1. Himalayan Institute of Medical Sciences
Accuracy of intra-operative rapid diagnosis by Squash smear in CNS lesions – An early institutional experience.
KK Bansal,
Monika Bansal, Sanjeev Kishore, Anuradha K, Meena H, Dushyant G.
Department of Neurosurgery & Pathology
Himalayan Institute of Medical Sciences
Dehradun, India.

2. Introduction
Squash smear preparation - fairly accurate, simple and reliable tool for rapid intra-operative diagnosis of central nervous system lesions.
Based on two essential factors:
Availability of very small tissue fragments & good preservation of fine cellular details.
Not effected by edema, hemorrhage, necrosis & calcification.
Compared with frozen sections, this technique has the advantage of being both more accurate for cytological details and of requiring less tissue.

3. Surgery is easy in such cases ---------but

4. Here – where ICA encased & infiltrating tumor, Surgical challenge..

5. Material and Methods Prospective study Included 118 patients
Period of October October 2006.
All patients operated for CNS mass lesions were included
Squash cytology reported by pathologists
All were subjected for routine histopathological processing.

6. Squash smear technique

7. Minimum 2 air dried & 4 wet smear ( MGG, H & E, PAP Stain).

8. Age wise distribution

9. Sex wise distribution

10. Site wise distribution of CNS lesions (n=118)
S.No Site No. of Tumors Percentage (%)
Cerebral Hemisphere
-Frontal
-Parietal
-Temporal
-Overlapping lesions
2. Cerebellum
3. Pineal region
4. Ventricles
5. Suprasellar region
6 Cerebellopontine angle
7. Spinal cord
8. Non-Specific
Total

11. Distribution of cases based on clinical diagnosis (n=118)
S. No. Clinical / Provisional Diagnosis No. of cases Percentage
1 Glioma
2 Pituitary adenoma
3 Craniopharyngioma
4 Meningioma
5 Schwannoma
6 Neurofibroma
7 Metastatic
8 Epidermoid cysts
9 Arachnoid cysts
10 Vascular lesion
11 Tuberculosis
Seizure related lesion
13 Nonspecific diagnosis
Others
Total

12. Distribution of cases based on intraoperative squash smear cytologic diagnosis (n=118)
S. No. Cytopathological Diagnosis No. of cases Percentage
1 Glioma
-Astrocytoma
-Glioblastoma Multiforme
-Oligodendroglioma
-Ependymoma
2 Pituitary adenoma
3 Craniopharyngioma
4 Meningioma
5 Schwannoma
6 Neurofibroma
7 Metastatic tumors
8 Tuberculosis
9 Aspergillosis
10 Others
Total

13. Distribution of cases based on Histopathologic diagnosis (n=118)
S. No. Histopathological Diagnosis No. of cases Percentage
1 Glioma
-Astrocytoma
-Glioblastoma Multiforme
-Oligodendroglioma
-Ependymoma
-Gliosarcoma
2 Ganglioglioma
3 Pituitary adenoma
4 Craniopharyngioma
5 Meningioma
6 Schwannoma
7 Neurofibroma
8 Metastatic
9 Tuberculosis
10 Aspergillosis
11 Seizure related lesion
12 Other
Total

14. Cyto-histological correlation of CNS lesions (n=118)
S. No Cytological Diagnosis No. of Cases Histological Diagnosis No. of Cases Percentage
1 Glioma / Astrocytoma Astrocytoma
Glioblastoma
Oligodendroglioma
Ependymoma
Ganglioglioma
2 Glioblastoma Multiformae Glioblastoma
Gliosarcoma
3 Ependymoma Ependymoma
Ganglioglioma
4 Pituitary Adenoma Pituitary Adenoma
5 Craniopharyngioma Craniopharyngioma
6 Meningioma Meningioma
Ependymoma
Gliosarcoma
7 Schwannoma Schwannoma
Meningioma
8 Neurofibroma Neurofibroma
Meningioma
9 Metastatic Metastatic
10 Tuberculoma Tuberculoma
11 Aspergillosis Aspergillosis
Others
Total

15. Conclusion
The cytohistological correlation of all 118 lesions diagnosed on cytology was 89.7%.
Common reasons for no opinion on cytology were fibrosis, inflammation, calcification, necrosis and lack of definite cytologic criteria.

16. Common causes for erroneous diagnosis on cytology were
increased fibrous component,
biopsy from cyst wall,
increased and morphology obscuring inflammation and necrosis,
lack of architecture on cytology,
reactive changes,
resistance to desegregation.

17. Pilocytic Astrocytoma

18. Astrocytoma grade 2

19. Astrocytoma grade 3

20. Astrocytoma grade 4

21. Astrocytoma grade 4

22. Ependymoma

23. Meningioma

24. Psammomatous Meningioma

25. Metastatic lesion

26. Bronchogenic cyst

27. Granulomatous lesion

28. Aspergilloma

29. THANK YOU