurgical puncture of the lesion revealed a transparent liquid content. A cystic decompression was then performed and the obtained specimen from the roof of the lesion was submitted for histopathologic examination. The results indicated that the lesion was compatible with botryoid cyst. After 5 months, an enucleation of the lesion was per- formed. Surprisingly a new pathologic report changed the diag- nosis to multicystic ameloblastoma. We discuss the microscopic characteristics and the changes observed on the product of enucleation, as well as its clinical implications. ODONTOGENIC MYXOMA. CONSTANZA ULLOA BEQUER, MACARENA SHERMAN ALLENDORF, JUAN PABLO BRITO SANCHEZ, MAURICIO CARRASCO RODRIGUEZ, JUAN CARLOS PASTOR MORALES, ANA MAR  IA SALAZAR ROA and, PAULINA CUBILLOS GONZ  ALEZ A 19-year-old female patient was referred to the oral medi- cine clinic to evaluate an asymptomatic and unilateral swelling in the left mandibular area. The periapical radiography showed an apparently unilocular radiolucency located in the radicular area of the left second premolar. Previous radiographic examina- tions and a cone beam CT study were requested for lesion study. An incisional biopsy was performed for histopathologic analysis. Macroscopic examination showed a sample with a white and gelatinous appearance. Microscopically, the lesion was com- posed of haphazardly arranged stellate, spindle-shaped, and round cells in an abundant, loose myxoid stroma. Histopatholo- gicfindings were compatible with odontogenic myxoma. Immu- nohistochemical study was performed to rule out other pathologic entities. The complete elimination of the lesion was performed by block resection followed by reconstruction and subsequent clinical controls. The case is reported under the informed consent of the patient. NASOPALATINE DUCT CYST IN AN ELDERLY EDENTULOUS PATIENT. LETICIA BEATRIZ DA CRUZ SANTOS, BEATRIZ BEZERRA RIBEIRO, GIOVANNA DE ALCANTARA SANTOS, LIONEY NOBRE CABRAL and, TIAGO NOVAES PINHEIRO Nasopalatine duct cyst in edentulous areas may be associ- ated with local pain, presence of mucosal patency of the duct, and even secondary infection. The present study aims to report the case of a 52-year-old black female patient who attended the dental institution complaining of pain in the anterior palate area. The patient reported a history of previous procedure to puncture and remove fluid from the anterior maxilla, in the past 6 years, as an urgency procedure but evaded treatment due to partial remission of the symptoms at that time. In the intrao- ral clinical examination, there was no presence of color alter- ation as well as swelling in the anterior palate area. The tomographic examination suggested a nasopalatine duct cyst. An excisional biopsy was performed and the material was referred for histopathologic analysis, confirming the diagnosis. After 6 months of follow-up, the patient was released with no further complications. MULTIPLE APPROACH OF A LARGE CYSTIC LESION IN THE ANTERIOR MAXILLA: PEARLS AND PITFALLS. LETICIA BEATRIZ DA CRUZ SANTOS, BETH ^ ANIA CAMARGO PINHEIRO, DANIEL FROTA DE SOUZA, PAMELA OLIVEIRA SANTOS, PAULA GOMES SOARES and, TIAGO NOVAES PINHEIRO We report the challenges faced in the treatment of a large cystic lesion in the anterior maxilla. A 32-year-old woman pre- sented herself to the urgency service, complaining about discom- fort in the region of nonvital tooth #22. Endodontic treatment was started and the patient reported to the oral medicine disci- pline of the authors’ institution. Imaging and clinical examina- tion revealed a large cystic lesion involving the hard palate, nasal cavity, and the anterior portion of the maxillary sinus. A cystic decompression was performed along with an incisional biopsy that led to a histopathologic diagnosis of periapical cyst. A second surgical approach tried to enucleate the lesion but the ostium of decompression remained open, thereby impairing bone formation. A third approach was performed along with alloge- neic particulate bone graft and reabsorbable membrane barrier positioning. Radiographic follow-up showed the graft integration and good recovery of the lesion after 4 months of follow-up care. PAPILLARY SQUAMOUS CELL CARCI- NOMA: A CASE REPORT. TARSILA DE CARVALHO FREITAS RAMOS, L  ISIA DALTRO OOOO ABSTRACTS Volume 129, Number 1 e47