Glioblastoma multiforme was misdiagnosed twice as metastasic carcinomas,
and high grade astrocytoma was misdiagnosed five times as metastasic carcinomas. Two cases of astrocytoma grade I was misdiagnosed as metastasic carcinomas, and one case of meduloblastoma was misdiagnosed as meningioma. Other misdiagnosed tumors were reported as benign or malignant microscopic results or inflammation (figure 1-6). Discussion The present study was a retrospective analysis to determine the accuracy of touch preparation technique in diagnosing the type of tumors encountered Inhibitors,research,lifescience,medical during the operation. This technique is reliable, simple, and accurate. Different authors used various stains such as 1% alcoholic toluidine blue and May-Grunwald–Giemsa.3,4 We, however, Inhibitors,research,lifescience,medical used Giemsa and papanicolau. Compared to frozen section, in touch preparation technique and a large area of tissue can be examined. Besides, touch preparation technique provides
enough tissue for intraoperative and subsequent routine paraffin section diagnoses. The two techniques are complementary, but frozen section is a better technique for the tissues, which their consistency is confirmed.5 Unlike Inhibitors,research,lifescience,medical permanent histology, the frozen section technique, which has the accuracy rate of about 97%, can be done during the surgery. However, cryostat facility is not available at many centers in Iran. Touch preparation technique provides more crisp cytologic Inhibitors,research,lifescience,medical detail than frozen sections
do, and can avoid most of freezing artifacts in brain tumors, high lipid content and soft nature.6 Frozen section is a Selleck BLZ945 reliable method for intraoperative consultation during surgery. The use of frozen section during surgery can give the surgeon the opportunity to avoid the second surgery. Touch preparation technique is a reliable Inhibitors,research,lifescience,medical method for intraoperative evaluation as well. Due to high predictive value, the touch technique can be used first in the operation room, and frozen section can be saved for cases with inconclusive diagnosis by the touch technique.7 Isotretinoin This study is one of the largest studies of this technique on CNS tumors in Iran. Our findings are similar to those of other studies (table 2).4,5,9,10 Previous reports indicate that the diagnostic accuracy of cytological smears ranged from 75% to 94%.15,23 In the present study the accuracy of touch preparation technique in diagnosing brain lesions was 84%, which is lower than that of other studies that included tumors only. This may be to the inclusion of other types of tumor such as bone tumors in the studies of neurosurgical tumors. The low diagnostic accuracy of touch preparation technique in our study may be related to limited sample size. Table 2: Diagnostic accuracy of central nervous system lesions from a number of published studies.