Diagnostic yield of ThinPrep preparation in the assessment of fine-needle aspiration biopsy of salivary gland neoplasms.

BACKGROUND

Fine-needle aspiration (FNA) has been widely recognized as an important modality in assessment of salivary gland neoplasms, and specimens are often processed as conventional smears. We conducted the current study to evaluate the diagnostic utility of ThinPrep preparation as an alternative method for assessment of salivary gland neoplasms.

METHODS

A computer SNOMED search from the pathology database at our institution between July 1999 and June 2012 was conducted to identify FNA cytology specimens of salivary gland lesions for which follow-up surgical specimens revealed neoplasms. The FNA specimens were divided into two cohorts: one cohort consisted solely of the specimens in which all needle passes were collected into CytoLyt solution and only ThinPrep slides were prepared; and the other cohort included the specimens prepared with conventional smears. Diagnostic performance of the two cohorts was compared.

RESULTS

Nondiagnostic rate of ThinPrep preparation was significantly higher than that of conventional smears (40% vs.18%; P <0.001). Among the diagnostic specimens, although more indeterminate diagnoses were generated in ThinPrep preparation compared to conventional smears (40% vs. 26%; P = 0.024), absolute cytohistologic concordant rate for the positive cases (type of neoplasms specified) is similar between the two preparations (80% vs. 86%; P = 0.354). Furthermore, there is no significant difference in rate of accurate diagnosis (correct typing of benign versus malignant neoplasm) between the two preparations (70% vs. 81%; P = 0.057).

CONCLUSIONS

ThinPrep may be considered as another practical method of specimen preparation in the assessment of salivary gland neoplasms, particularly when FNA is performed without immediate assistance from cytology.