Re: Role of fine needle aspiration cytology in the preoperative investigation of branchial cysts

Cytologic separation of branchial cleft cyst from metastatic cystic squamous cell carcinoma: A multivariate analysis of nineteen cytomorphologic features

BACKGROUND

The separation of branchial cleft cysts from metastatic cystic squamous cell carcinomas in adults can be clinically and cytologically challenging. Diagnostic accuracy for separation is reported to be as low as 75% prompting some authors to recommend frozen section evaluation of suspected branchial cleft cysts before resection. We evaluated 19 cytologic features to determine which were useful in this distinction.

METHODS

Thirty-three cases (21 squamous carcinoma and 12 branchial cysts) of histologically confirmed cystic lesions of the lateral neck were graded for the presence or absence of 19 cytologic features by two cytopathologists. The cytologic features were analyzed for agreement between observers and underwent multivariate analysis for correlation with the diagnosis of carcinoma.

RESULTS

Interobserver agreement was greatest for increased nuclear/cytoplasmic (N/C) ratio, pyknotic nuclei, and irregular nuclear membranes. Recursive partitioning analysis showed increased N/C ratio, small clusters of cells, and irregular nuclear membranes were the best discriminators.

CONCLUSION

The distinction of branchial cleft cysts from cystic squamous cell carcinoma is cytologically difficult. Both digital image analysis and p16 testing have been suggested as aids in this separation, but analysis of cytologic features remains the main method for diagnosis. In an analysis of 19 cytologic features, we found that high nuclear cytoplasmic ratio, irregular nuclear membranes, and small cell clusters were most helpful in their distinction. Diagn. Cytopathol. 2016;44:561-567. © 2016 Wiley Periodicals, Inc.

Branchial cleft cyst carcinoma: fact or fiction?

PURPOSE OF REVIEW

With the recent changes in the cause of head and neck cancer and the association of cystic metastatic neck squamous cell carcinoma with human papilloma virus (HPV), patients who are diagnosed with a cystic lesion in their upper neck need thorough investigation before commencing any treatment.

RECENT FINDINGS

The differential diagnosis of a cystic mass in the upper neck of an adult over the age of 40 years is a branchial cleft cyst, cystic metastatic squamous cell carcinoma or a branchial cleft cyst carcinoma (BCCC). Investigation must include diagnostic imaging, biopsy or excision biopsy of likely primary sites, such as oropharyngeal sub-sites, and testing for HPV, Epstein-Barr virus immunological status.

SUMMARY

The existence of BCCC is an exceptional diagnosis, with less than 40 cases considered proven. Consensus agreement has been proposed on making such a diagnosis. The diagnosis of a BCCC should be one of exclusion rather than presumption, after all other possible diagnoses have been considered and excluded.