RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES
KARNATAKA, BANGALORE
ANNEXURE II
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1. / NAME OF THE CANDIDATE & ADDRESS / DR. INDRANI.K
POST GRADUATE STUDENT MD PATHOLOGY SDM COLLEGE OF MEDICAL SCIENCES AND HOSPITAL, DHARWAD – 580009
2. / NAME OF THE INSTITUTION / SDMCOLLEGE OF MEDICAL SCIENCES AND HOSPITAL, DHARWAD – 580009
3. / COURSE OF STUDY AND SUBJECT / MD PATHOLOGY
4. / DATE OF ADMISSION TO THE COURSE / 31ST MAY 2011
5. / TITLE OF TOPIC / SQUASH CYTOLOGY OF CNS LESIONS.
6. / BRIEF RESUME OF THE INTENDED WORK:
6.1 Need for study:
Intraoperative consultation for CNS lesions is frequently sought to ensure proper sampling of the lesion tissue. It is of value to the neurosurgeon if an unexpected lesion is encountered during surgery or when the appearance of lesion seen during surgery is different from that visualised preoperatively.1
Intraoperative consultation is asked for by the neurosurgeon mostly in cases of dilemma regarding the diagnosis being neoplastic or infectious. If there is an infectious process, an additional sample has to be sent for microbiological examination and also post-operative intensive antibiotic treatment needs to be started. In case of a neoplastic lesion, the type of neoplasm, as to that amenable to thorough surgical resection only or those requiring additional chemotherapy and radiotherapy as well, can be determined besides proving if the tumour is a primary or metastases from a distant site.2
Squash preparation is an adjuvant in diagnosing CNS lesions on tissue sent for frozen section. Crush smear cytology better suits CNS lesions than any other tumours because of scanty connective tissue in the CNS. Most of the lesions are solid and creamy. Therefore a comparative analysis is being done between squash preparation and regular histopathological examination, with an aim to identify the advantages of using squash studies along with frozen sections for intraoperative diagnosis.
6.2 REVIEW OF LITERATURE:
Intraoperative cytology preparation was first introduced by Eisenhardt and Cushing in early 1930’s and by Badt in 1937. This technique was further championed and documented by Russel et al, in 1937. The present technique was introduced by her along with Sir Hugh Cairns in 1930’s .3
The goal of a neuropathologist in an intraoperative setting is to diagnose and provide sufficient preliminary information to optimize the surgical management of the patient. The difficulties in accessing and fragile nature of CNS tissue are the main limitations in arriving at an almost definitive diagnosis in CNS lesions. The inherent soft nature of brain tissue and high water content render poor quality frozen sections. Thus arises the need for an alternative method for more conclusive opinion and squash preparation can be efficiently used to overcome this limitation.4
Also the volume of tissue sent by neurosurgeon is sometimes scanty, more so because CT and MRI guided stereotactic biopsies are gaining importance these days and squash preparation requires lesser tissue, thus preserving tissue for paraffin sections, marker studies, special stains and PCR.5
Squash preparation is an effective, simple, rapid and reliable technique for diagnosis of CNS lesions. The knowledge of this technique is beneficial in centers where facility for frozen section is unavailable or in case of power breakdown or lack of trained technical personnel.4 Squash preparation is also of importance in processing samples from patients of AIDS and slow virus diseases, considering the contamination of instruments used by fresh unfixed tissues.10 Thus squash preparation serves as a valuable diagnostic tool in experienced hands.
Majority of the CNS lesions have characteristic cytomorphological appearance which helps in definitive diagnosis of these lesions on smear preparation. However accuracy of diagnosis on cytology depends on familiarity with the clinical history, tumor location, differential diagnosis of lesions in a particular location and etiologies of CNS mass lesions besides the knowledge and experience of neuropathologist in the field of CNS cytology.5
Squash preparation better preserves the cytological details which aid in diagnosis and are obscured at times in frozen sections.6 However tissue architecture is preserved in frozen sections.7 Therefore recent studies have advocated the addition of cytologic touch imprints and squash preparations to traditional frozen section to improve diagnostic accuracy of CNS lesions.8
Many studies have been undertaken to prove the utility of squash preparation in diagnosing CNS lesions. Ghoshal et al conducted a retrospective study of 306 cases where smear preparation findings of intracranial lesions were compared with their histopathological diagnosis and cytohistological correlation was seen in 93% cases. Cytomorphology of few new entities of CNS lesions were described in this study.8 A similar study by Pawar NH et al suggested a diagnostic accuracy of 88%, sensitivity of 91.6% and 100% specificity and positive predictive value.3 A study by Scucchi et al showed a diagnostic accuracy of 99.2% on combining intraoperative cytology and frozen section studies. Thiswas higher than that reported on frozen section preparation alone. In 113 cases where frozen section was not diagnostic, cytology gave a specific diagnosis.10 Rossler et al studied 4172 cases; Cytohistological correlation was achieved in 89.8%, increased to 95% when cases with partial correlation, mainly due to grading deviations were included.9
Intraoperative cytologic smears in neurosurgery are easy to perform and
inexpensive and permit high diagnostic accuracy. This allows reliable
intraoperative diagnoses and guidance during targeting and resecting lesions in
oncologic neurosurgery.9
6.3 Objectives of study:
1) To study the cytology of various CNS lesions by squash technique.
