Analysis of ultrasonography and cytology potential in differential diagnosis of major salivary gland neoplasms

Background: Salivary gland tumors account for up to 5% of all head and neck neoplasms. Ultrasonography is one of the main diagnostic modalities for the salivary gland pathology; however, its diagnostic potential is under scrutiny. Fine needle aspiration cytology is considered the main diagnostic method, although its role in the differential diagnosis is disputable.

Objective: To identify, based on morphology results, the effectiveness of the main ultrasonographic signs indicating major salivary gland neoplasms in the differential diagnosis and study these signs, to evaluate the effectiveness of fine needle aspiration in the diagnosis of benign and malignant major salivary gland neoplasms.

Materials and methods: This retrospective study evaluated a group of 220 patients. We calculated sensitivity, specificity, and accuracy of qualitative ultrasonographic signs of salivary gland neoplasms, analyzed the fine needle aspiration effectiveness, and compared results accuracy by calculating Pearson’s empirical χ-square.

Results: Common ultrasonographic signs of benign salivary gland neoplasms included a clear contour (97.5%) and decreased echogenicity (72.7%). Malignant tumors frequently presented with a clear contour (76.7%), uneven contour (72.1%), and decreased echogenicity (69.8%). Fine needle aspiration sensitivity and specificity in the diagnosis of benign neoplasms were 75.5% and 53.6%, respectively. Fine needle aspiration sensitivity and specificity in respect of malignant tumors were 50% and 94%, respectively. Pearson’s χ-square value for the clear contour had significant differences in favor of benign neoplasms.

Discussion: Benign and malignant salivary gland neoplasms often have a similar ultrasonographic pattern. A significant diagnostic sign of malignant tumors is the uneven contour. We compared the effectiveness of cytological differentiation between benign and malignant neoplasms and found high rates of specificity and accuracy for malignant tumor diagnosis.

Conclusions: Clear contour and decreased echogenicity are significant ultrasonographic signs in the differentiation of benign neoplasms. Uneven contour is a significant differentiating factor for malignant neoplasms. Cytology can be used for initial morphology in diagnosing major salivary gland neoplasms, but in half of the cases it fails to identify the nature and type of the tumor.

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