Interobserver variability in the interpretation of brush cytologic studies from head and neck lesions.

A study was conducted to evaluate the usefulness of brush cytology as a diagnostic tool for lesions of the head and neck. Brush specimens were obtained from patients for whom surgical biopsy was recommended by the Otolaryngology Service of the University of Texas Medical Branch Hospitals, Galveston. Specimens were interpreted independently by three cytologists, and interobserver variability was calculated. If a surgical biopsy was performed, histopathologic diagnosis was used as the reference standard to assess the accuracy of each cytologic interpretation. Correspondence of cytopathologic interpretation with histologic diagnosis was sufficient to conclude that brush biopsy is a useful screening technique for unsuspected or clinically undetected malignant tumors of the upper aerodigestive tract. Because of its ability to sample large surface areas with minimal tissue trauma, brush biopsy can be a useful screening technique in combination with selective surgical biopsy for the detection of cytologic changes of malignant neoplasia. Brush cytology costs less than surgical biopsy, yet its relatively high sensitivity and specificity for both benign and malignant grades support its utility. Brush cytology, furthermore, has a low interobserver variability for the benign and malignant grades, suggesting that in the hands of an experienced cytopathologist it can be relied on with confidence. For grades 2 or 3 (inconclusive), brush cytology, however, demonstrated much higher interobserver variability. Based on the findings of this and other studies, brush cytology can be effective in identifying clinically unsuspected malignant tumors of the upper aerodigestive tract, especially in patients with mucosal changes suggestive of "field cancerization."

Interobserver variability in the interpretation of fine-needle aspiration biopsy of head and neck masses.

Fine-needle aspiration biopsy is gaining acceptance as a clinically useful tool. We set out to evaluate the accuracy of fine-needle aspiration biopsy at our institution by measuring the interobserver variability in cytopathologic interpretation, and by measuring the agreement between cytopathologic and histologic diagnosis. In a prospective study, 253 aspirations were performed on head and neck masses by the otolaryngology service. Specimens were interpreted independently by two cytopathologists (V.J.S. and P.Z.), and interpretations were compared with the surgical histopathologic diagnosis when available. The interobserver variability between cytopathologists was 8% with a specificity of 96% and a sensitivity of 97%. We conclude that fine-needle aspiration biopsy is a safe and useful tool in the diagnosis of head and neck masses. In the diagnosis of epithelial cysts and squamous epithelial malignancies, fine-needle aspiration biopsy is as accurate as open biopsy.

Olfactory neuroblastoma. Cytodiagnostic features in a case with ultrastructural and immunohistochemical correlation.

In a case of olfactory neuroblastoma, originally misdiagnosed as an undifferentiated carcinoma, cytologic examination of material scraped from the superior nasal vault revealed tumor cells suggestive of neuroblastoma. The most significant cytodiagnostic feature was the presence of a fibrillary cytoplasm with ill-defined borders. Also noteworthy were the smudged hyperchromatic nuclei and structures resembling rosettes or pseudorosettes. The diagnosis was confirmed by electron microscopy, which revealed the presence of dense-core neurosecretory granules, clear vesicles, neurotubules and neurofilaments, and by immunohistochemistry, which showed positive staining for neuron-specific enolase but negative staining for keratin and glial fibrillary acidic protein. Since olfactory neuroblastoma has a relatively good prognosis and aggressive surgical resection may be curative, it is important that this tumor be distinguished from other small cell malignancies arising in the nasal cavity. The present case shows that the diagnosis can be made by the cytologic examination of scrapings from the tumor.