2) To assess the utility of squash preparation, as an aid to frozen section study.
3) To assess the accuracy of squash preparation, by comparing it with histopathological section.
7. / MATERIALS AND METHODS:
7.1 Source of data:
It is both prospective and retrospective study of 3 1/2 years duration, done in SDM College of Medical sciences and hospital, Dharwad.
Retrospective study- from 1st June 2009 to 1st June 2011.
Prospective study- from 2nd June 2011 to 30th January 2013.
Neurological specimen received in the department of pathology for frozen section will be studied. Squash preparation is done on all the cases and stained with H & E staining. An intraoperative diagnosis is made on squash preparation and frozen section slides. The diagnosis on squash smears will be compared with the final diagnosis given on paraffin embedded histopathological sections. The sample size may be 50-100 cases for the entire duration of study.
Inclusion Criteria:
Cases where surgical specimen sent freshly without any fixative, for frozen section will be included in the study.
Exclusion Criteria:
Those cases in which specimen are sent in fixative, to the department will be excluded from the study.
7.2  Methods of collection of data:
1) Preoperatively, clinical details of the patient like age, sex, symptoms and signs on presentation, clinical diagnosis along with other relevant clinical and radiological findings will be noted.
2) Tissue sent for intraoperative consultation will be used for squash preparation
that is, one to two millimeters of tissue is crushed between two slides in order to spread the tissue into a thin film, fixed in 95% alcohol and stained by H & E.
3) Cytomorphological findings will be observed on squash preparation.
4) The findings observed on cytology smears will be compared with those present in the paraffin embedded sections.
7.3 Does the study require any investigation to be conducted on patients or animals? If so please describe briefly.
Yes. The study involves the study of histological features described in 7.2. An informed consent is taken from the patients during procedure.
7.4  Has ethical clearances been obtained from ethical committee of your institution in case of 7.3?
Yes. Ethical clearance has been obtained from the SDM Institutional Ethical committee. SDM Medical college, Dharwad.
8. / LIST OF REFERENCES:
1)  Ironside JW, Moss TM, Louis DN, Lowe JS, Weller RO. Diagnostic pathology of nervous system tumours. Philadelphia:Elselvier Churchill Livingstone;2002.p 41-51.
2)  Perry A, Brat DJ. Practical surgical neuropathology- a diagnostic approach. Philadelphia:Elselvier Churchill Livingstone;2010.p 35-45.
3)  Pawar HN, Deshpande AK, Surase SG, Dcosta GF, Balgi SS, Goel AD. Evaluation of squash smear technique in the rapid diagnosis of CNS tumours: A cytomorphological study.The internet journal of pathology 2010;11(1).
4)  Rao S, Rajkumar A, Ethesham MD, Duvuru P. Challenges in neurosurgical intraoperative consultation. Neurology India 2009;57(4):p 464-68.
5)  Iqbal M, Azra S, Wani MA, Kirmani A, Ramzan A. Cytopathology of CNS. Part I- Utility of crush smear cytology in intraoperative diagnosis of CNS lesions.Acta Cytologica 2006 ;50(6):p 608-16.
6)  Savargaonkar P, Farmer PM. Utility of intraoperative consultations for the diagnosis of CNS lesions.Annals of clinical and laboratory science 2001;31(2):p 133-39.
7)  Plesec TP, Prayson RA. Frozen section discrepancy in the evaluation of CNS tumours. Archives of pathology laboratory medicine 2007;131:1532-40.
8)  Ghoshal N, Hegde AS, Murthy G, Furtado SV. Smear preparation of intracranial lesions: A retrospective study of 506 cases. Diagnostic cytopathology 2010;39(8):p 582-92.
9)  Rossler K, Dietrich W, Kitz K.High diagnostic accuracy of cytologic smears of CNS tumours. A 15- year experience based on 4172 patients. Acta cytologica 2002;46(4):p 667-74.
10) Scucchi LF, Stefano DD, Cosentino L, Vecclione A. Value of cytology as an adjunctive intraoperative diagnostic method- an audit of 2250 consecutive cases.Acta cytologica 1997;41(5):p 1489-96.
9. / Signature of the Candidate
10. / Remarks of the Guide
/ Information, the pathologist get by meticulous study of squash smears of CNS lesions is precious. Squash smears not only help the neurosurgeon about appropriate biopsy of the lesion but also aids in diagnosis within the critical time period. Thorough training of pathology scholars for this technique is necessary. Such an attempt is planned in the present thesis.
11. / NAME & DESIGNATION
11.1 GUIDE / DR. ANEEL MYAGERI MD
ASSOCIATE PROFESSOR,
DEPARTMENT OF PATHOLOGY,
SDMCMSH, DHARWAD
11.2 SIGNATURE
11.3 CO-GUIDE / -
11.4 SIGNATURE / -
11.5 HEAD OF THE DEPARTMENT / DR. RAVIKALA RAO MD
PROFESSOR & HEAD,
DEPARTMENT OF PATHOLOGY,
SDMCMSH, DHARWAD
11.6 SIGNATURE
12. / 12.1 REMARKS OF CHAIRMAN
AND PRINCIPAL
12.2 SIGNATURE