[1101] Levels and P16 Are Valuable Adjuncts in the Evaluation of Cervical Cone or Loop Electrosurgical Excision Procedure (LEEP) Specimens Initially Considered Negative for Dysplasia

Alison B Carrigg, Noel Weidner, Grace Lin, Michael Peterson, Farnaz Hasteh. University of California San Diego Medical Center, San Diego, CA

Background: At University of California San Diego Medical Center an average of 19% of the cervical cone biopsies are negative for dysplasia or malignancy. In order to identify sources of misdiagnosis and error, we evaluated the cause and outcomes of these cervical conization specimens.
Design: Fifty one cone biopsies with an original negative diagnosis were selected at UCSDMC. These specimens and the presurgical Pap smears, biopsies and endocervical curettages (ECC) were reviewed by up to 6 surgical pathologists in order to obtain a consensus diagnosis. Deeper levels and then p16 immunostains were performed on all the cone cases and select biopsy sections.
Results: Please see figure 1.


Conclusions: Our results suggest four categories of cases.
MISSED DYSPLASIA IN CONE SPECIMEN: In 35.3% of cases the original cone diagnosis was overturned to positive (SIL, LSIL or HSIL).
SAMPLING ERROR: For cases with confirmed pre-surgical diagnosis of HSIL but negative cone specimen, 6 of the original 51 cases (11.8%) were found to have dysplasia or even invasive squamous cell carcinoma on subsequent follow-up, suggesting that the conization sampling may have been incomplete due to factors that complicated the surgical procedure.
PRESURGICAL SPECIMEN OVERCALLED AS HIGH GRADE SQUAMOUS INTRAEPITHELIAL LESION (HSIL): In 29.4%, conization was not clinically indicated, due to an overcall of HSIL on the preceding Pap smear, cervical biopsy, or ECC.
PRESURGICAL MATERIAL CONFIRMED AS HSIL, WITH NEGATIVE CONE AND NEGATIVE FOLLOWUP: In 17.6% of cases, no errors were detected in either pre-surgical or conization diagnosis and the patient had negative subsequent follow-up. The implications of this category are unclear, but could result from either incomplete tissue examination, regression of the lesion, or possibly complete excision of small foci of HSIL by biopsy.
Our results, taken as a whole, emphasize the necessity for close clinical follow up, liberal use of p16 immunohistochemistry, examination of deeper level sections, review of prior material, and consensus group review to reduce errors in the pathologic workup of cervical dysplasia.
Category: Gynecologic & Obstetrics

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 130, Wednesday Morning

 

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