Evaluation of atypical squamous cells on conventional cytology smears: An experience from a screening program practiced in limited resource settings.
BACKGROUND
The Bethesda system (TBS) 2001 has subdivided the category of atypical squamous cells (ASC) into: ASC-US (undetermined significance) and ASC-H (cannot exclude high-grade squamous intraepithelial lesion (HSIL)). The present study is an analysis of ASC-US and ASC-H cases diagnosed in a screening program practiced in limited resource settings.


METHODS
During the period January 2005 to December 2008, a total of 9190 smears were received, of which 568 were unsatisfactory. Cases initially diagnosed as ASC-US (n=74) and ASC-H (n=29) on conventional cytology smears were reviewed. Biopsy and human papilloma virus (HPV) results were available in limited cases.


RESULTS
On review, diagnosis of ASC-US was retained in 49 (66.2%) of the 74 initially diagnosed ASC-US cases. Remaining 12 cases were re-labeled as negative for intraepithelial lesion or malignancy (NILM), nine as low-grade squamous intraepithelial lesion (LSIL), three as ASC-H and one case as squamous carcinoma (SCC). Similarly, on review, diagnosis of ASC-H cases was retained in 17 of the 29 initially diagnosed ASC-H cases. Seven cases were re-labeled as NILM, three as HSIL and one case each as ASC-US and SCC. Overall, 8622 cases (96.6%) were diagnosed as NILM, 72 (0.83%) as LSIL, 121 (1.40%) as HSIL, 23 (0.26%) as SCC, 50 (0.57%) as ASC-US cases, 20 (0.23%) as ASC-H, five (0.05%) as atypical glandular cells (AGC) and two cases as adenocarcinomas. Out of 50 ASC-US cases, biopsy in 23 cases showed presence of CIN 1 in 16 cases (69.5%) and CIN 2 in one case (4.34%), while the remaining six cases were negative for CIN/malignancy. The remaining 20 cases with unavailable biopsy results were HPV-positive. Out of 20 ASC-H cases, biopsy in 15 revealed CIN 2 and above in 11 cases (73.3%). Three cases (20%) revealed CIN 1.


CONCLUSIONS
Critical review is helpful in further reducing the number of ASC cases. The percentage of cases with CIN 2 and above is higher with ASC-H cases. The reason for relative increase in HSILs in the present study included referral bias in the screening program.
Rekhi
Bharat
B
Department of Surgical Pathology, Tata Memorial Centre, Parel, India.
Ajit
Dulhan
D
Joseph
Santhosh K
SK
Gawas
Sonali
S
Deodhar
Kedar K
KK
Diagn Cytopathol. 2003 Jun;28(6):308-12
12768635
N Engl J Med. 2009 Apr 2;360(14):1385-94
19339719
Acta Cytol. 1997 Nov-Dec;41(6):1697-700
9390126
J Med Screen. 2004;11(2):77-84
15153322
Am J Obstet Gynecol. 2003 Jun;188(6):1383-92
12824967
Acta Cytol. 2001 Jul-Aug;45(4):493-8
11480707
Bull World Health Organ. 2005 Mar;83(3):186-94
15798842
Am J Clin Pathol. 1995 May;103(5):594-7
7741105
Am J Clin Pathol. 1999 Jul;112(1):57-62
10396286
Indian J Pathol Microbiol. 2009 Jan-Mar;52(1):34-7
19136776
Int J Gynaecol Obstet. 2006 Nov;95 Suppl 1:S215-S233
29644660
Diagn Cytopathol. 2003 Jul;29(1):38-41
12827715
JAMA. 2002 Apr 24;287(16):2120-9
11966387
Diagn Cytopathol. 2007 Nov;35(11):677-80
17924415
JAMA. 1994 Jun 15;271(23):1866-9
8196145
J Cytol. 2009 Apr;26(2):69-73
21938156
Br J Gen Pract. 1991 May;41(346):188-91
1878268
Am J Clin Pathol. 2001 Sep;116(3):386-94
11554167
JAMA. 2002 Apr 24;287(16):2114-9
11966386