Abstract
Objective : Even after the adoption of the Bethesda System (TBS) 2001 in Japan, distinction between “atypical squamous cells of undetermined significance (ASC-US)” and other categories is still problematic in some cases.
Study Design : We subdivided ASC-US in TBS 2001 into “ASCUS not otherwise specified (ASCUS-NOS),” characterized by slight atypia, but not highly suspicious of dysplasia, and “ASCUS favoring dysplasia (ASCUS-D),” characterized by a picture suspicious of dysplasia. We compared cases of ASCUS-NOS and ASCUS-D, especially in terms of the rates of human papillomavirus (HPV) infection and the histological diagnoses.
Result : Among 14655 cytology specimens obtained by Cervex Brush (Rovers), 354 (2.4%) were labeled as ASCUS-NOS and 150 (1.0%) as ASCUS-D. Of the 115 ASCUS-NOS cases analyzed for HPV, 22 (19.1%) were HPV-positive, and of the 61 ASCUS-D cases analyzed for HPV. 33 (54.1%) were HPV-positive. Histologically, 47 of the 52 HPV-positive ASC-US cases (90.4%) were diagnosed as dysplasia.
Conclusion : It is possible to subdivide ASC-US cases into ASCUS-NOS and ASCUS-D categories, which associated with rather different HPV-positive rates. We believe that it is important to be aware of this subclassification of ASC-US for improving of our diagnostic skills.
