[Rare parotid gland tumors: enhanced computed tomography and pathological correlation]

Abstract

Objective: To investigate the correlation between enhanced computed tomography (CT) findings and pathological results of rare parotid gland tumors, and improve diagnosis accuracy.

Methods: The enhanced CT manifestations of 22 cases with pathologically documented rare parotid gland tumors, which included 6 cases of basal cell tumor, 5 cases of myoepithelioma, 4 cases of vascular invasion, 3 cases of lymphatic cyst, 3 cases of lipoma, and 1 case of chondrosarcoma, were retrospectively analyzed. The location, size, shape, density, and relationship with surrounding structure were evaluated on CT images.

Results: The enhanced CT showed that basal cell tumors occurred in the superficial lobe of the parotid gland, with clear boundary, within the cystic lesion. The lesions were moderate to obviously enhanced, which may be accompanied by enlarged lymph nodes. Myoepithelial tumors were located in the superficial lobe of the parotid gland, with a small cystic prone and microcalcification within a few cases. The lesions were moderate to obviously enhanced. Hemangiomas of soft tissue mass prominent in the parotid gland surface were mild to significantly enhanced. Larger lesions may occupy the entire parotid gland, with uneven density and visible vein stone. The CT density values of the lymphatic cyst were usually higher. Chondrosarcoma mainly manifested cystic mass at the calcification edge. Lipoma with fat density mass exhibited clear boundary without enhancement. Fiber separation could be observed in the lesion.

Conclusion: CT can reflect the pathological features of rare parotid gland tumors by demonstrating their corresponding imaging features. Enhanced CT is the most effective means of imaging to identify the nature of rare tumor of the parotid gland lesions.

图 1. 左侧腮腺肿块伴多发囊变区（↑），实性部分明显强化，伴双侧颈动脉鞘旁淋巴结增大（▲）

Fig 1 The left parotid mass with multiple cystic areas(↑), the solid part of the tumor significantly enhanced, and enlarged lymph nodes around the bilateral carotid sheath(▲)

图 2. 肿瘤位于左侧腮腺浅叶后下极，病变推挤周围血管（↑）

Fig 2 Tumor occurred in the superficial lobe after the lower pole of the left parotid gland, pushing peripheral vascular disease (↑)

图 3. 肿瘤位于左侧腮腺浅叶下极，病变下边缘见结节状突起，明显强化（↑）

Fig 3 Tumor occurred in the superficial lobe of the left parotid gland, and lower edge of the lesion with marked enhancement nodular projections (↑)

图 4. 右侧腮腺深、浅叶肿块，病变内见多发结节状强化（↑）

Fig 4 Multiple enhanced nodules located the right side deep and superficial lobe of the parotid gland tumor(↑)

图 5. 左侧腮腺深叶肿块，病变边界不清，内部有散在小静脉石（↑）

Fig 5 The deep lobe of the left parotid gland tumor with unclear boundary and internal scattered small phleboliths (↑)

图 6. 右侧腮腺后下份为类圆形囊性低密度灶，病变边界清晰，病变未见强化

Fig 6 The round hypodense cystic lesion with clear boundary and no enhancement occurred in after the lower part of the right parotid gland

图 7. 右侧腮腺后下极脂肪密度肿块影，病变边界清晰，内见纤维分隔（↑），病变无强化

Fig 7 The fat density mass with clear boundary and the fibrous septa (↑) occurred in after the lower part of the right parotid gland, and the lesion without enhancement

图 8. 左侧腮腺深叶囊性为主，含边缘钙化、骨化成分的肿块（↑），呈哑铃状，边界清晰，病灶无强化

Fig 8 The deep lobe of the left parotid gland tumor was mainly of the cystic lesions, containing the edge of calcification, ossification mass component (↑), and showed a dumbbell-shaped, clear boundary and no enhancement