Juxtacortical osteosarcoma of mandible
A 43-year-old female patient had come with the complaint of pain and swelling in the left angle of mandible which was progressively increasing in size since the last 4 months. Pain was continuous and was aggravated while having food and while opening the mouth. Patient had been operated 15 years back for swelling at the same site, records for which were not available.\nOn inspection, a swelling was seen in the left angle of the mandible measuring around 7 cm × 5 cm in diameter. The skin over the swelling was puckered with a healed scar which was probably due to the previous surgery [].\nOn palpation, there was a firm to hard tender swelling in the left angle of mandible extending from left first molar to the third molar region which was fixed to underlying bone. The involved teeth showed no signs of mobility or resorption. There was no paresthesia in the area supplied by inferior alveolar nerve. The mucosa over the swelling was normal and showed no secondary changes.\nOPG showed scattered calcification superimposed over the left third molar and ramus region on the left side []. CT scan showed a well-encapsulated juxtacortical mass in left angle of mandible with areas of calcification [Figures and ]. There was erosion of cortical bone in the third molar and the anterior ramus region with some intramedullary extension. A well-defined swelling overlying the left mandibular body with calcified/ ossified areas was seen in the soft tissue.\nIncisional biopsy was done intraorally and the extrabony component of the mass was removed. The extraosseous mass was well encapsulated but fixed to the underlying bone which was eroded in the third molar region where the mass was found infiltrating into bone and was not separable. The section of specimen showed multiple irregular calcified masses some of them measuring almost 2 cm × 3 cm in diameter.\nH and E-stained section showed highly cellular areas of connective tissue in which lace-like pattern of neoplastic osteoid tissue was seen. There was no demarcation between tumor osteoid and rest of connective tissue cells. Osteoid tissue was surrounded by abnormally plump osteoblast and immature bone. Few osteoblasts exhibited abnormal mitosis. Rest of the connective tissue showed plump, pleormorphic, and haphazardly arranged cells with vesicular nuclei []. Moderate vascularity and areas of hemorrhage were also seen. Overall picture was suggestive of a low-grade osteosarcoma involving the mandible.\nThe patient was subjected to a whole body examination and relevant radiographs were done to rule out primaries elsewhere. The radiographs were normal and it was confirmed as primary osteosarcoma of the mandible.\nWithin 2 weeks of the biopsy, the patient developed trismus and increasing pain in the same region. The skin over the lesion was fixed and nonpinchable. Repeat CT scan showed involvement of masseter muscle along with the skin.\nPatient underwent a hemimandibulectomy with wide excision of the tumor mass with involved skin. Involved skin paddle was marked with a circular incision which was connected anteriorly to the left commisure of the lip. It was then extended along the paramedian line all along the neck to the clavicle where it was extended horizontally. Blunt dissection was done through layers. Lower border of mandible was exposed. The tumor mass along with the overlying skin and involved soft tissue and hemimandible on that side from canine to condyle was excised []. Adequate clearance was achieved on all aspects and was confirmed with fresh frozen section. A pectoralis major myocutaneous flap was raised and used to line the intraoral defect, while the overlying skin defect was covered with cervical rotation flap []. Postoperative period was uneventful and patient after regular follow-up for 1 year was symptom free with no signs of local recurrence or distant metastasis [].