Fine needle aspiration biopsy: in the diagnosis of salivary gland neoplasms compared with histopathology

Malignant salivary gland tumors: agreement between fine needle aspiration biopsy, incisional biopsy and final histopathological diagnostic

BACKGROUND

Incisional biopsy is indicated for intraoral tumors, but it is a contraindicated surgical procedure for major salivary glands. To avoid complications and facilitate diagnosis, fine needle aspiration biopsy (FNAB) is a type of biopsy widely used for preoperative diagnosis in these glands.

MATERIAL AND METHODS

The aim of this study was to analyze the agreement between the diagnosis by FNAB (major glands), incisional biopsy (minor glands) and histopathological analysis of the surgical specimen in salivary gland tumors from a database (medical records) of patients treated in a cancer treatment reference center in the Northeast region of Brazil.

RESULTS

The sample consisted of 110 cases, being 86 of them malignant tumors in major salivary glands (parotid gland=73; submandibular gland=13) and 24 cases in minor salivary glands (palate). The female gender was the most affected (57.3%), especially in patients over 60 years (42.7%). In the TNM classification, 41.8% of the cases were in T2 at the time of diagnosis, with most of the regional lymph nodes in N0 (85.5%) and 87.3% of the cases in M0. FNAB was able to identify malignant neoplasms in 68.6% of the cases (n=59), while incisional biopsy in palatal tumors obtained agreement of 75% of the cases (n=18). The analysis revealed that tumors classified as T3-T4 (p=0.012) showed greater agreement between pre- and post-surgical diagnosis.

CONCLUSIONS

The results obtained in this study indicate that FNAB has similar accuracy to incisional biopsy in providing satisfactory preoperative diagnoses of malignant tumors in salivary glands.

Correlation Between Fine Needle Aspiration Cytology (FNAC) and Permanent Histopathology Results in Salivary Gland Masses

Objective

Fine-needle aspiration cytology (FNAC) has been widely accepted as a diagnostic safe method for preoperative assessment of salivary gland lesions. This diagnostic tool is inexpensive, easy to perform, relatively painless and it provides useful information to differentiate between benign and malignant salivary gland tumors that helps in the management and surgical planning. This study was undertaken to compare FNAC results with permanent histopathological findings of salivary gland tumors in order to assess its diagnostic accuracy.

Materials and methods

A total of 37 archived salivary gland FNAC specimens collected between January 2001 and January 2018 were correlated with proven histopathology findings. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were calculated. False negative and false positive cases were determined.

Results

There were 20 female and 17 male patients. Parotid tumors count for 62.2% and submandibular tumors 37.8%. All cases of malignancy on FNAC were proven to be malignant on the final pathology findings. All cases that were suspicious for malignancy on FNAC were proven to be malignant as well. In addition, three false negative cases were seen and no false positive cases among all FNAC cases. In our series, the overall sensitivity and specificity were 90.3% and 100%, respectively. The positive and negative predictive values were 100% and 57.1%, respectively. The diagnostic accuracy was 91.4%.

Conclusion

This study demonstrated that FNA cytology of the salivary gland is a useful technique for diagnosis of salivary gland lesions. Insufficient cellularity was the most important factor that resulted in incorrect cytological interpretation.

Use of fluorescent in-situ hybridisation in salivary gland cytology: A powerful diagnostic tool

OBJECTIVE

Salivary gland cytology is challenging because it includes a diversity of lesions and a wide spectra of tumours. Recently, it has been reported that many types of salivary gland tumours have specific molecular diagnostic signatures that could be identified by fluorescent in-situ hybridisation (FISH). The aim of the present study was to demonstrate the feasibility and efficiency of FISH on routine cytological salivary gland smears.

METHODS

FISH was conducted on 37 cytological salivary gland smears from 34 patients. According to the cytological diagnosis suspected, MECT1/MAML2 gene fusion and rearrangements of PLAG1, MYB, or ETV6 were analysed. The presence and percentages of cells that had gene rearrangements were evaluated. Results were compared with the histological surgical samples, available from 26 patients.

RESULTS

The PLAG1 rearrangement was observed in 12/20 (60%) cases of pleomorphic adenoma. MECT1/MAML2 gene fusion was observed in 1:2 mucoepidermoid carcinomas but was not observed in five other tumours (two pleomorphic adenomas, one Warthin's tumour, one mammary analogue secretory carcinoma [MASC] and one cystic tumour). MYB rearrangement was observed in 4/4 adenoid cystic carcinomas. ETV6-gene splitting identified one MASC.

CONCLUSION

Overall, FISH had a specificity of 100% and a sensitivity of 66.7%. When FISH and cytological analyses were combined, the overall sensitivity was increased to 93.3%. It can thus be concluded that when the FISH analysis is positive, the extent of surgery could be determined with confidence pre-operatively without needing a diagnosis from a frozen section.

Factors Influencing the Outcome of Ultrasound-Guided Fine-Needle Aspiration for Salivary Gland Lesion Diagnosis

OBJECTIVES

This study aimed to assess multiple factors influencing the outcomes of ultrasound (US)-guided fine-needle aspiration (FNA) of salivary gland lesions.

METHODS

From 2008 to 2013, a single radiologist performed US-guided FNA of salivary gland lesions in 243 patients. With the exclusion of pure cysts, poor image quality, and insufficient static image cases, 218 salivary gland lesions in 218 patients were included. The composition, size, location, and vascularity of the lesions were retrospectively investigated on the basis of sonographic findings by the same radiologist. The relationship between sampling adequacy and multiple factors was compared, and the diagnostic accuracy of US-guided FNA of salivary gland lesions was calculated by using the final diagnosis as a reference standard.

RESULTS

The sampling adequacy rate for US-guided FNA of the 218 salivary gland lesions was 96.8% (211 of 218). A significant difference was observed in the composition and vascularity of the lesions (P < .0001), whereas there was no significant difference in the patient age and sex, lesion size, lesion location, and needle size. The rate of inadequate sampling increased in predominantly cystic lesions compared with solid lesions as well as in low-vascularity lesions compared with high-vascularity lesions. Of the 218 lesions, 178 (81.7%) were ultimately diagnosed, and most were benign (162 of 178 [91.0%]). When 3 cases with indeterminate cytologic results were excluded, the sensitivity, specificity, positive and negative predictive values, and accuracy of US-guided FNA of salivary gland lesions were 64.3%, 98.8%, 81.8%, 97.0%, and 96.0%, respectively.

CONCLUSIONS

When using US-guided FNA to diagnose salivary gland lesions, sampling adequacy depends on the composition or vascularity of the lesions.