Biopsy findings in five hundred thirty-one patients with atypical glandular cells of uncertain significance as defined by the Bethesda system.

Objectives: Histologic findings in biopsy specimens obtained from patients with atypical glandular cells of uncertain significance were studied to define the utility and limitations of this category.
Study Design: Computerized records over a 3-year period were retrospectively analyzed. The most significant histologic diagnosis from all biopsy specimens submitted was compared with the subcategory of the first Papanicolaou smear obtained showing atypical glandular cells of uncertain significance.
Results: Biopsy results were available for 531 of 1117 patients with atypical glandular cells of uncertain significance (48%). Biopsy-proved preinvasive (83%) or invasive (17%) lesions were present in 191 patients (36%). Eighty-nine percent of the preinvasive lesions were squamous, whereas 97% of the invasive lesions were glandular. Glandular lesions were more likely to be invasive, whereas squamous lesions were more likely to be preinvasive (p < 0.001). Twenty-eight patients had endometrial carcinoma, which represents 88% of all invasive carcinomas detected.
Conclusions: Almost three fourths of patients with atypical glandular cells of uncertain significance and with lesions have squamous lesions, not glandular as suggested by the name of the category. Unlike patients with atypical squamous cells of uncertain significance, patients with atypical glandular cells of uncertain significance have a significant risk of malignant lesions, which are nearly all glandular and predominantly arise from the endometrium.