Cytology in the otorhinolaryngologist’s domain - a study of 150 cases, emphasizing diagnostic utility and pitfalls

Abstract

150 patients with mass lesions in the head and neck area, excluding the CNS and thyroid gland were subjected to FNA cytodiagnosis. II out of 150 smears were considered unsatisfactory for diagnostic evaluation. Out of the 139 patients who yielded satisfactory smears, cytodiagnosis led to the following broad categories - inflammatory and non- neoplastic (24/139, 17.3%), benign neoplasm (60/139, 43.2%), suspicious for malignancy (14/139. 10%) and malignant neoplasms (41/139, 29.5%). Histopathologic follow- up was available in 120 cases. 15/24 with inflammatory lesions were not subjected to biopsy, rest 4 were lost to follow up (I had a suspicious smear and 3 the diagnosis of benign neoplasm). Correlation of cytodiagnoses with histopathology yielded the following results - 52 out of 57 patients with the cytodiagnosis of benign neoplasm and having, histologic follow up had concordance, while 39 out of 41 cytologic diagnoses of malignancy, correlated with histopathology.

Out of surgically sampled 9 patients, with inflammatory smears, 8 were benign and 1 malignant. In the suspicious category 2 out of 13 surgically sampled patients had malignancy. Thus, excluding the suspicious smears the accuracy of diagnosis by FNAC in this study came to 93% and a sensitivity for cancer detection of 95%. We encountered a false negative rate of 9.0% and a false positive rate of 4.9%.

The results are discussed, especially in the light of the misdiagnoses and ways at avoiding diagnostic : error.