How Much Is Enough? Adequacy in Pap Tests after Hysterectomy and Radiation.
Irene A Czyszczon, Lynn P Parker, Houda Alatassi. University of Louisville, KY
Background: We identified a number of patients with unsatisfactory Papanicolaou (Pap) tests (UPTs) despite multiple aggressive scapula scrapings. These patients tended to be older and post hysterectomy and radiation/chemotherapy. The 2001 Bethesda System minimal criteria for a satisfactory Pap from liquid-based preparation is 5000 well-visualized/well-preserved squamous cells. In cases of post hysterectomy, however, Bethesda states,“laboratories should exercise judgment in reporting cellularity based on the clinical and screening history,” and “lower cellularity may be acceptable under these circumstances.” No minimum cellularity has been proposed by Bethesda or in the literature, and we propose a number to standardize adequacy reporting in these patients.
Design: We searched our data for patients >40 years old with ThinPrep UPTs from January 2007 to January 2009 and recorded demographics, clinical diagnoses, and history of hysterectomy and radiation/chemotherapy. Vaginal samples were collected using a cytobrush/spatula, rinsed in PreservCyt transport medium, and processed by ThinPrep T2000 processor (Cytyc Corporation, Marlborough, MA). UPTs with subsequent negative for intraepithelial lesion (NIL) on follow-up were studied to determine cellularity.
Results: 4019 Paps were performed on women >40 years of age over 2 years, 98 (2.4%) of which were unsatisfactory. 27/98 (28%) patients had previous hysterectomy and radiation/chemotherapy for gynecological malignancy. 23/27 (85%) had insufficient cellularity and 4/27 (15%) were obscured by blood or inflammation. 24 (89%) patients had follow-up Paps. 20 (83%) were diagnosed as NIL, 2 (8.7%) unsatisfactory, and 2 (8.7%) ASC-US. Cellularity varied considerably, ranging up to 3000 epithelial cells per slide.
Conclusions: Prior studies have shown that UPTs carry a higher risk of significant histologic abnormalities on follow-up than negative satisfactory Paps. However, these studies did not exclusively investigate our specific patient population, rather examined all Paps performed. Our study showed a low incidence of abnormal follow-up findings. Bethesda minimum criteria (5000 cells) for cervical cytology can be difficult to reach in instances of advanced age, total hysterectomy, and chemo or radiation treatment. Our results show that fewer epithelial cells can be considered adequate, and immediate repeat pap tests are unnecessary. A minimum cellularity should be set in order to reduce variability among evaluations of adequacy, and we propose 2000-3000 cells should be adequate in this population.
Tuesday, March 1, 2011 9:30 AM
Poster Session III # 103, Tuesday Morning