False-negative diagnosis in fine-needle aspirations of squamous-cell carcinoma of head and neck.

Squamous-cell carcinoma (SCC) is the most common malignancy encountered in the head and neck area. Fine-needle aspiration (FNA) is routinely performed in the diagnosis of primary, recurrent, and metastatic SCC. This paper describes several diagnostic problems and pitfalls that might be seen in FNAs of SCC. These include cystic changes, well-differentiated SCC, spindles SCC, and SCC with foreign-body giant cells, keratin plaques, and ghost cells. Recognition of these patterns along with clinical correlation enables the pathologist to prevent a false-negative diagnosis.