A situation generally dismissed as benign by pathologists and gynecologists alike is the clinically/sonographically thin endometrium that affords a paucicellular, essentially nondiagnostic (informatively noninformative) tissue specimen. Normal postmenopausal endometrium is grossly thin and microscopically inactive and oftentimes (in up to 50% of samplings) yields no tissue, but the corollary that grossly thin (sonographically <5-mm thickness) postmenopausal endometrium is microscopically inactive and uniformly benign may be false. Endometrial suction biopsy has a reasonable sensitivity and specificity for detecting symptomatic endometrial cancer in thickened endometrium. However, few data are available regarding its sensitivity and specificity among asymptomatic postmenopausal women.
While it is well understood that every endometrial cancer has a precursor state, the assumption that the precursor of endometrial carcinoma, similar to hyperplasia, must be diffuse and symptomatic is false. Theoretically, the cells of an endometrial precancer should be genetically different from normal endometrium yet should share some but not all the features of malignant endometrium. Precancerous endometrial cells should be neoplastic (Table 8.1) and demonstrate a monoclonal growth pattern and clonally distributed (geographically clustered) mutations. Progression of endometrial precancer to carcinoma, effectively a conversion from a benign neoplasm to a malignant neoplasm, would be expectedly accomplished through the acquisition of additional mutations and accompanied by a change in biological behavior most notably characterized by the ability of outspoken cancer cells to invade local tissues and to metastasize.
KeywordsEndometrial Cancer Endometrial Carcinoma Clear Cell Carcinoma Serous Carcinoma Endometrial Hyperplasia
- Baak JP, Mutter GL, Robboy S, van Diest PJ, Uyterlinde AM, Orbo A, Palazzo J, Fiane B, Løvslett K, Burger C, Voorhorst F, Verheijen RH. The molecular genetics and morphometry-based endometrial intraepithelial neoplasia classification system predicts disease progression in endometrial hyperplasia more accurately than the 1994 World Health Organization classification system. Cancer (Phila) 2005; 103: 2304–12.CrossRefGoogle Scholar
- Bergeron C, Nogales FF, Masseroli M, Abeler V, Duvillard P, Müller-Holzner E, Pickartz H, Wells M. A multicentric European study testing the reproducibility of the WHO classification of endometrial hyperplasia with a proposal of a simplified working classification for biopsy and curettage specimens. Am J Surg Pathol 1999; 23: 1102–8.PubMedCrossRefGoogle Scholar
- Korhonen MO, Symons JP, Hyde BM, Rowan JP, Wilborn WH. Histologic classification and pathologic findings for endometrial biopsy specimens obtained from 2964 perimenopausal and postmenopausal women undergoing screening for continuous hormones as replacement therapy (CHART 2 Study). Am J Obstet Gynecol 1997; 176: 377–80.PubMedCrossRefGoogle Scholar
- Maksem JA, Lee SS, Roose EB, Carlson JA, Dornbier DP, Belsheim BL. Rare epithelial sheets with “cancer-like” nuclei presenting against a background of cytologically normal-appearing endometrial epithelium in endometrial brush samplings: establishing a differential diagnosis. Diagn Cytopathol 1999; 21: 378–86.PubMedCrossRefGoogle Scholar
- Mutter GL, Duska LR, Crum CP. Endometrial intraepithelial neoplasia. In: Crum CP, Kenneth RL, eds. Diagnostic Gynecology and Obstetric Pathology. Elsevier Saunders, Philadelphia, PA, p. 500, fig.17.4, 2006.Google Scholar
- Mutter GL, Zaino RJ, Baak JP, Bentley RC, Robboy SJ. Benign Endometrial Hyperplasia and EIN Pathology of the Female Reproductive Tract. Elsevier, Churchill Livingstone, London, 2nd edn, p. 1045, 2009.Google Scholar
- Norimatsu Y, Shimizu K, Kobayashi TK, Moriya T, Tsukayama C, Miyake Y, Ohno E. Cellular features of endometrial hyperplasia and well differentiated adenocarcinoma using the Endocyte sampler: diagnostic criteria based on the cytoarchitecture of tissue fragments. Cancer (Phila) 2006; 108: 77–85.CrossRefGoogle Scholar
- Shapiro S, Kelly JP, Rosenberg L, Kaufman DW, Helmrich SP, Rosenshein NB, Lewis JL Jr, Knapp RC, Stolley PD, Schottenfeld D. Risk of localized and widespread endometrial cancer in relation to recent and discontinued use of conjugated estrogens. N Engl J Med 1985; 313: 969–72.PubMedCrossRefGoogle Scholar
- Shu YJ, Ikle FA. Cytopathology of the Endometrial Cancer. McGraw-Hill, New York, 1992.Google Scholar