PMC8439264_01
The CT scan shows a 3.5 cm2 x 4.0 cm2 expansive neoplasm located in the right TMJ region (a, horizontal plane, white rectangular region), with an expansile osteolytic process that was eroding the mandibular condyle (b, coronal plan, white arrows). MRI results confirmed an irregular neoplasm surrounding the mandibular condyle with an unclear joint space (c, coronal plan, white rectangular region).
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A computed tomography (CT) scan showed a 3.5 cm2 x 4.0 cm2 expansive neoplasm located in the right TMJ region (Figure 1a, horizontal plane, white rectangular region), with an expansile osteolytic process that was eroding the mandibular condyle (Figure 1b, coronal plan, white arrows) and extending into the middle cranial fossa. MRI results confirmed an irregular neoplasm surrounding the mandibular condyle with an unclear joint space (Figure 1c, coronal plan, white rectangular region).
The mandibular condyle and disc were surrounded and being eroded by the neoplasm (a, white dashed region). A reverse L-shaped osteotomy line was drawn at the posterior part of the ramus. The proximal bone segment was then moved superiorly to reconstruct the mandibular condyle and fixed using an L-shaped miniplate (b, white dashed region shows temporal muscle). (c) A 3D reconstruction of postoperative CT images show the reconstructed mandibular condyle. (d) Depicts the neoplasm (black arrow) and damaged mandibular condyle (white arrow).
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Additionally, the mandibular condyle and disc were surrounded and being eroded by the neoplasm (Figure 2a, white dashed region). The proximal bone segment was then moved superiorly to reconstruct the mandibular condyle and fixed using an L-shaped miniplate, while the temporalis myofascial flap was reversed anteroinferiorly to fill into the space. (Figure 2b, white dashed region shows temporal muscle). A 3D reconstruction of postoperative CT images show the reconstructed mandibular condyle (Figure 2c). Figure 2d depicts the neoplasm (black arrow) and damaged mandibular condyle (white arrow).
Histologically, the lesion consisted of both polygonal and round mononuclear chondroblasts with grooved nuclei as well as multinucleated giant cells (a, black arrows) in an eosinophilic cartilaginous matrix. An immunohistochemical stain for S-100 protein was positive in the tumor cells (b).
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Histologically, the lesion consisted of both polygonal and round mononuclear chondroblasts with grooved nuclei as well as multinucleated giant cells (Figure 3a, black arrows) in an eosinophilic cartilaginous matrix. An immunohistochemical stain for S-100 protein was positive in the tumor cells (Figure 3b), suggesting their chondroid differentiation.