Squash Cytology: A Diagnostic Technique in Oral Squamous Cell Carcinoma

Objectives: -To evaluate the diagnostic accuracy of squash cytology in oral squamous cell carcinoma.
-To evaluate the sensitivity and specificity of squash cytology technique.

Methods: After obtaining ethical clearance(SRB/STUG12/44)from Scientific Research Board samples were collected including the controls(n=20). The collected samples were placed in wet gauze piece or wet cotton respectively as the sample should not be stored in formalin.From the resected sample a bit of the tissue was taken and placed on the centre of the slide.A second slide was placed over the sample to form a cross and downward pressure is applied after which the first slide was carefully slide apart. The weight of the spreader slide is sufficient to adequately spread the cells.Squash smear was immediately placed in ethyl alcohol before drying. The slide was then stained with haematoxylin and eosin, dried and mounted.
Results: In comparison to control group, case group showed higher nucleus/cytoplasm ratio. The cytoplasm was observed to be normal in control group and altered cell size was seen in case group. In control group normal morphology of nucleus was observed and in case group large nucleus, increased and abnormal mitotic figures and hyperchromatin granules were seen. Cellular morphology was preserved in both control and case group.The background showed mucinous substance and necrotic substance in case group while only only mucinous substance was observed in the control group.The sensitivity and specificity was analysed by plotting ROC curve.
Conclusions: Squash cytology technique has found its application in general pathology and this is the first of its kind application in oral pathology. The method was fairly accurate and useful for intraoperative diagnosis.Squash cytology offers good details of cellular morphology with a small amount of tissue.Squash cytology is a novel method of diagnosis with potential for further research.