case_images: PMC7481918_01
case_images: Preoperative clinical photograph of the right preauricular swelling. (a) Right lateral facial view shows the swelling extending superoinferiorly from a point anterior to the helix of the external ear until the lower border of the mandible; anteroposteriorly, the swelling is seen extending from the angle of the mouth to the posterior border of the mandible; the ear lobe is deflected outward and elevated, and the skin overlying the swelling appears free of any ulceration, puckering, or discharge. (b) Frontal facial view shows the swelling causing facial asymmetry and obliterating the view of most of the right external ear; there is no clinical evidence of facial nerve weakness or deficit.
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case_images: fig1
case_images: There was no lymph node involvement or facial nerve deficit (Figure 1).
case_images: Preoperative radiographic examination of the right preauricular swelling. (a) Contrast-enhanced computed tomography axial section at the level of mandibular teeth shows a well-defined mass lesion in the superficial lobe of the right parotid gland, without any underlying bony erosion and normal-appearing pharynx, larynx, and parapharyngeal spaces. (b) Magnetic resonance imaging coronal section along the posterior border of the mandible shows a large, heterogeneous, well-demarcated solid mass lesion within the right parotid superficial lobe and measuring 10 x 7 x 8 cm at maximum dimensions.
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case_images: fig2
case_images: While confirming the CT findings, head and neck MRI further demonstrated a well-demarcated, heterogeneous, mass lesion measuring 10 x 7 x 8 cm in maximum dimension (Figure 2).
case_images: Intraoperative photograph showing (a) the surgical plane for extracapsular dissection of the right parotid tumor and (b) the excised tumor specimen.
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case_images: fig3
case_images: The intraoperative period was unremarkable, and the patient did not require any blood transfusions (Figure 3).
case_images: Histological examination of the excised tumor specimen showing (a) a partially encapsulated mass lesion containing myoepithelial and ductal proliferation, with stromal hyalinization, squamous metaplasia, and keratinization; epithelial islands exhibiting papillary configuration, large cysts surrounded by inflammation, focal areas of chondromyxoid changes and fibrosis, and tumor islands approaching and penetrating the capsule are evident (HE original magnification x4); (b) extensive squamous metaplasia and keratin cyst formation are conspicuous at higher magnification (HE original magnification x10).
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case_images: fig4
case_images: While the tumor sections showed no evidence of malignant change, there was extensive squamous metaplasia and keratin cyst formation, which were atypical for PA (Figure 4).
case_images: Postoperative clinical photograph taken 6 weeks postsurgery. (a) Lateral facial view shows healing surgical incision without any obvious postoperative sequelae. (b) Symmetric facial appearance observed in the frontal facial view, with no clinical weakness of muscles of facial expression.
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case_images: fig5
case_images: At 6 weeks postsurgery, the patient had unremarkable wound healing without any neurological deficit of the facial nerve (Figure 5).
case_images: Postoperative clinical photograph taken 7 years postsurgery with facial gestures eliciting unrestrained action of different muscles of facial expression. (a) Unremarkable healing of the surgical wound without any scarring and the patient is seen smiling. (b) Frontal facial view showing symmetric appearance and the patient is seen puffing the cheeks. (c, d) Bilateral symmetric eyelid closure and opening. (e) The patient is seen grinning broadly.
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case_images: fig6
case_images: As of December 2019, the patient had a recurrence-free follow-up period of 7 years and presented with normal activity of muscles of facial expression, indicating the absence of any long-term facial nerve weakness (Figure 6).