Histopathologic and Cytopathologic Diagnostic Discrepancies in Head and Neck Region: Pitfalls, Causes, and Preventive Strategies

Abstract

Clinicians commonly utilize fine needle aspiration biopsy (FNAB) for the primary investigation of head and neck masses. Correlation of these results with the surgical resection diagnosis is an essential part of quality control and assurance programs in all cytology laboratories. Of 610 cases, 20 (3.3%) had corresponding surgical resections performed within 3 months of the FNAB, with a discrepant diagnosis identified through a search that involved all FNABs performed on the head and neck region, excluding the thyroid gland, at Wayne State University between 1999 and 2004. Sites of discrepant samples included the parotid or submandibular gland (n = 5), lymph nodes (n = 8), and paratracheal/paraesophageal neck masses (n = 7). The reasons of false-negative FNABs included sampling errors (n = 3), insufficient material for an adequate interpretation (n = 5), lack of triage necessary for ancillary studies (n = 4), and interpretation errors (n = 6). There were 2 false-positive FNABs, both reported as mucoepidermoid carcinoma and showed chronic sialadenitis in one and lymphoepithelial cyst in the other. FNAB is an effective tool for the diagnosis and triage of patients with head and neck masses that can be further improved with an onsite immediate adequacy evaluation and triage performed by a pathologist.