Parotid gland ancient schwannoma is an extremely rare entity, with only 6 cases reported to date. Ancient schwannoma present degenerative alteration, including cystic changes, hyalinizing stroma, hemorrhages, infiltration of macrophages, and cellular atypia with hyperchromatic nuclei. These factors have the potential to mimic malignant tumors, resulting in an overestimation of diagnosis and subsequent inappropriate management. In the present case, we report a case of parotid gland ancient schwannoma, which developed relatively fast degenerative alteration without a large-sized mass. We reviewed all the cases of parotid ancient schwannoma, and suggest that the character of parotid gland tissue can deceive the change of tumor growth size. We also suspect that pre-surgical manipulation, such as FNAB or CNB, can cause degenerative changes in a relative short period. It is important to consider reactive degenerative alteration of schwannoma, and not to misinterpret as a malignant entities, notably when needle biopsy history is present.

Ⅰ. INTRODUCTION
Ⅱ. CASE REPORT
    Clinical History
    Histopathological Features
Ⅲ. DISCUSSION
    Duration Period
    Ischemic Necrosis
    Traumatic Injury
REFERENCES

• 김도연(부산대학교 치의학전문대학원 구강병리학교실) | Do Yeon Kim (Department of Oral Pathology, School of Dentistry, Pusan Nation University)
• 박혜련(부산대학교 치의학전문대학원 구강병리학교실) | Hae Ryoun Park (Department of Oral Pathology, School of Dentistry, Pusan Nation University)
• 송재민(부산대학교 치의학전문대학원 구강악안면외과학교실) | Jae-Min Song (Department of Oral and Maxillofacial Surgery, School of Dentistry, Pusan Nation University) Corresponding author