Mandibular Solitary Intraosseous Myofibroma: A Case Report and Review of Literature

Abstract

Abstract Introduction/Objective Myofibroma (MF) is a benign soft tissue neoplasm of myofibroblastic origin, which frequently occurs in children and rarely presents as an intraosseous neoplasm. Other benign mesenchymal lesions and other low-grade malignant soft tissue neoplasms mimic morphologically to MF, thus making the diagnosis of MF challenging and crucial. Methods/Case Report Herein, we describe a 9-year-old female who was referred to an oral surgeon by her dentist, for evaluation of a radiolucent lesion on her left mandible associated with impacted tooth #21 and 22, which had slightly increased in size over 2 weeks. Her medical history was non-contributory other than asthma. Clinical examination revealed a large 5x4 cm firm mass slightly tender and causing expansion along the buccal as well as lingual aspects of the mandible in the canine and first premolar region. A radiograph CBCT of the mandible revealed malposed tooth #21 and 22 and unilocular radiolucency associated with the crowns #21 and 22. No evidence of calcifications within the lucency was noted. The patient underwent an incisional biopsy of the mandibular lesion, which showed a benign tumor composed of bland spindled cells arranged in fascicles with scattered thin walled blood vessels. Mitotic figures were inconspicuous and there was no discernible necrosis. Immunohistochemical stains show that the lesional cells are positive for SMA and Vimentin (Fig. 1 A-D, H&E, SMA, Ki-67, Vimentin) and negative for S100, desmin and CD34. Ki-67 (proliferative index) is interpreted to be low (<5%). Results (if a Case Study enter NA) NA Conclusion Mandibular intraosseous MF is extremely rare. Clinico-pathologic correlation, immunohistochemical features and sometimes molecular studies are essential for correct diagnosis and to rule out other benign and low-grade soft tissue neoplasms that mimic MF morphologically and radiographically. Thus MF, though rare neoplasm should be considered in the differential diagnosis of unilocular or multilocular radiolucent lesions of the jaws.