The cytological evaluation of the TIC revealed 12, 16 and two cases as benign, malignant and suspicious for malignancy, respectively. Further histological examination of the permanent sections revealed 15 cases each as malignant and benign lesions. The concordance between touch imprint and paraffin sections was 90% (27 of 30). The sensitivity and specificity of TIC in detecting malignancy were 88% and 92%, respectively (Table 1). These high rates highlight the value of TIC as a relatively simple technique that can allow the pathologist to render an intraoperative diagnosis. In addition, TIC is less expensive than the frozen section method. The disadvantages of the TIC method are that it does not provide architectural information and it cannot distinguish between in situ and invasive lesions. The cytological diagnosis suspicious for cancer was encountered in two cases. In these two cases, cellularity was lacking, and many bare nuclei and benign cell clusters were present. The cases suspicious for malignancy were negative on further permanent histological sections. We propose the necessity of maintaining this diagnostic category for two reasons. First, it allows the cytologist to raise the suspicion of malignancy in a mass lesion that does not meet all the TIC criteria for malignancy. Secondly, this diagnostic category helps keep false-positive diagnoses near zero. The false-negative cases in our series (two cases) may be inherent in the procedure. With further analysis of these cases, the missed diagnosis could have been averted by careful screening to detect scant malignant cells. In frozen sections, many factors contribute to the false-negative rate, including the suboptimal preparation of the specimen and sampling errors [5]. Our results indicate that TIC can overcome its deficits, and proved useful in evaluating head and neck mass lesions (nasal, pharyngeal, laryngeal and oral lesions).
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Departments of 1 Pathology, 2 Ear, Nose and Throat, and 3 Maxillofascial, Head and Neck Surgical Unit, Department of Surgery, Assuit and South Valley Universities Schools of Medicine, Egypt
* Email: mrh17{at}swissinfo.org
Acknowledgements
This work was supported by research fund from the Department of Pathology, School of Medicine, Assuit, Egypt.
Notes
(Former address: Medical School, University of Wiscornsin and William S. Middleton Memorial Veteran Hospital, Madison, WI 53705, USA)
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