Pitfalls in Salivary Gland Fine-Needle Aspiration Cytology: Lessons From the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytology

Abstract

Context.—We use data from the College of American Pathologists Interlaboratory Comparison Program in Nongynecologic Cytology to identify common diagnostic errors in salivary gland fine-needle aspiration (FNA). Objective.—To identify salivary gland FNA cases with poor performance characteristics in the Nongynecologic Cytology Program surveys, so that the most common diagnostic pitfalls can be avoided. Design.—A retrospective review of the College of American Pathologists Nongynecologic Cytology Program's cumulative data from 1999 to 2003 revealed the most common false-positive and false-negative interpretations on FNA for common salivary gland lesions. Slides that performed poorly were then reviewed to identify the cytologic characteristics that may have contributed to their poor performance. Results.—A total of 6249 participant responses with general interpretations of benign (n = 4642) or malignant (n= 1607) were reviewed. The sensitivity and specificity of the participant responses for correctly interpreting the cases as benign or malignant were 73% and 91%, respectively. Benign cases with the highest false-positive rates were monomorphic adenoma (53% false-positive), intraparotid lymph node (36%), oncocytoma (18%), and granulomatous sialadenitis (10%). Malignant cases with the highest false-negative rates were lymphoma (57%), acinic cell carcinoma (49%), low-grade mucoepidermoid carcinoma (43%), and adenoid cystic carcinoma (33%). Selected review of the most discordant individual cases revealed possible explanations for some of the interpretative errors. Conclusions.—These data confirm the difficulty associated with interpretation of salivary gland FNA specimens. Cytologists should be aware of the potential false-positive and false-negative interpretations that can occur in FNAs from this organ site in order to minimize the possibility of diagnostic errors.

Accuracy of Fine Needle Aspiration Biopsy in Diagnosing Parotid Gland Malignancy

“…10 Most of the studies reviewed attribute false negative rates to sampling errors. [10][11][12] According to a 2005 review, 13 the malignant neoplasm cases of salivary gland with the highest false negative rates were mucoepidermoid carcinoma, acinic cell carcinoma, and adenoid cystic carcinoma. These were the seven malignancies that were falsely diagnosed to be benign by FNAB in this study, with four (4) cases of mucoepidermoid carcinoma and one (1) case of acinic cell carcinoma diagnosed as pleomorphic adenoma and two (2) cases of adenoid cystic carcinoma diagnosed as trichoblastoma and pleomorphic adenoma respectively.…”

The Contributory Role of Cell Blocks in Salivary Gland Neoplasms Fine Needle Aspirations Classified by the Milan System for Reporting Salivary Gland Cytology

“…In all three cases, the CBs were non-contributory and contained less than 10 cells. In a series of 6249 reviewed cases performed by the College of American Pathologists, the lymphoma cases featured the highest false-negative rate at 57% [33]. In recent MSRSGC analyses, 10 lymphoma cases were misinterpreted in a non-neoplastic category and 9 lymphoma cases in an AUS category [4,23,25,26,34].…”

Cytopathology of Intraoral Salivary Gland Tumours and Tumour-Like Lesions: Diagnostic Challenges and Pitfalls

“…Majority of intraoral minor SG tumours are malignant in contrast to major SG tumours where benign tumours outnumber the malignant ones [4]. While some studies documents mucoepidermoid carcinoma (MEC) as the most common malignant tumour of minor SGs, other studies documents adenoid cystic carcinoma (ADCC) or pleomorphic adenoma (PA) as the most common tumour [5][6][7][8][9][10]. This difference in frequency of these histological types may be attributed to the differences in geographic location, race and varied clinical presentation.…”

“…The hard palate is the most common site of occurrence [3][4][5]. Cytopathological evaluation of intraoral SG tumours is challenging as these tumours show heterogeneity and considerable morphological diversity and overlap [6]. The correct preoperative cytopathological diagnosis of intraoral SG tumours is essential for deciding further course of management and treatment.…”