PMC4377457_01
((a) and (b)) Extraoral evaluation revealed a gross swelling over the left mandible.
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Extraoral evaluation revealed a gross swelling over the left mandible (Figure 1).
(a) Biphasic tumor composed of islands of benign odontogenic epithelium and an abundant malignant mesenchymal component. H&E stain, x50. (b) The malignant mesenchymal component consists of plump and spindle stromal cells which show mild to moderate cytologic atypia and numerous mitotic figures arranged in storiform and herringbone fashion. H&E stain, x100.
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Histopathological examination revealed a biphasic tumor composed of inconspicuous islands of benign odontogenic epithelium and an abundant malignant mesenchymal component with marked cellularity, nuclear pleomorphism, hyperchromatism, and moderate mitotic figures (Figure 2).
(a) Reactivity to Cytokeratin AE1/AE3 in the epithelial component, lack of reactivity in the mesenchymal component. Immunohistochemical stain with anti-Cytokeratin AE1/AE3 antibody, x50. (b) Reactivity to Vimentin in the mesenchymal component. Immunohistochemical stain with anti-Vimentin antibody, x400. (c) Reactivity to Ki67 in the mesenchymal component with a labeling index of 30%. Immunohistochemical stain with anti-Ki67 antibody, x50.
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Ki67 (Figure 3). CK was strongly positive in the odontogenic epithelium and negative in the mesenchymal component, while Vimentin was strongly positive in the mesenchymal component and negative in the odontogenic epithelium. Ki67 was expressed by 30% of the mesenchymal cells.
Panoramic radiograph (a) and axial CT scan (b) revealing an ill-defined radiolucent lesion around an impacted mandibular left first molar.
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Four months later a panoramic radiograph and CT scan of head and neck were performed disregarding locoregional and distant metastases while also revealing again the same ill-defined radiolucent lesion around an impacted mandibular left first molar (Figure 4).
Gross photograph of the cut surface of the left half of the mandible showing a solid gray tumor mass.
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The excised specimen consisted of the left half of the body and ramus of the mandible measuring 5 x 4.2 x 3 cm with a gray solid tumor mass of 1.8 cm with widely clear margins (Figure 5).
(a) Reactivity to PCNA in both components. Immunohistochemical stain with anti-PCNA antibody, x50. (b) Reactivity to p53 only in the mesenchymal component. Immunohistochemical stain with anti-p53 antibody, x400.
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PCNA and p53 (Figure 6). PCNA was strongly positive in both components, while p53 was strongly positive only in the mesenchymal component.
Panoramic radiograph showing area of mandibular resection with no evidence of recurrence 1 year after surgery.
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Currently, one year after the surgical procedure, the patient is clinically and radiologically disease-free (Figure 7).