Removal of unexpected schwannoma with superficial parotidectomy using modified-Blair incision and superficial musculoaponeurotic system folding: A case report

BACKGROUND When a firm facial mass in the cheek region is associated with a high index of clinical suspicion of its being of parotid gland origin,preventive parotidectomy is invariably performed.We report a rare case of a schwannoma that was suspected to be of parotid gland origin in a patient,who underwent successful surgical management using a modified-Blair incision and superficial musculoaponeurotic system(SMAS)layer folding method.CASE SUMMARY A 27-year-old woman presented to the hospital for evaluation of a firm,fixed,non-tender mass(2.5 cm×3.5 cm),located anterior to the right ear,of 1 year’s duration.Contrast-enhanced facial computed tomography revealed a wellencapsulated,low-density mass adherent to the superficial lobe of the right parotid gland,with a high index of clinical suspicion of an accessory parotid gland mass.The patient was scheduled to undergo resection of the mass and superficial parotidectomy.She underwent surgery using a modified-Blair incision,and the SMAS layer was folded posteriorly to reconstruct the defect.Histopathological examination confirmed the diagnosis of a schwannoma.,and we observed no postoperative complications such as hematoma,infection,or abnormal facial expressions.The incision scar was unnoticeable 2 mo postoperatively,and the facial contour was maintained without any differences between the affected and unaffected sides.CONCLUSION We used a modified-Blair incision and SMAS layer folding method to achieve aesthetically good results following resection of a rare schwannoma with superficial parotidectomy in the cheek region.

MR imaging of cheek lesions of Kimura’s disease: Focusing on the signal abnormalities and the relationship with superficial musculoaponeurotic systems

Background and Purpose: Kimura’s Disease (KD) is a rare benign chronic eosinophlic inflammatory disorder, characterized by angiolymphoid proliferation with peripheral eosinophilia and elevated serum immunoglobulin E. Most lesions occur in the head and neck regions. To the best of our knowledge, the relationship between subcutaneous cheek lesion of KD and the surrounding structures including superficial musculoaponeurotic systems (SMAS) has never been reported. The purpose of this study was to describe MR imaging findings of cheek subcutaneous lesion of KD and adjacent SMAS. Materials and Methods: Seven cheek subcutaneous lesions of 5 patients histopathologically proved KD were evaluated. We retrospectively evaluated the MR imaging findings of subcutaneous lesions for signal intensity in each imaging sequence, the border of the lesions, and appearance of SMAS. Results: All cheek lesions were displacing normal fat tissue. These lesions showed ill-defined border (7/7), slightly high signal intensity on T1-weighted images (7/7), and intermediate (1/7) or high signal intensity (6/7) on T2-weighted images. Cheek lesions were enhanced by intravenous injection of gadolinium to signal intensity close to that of fat tissue (3/4), and in one case, the avid enhancement of the mass was seen (1/4). All lesions attached to the outer surface of SMAS, however, only one out of 7 lesions distributed below the SMAS without tearing of the layers. SMAS below the lesion showed high signal intensity on T2-weighted images in two lesions (2/7). Conclusion: KD should be included in the differential diagnosis when a cheek mass presents with non-specific signal intensities and irregular border, which attaches to but does not interrupt SMAS on MR imaging.