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  • Print publication year: 2012
  • Online publication date: July 2013

7 - Endometrioid adenocarcinoma



Endometrioid adenocarcinomas, which comprise approximately 85% of all endometrial cancers, are the most common type of endometrial carcinoma and the most commonly diagnosed gynecologic cancer in North America. Despite the high prevalence of this tumor type, the vast majority of affected patients can be cured without chemotherapy. Endometrioid adenocarcinomas are considered type I endometrial cancers according to the Bokhman classification because of their epidemiologic association with estrogen. The current model of estrogen-dependent endometrial carcinogenesis involves progression from hyperplasia, with increasing degrees of architectural and cytologic atypia (complex atypical hyperplasia). The development of an invasive neoplasm heralds the emergence of “adenocarcinoma” in this context. These generalities pertain mostly to differentiated endometrioid adenocarcinomas, grades 1 and 2 in the FIGO system.

In practice, endometrioid adenocarcinoma is often a default diagnosis for carcinomas of the endometrium. As these tumors occur rather frequently, the default leads to correct diagnosis in most cases. The shotgun approach is, in fact, fairly accurate when the tumor is differentiated and exhibits low nuclear grade; however, this approach is often inaccurate in tumors with high nuclear grade and those demonstrating solid architecture. Tricky diagnostic challenges exist at both ends of the differentiation spectrum. Meaningful criteria that separate hyperplasia and adenocarcinoma are still being debated, as are those that distinguish gland-forming endometrioid adenocarcinoma and serous carcinoma, and clear cell carcinoma in some cases.

Bokhman, JV.Two pathogenetic types of endometrial carcinoma. Gynecol Oncol 1983;15(1):10–17.
Soslow, RA, Bissonnette, JP, Wilton, A, et al. Clinicopathologic analysis of 187 high-grade endometrial carcinomas of different histologic subtypes: similar outcomes belie distinctive biologic differences. Am J Surg Pathol 2007;31(7):979–87.
Zaino, RJ, Kurman, RJ, Diana, KL, Morrow, CP.The utility of the revised International Federation of Gynecology and Obstetrics histologic grading of endometrial adenocarcinoma using a defined nuclear grading system: A Gynecologic Oncology Group study. Cancer 1995;75:81–6.
Hampel, H, Frankel, W, Panescu, J, et al. Screening for Lynch syndrome (hereditary nonpolyposis colorectal cancer) among endometrial cancer patients. Cancer Res 2006;66(15):7810–17.
Ollikainen, M, Abdel-Rahman, WM, Moisio, AL, et al. Molecular analysis of familial endometrial carcinoma: a manifestation of hereditary nonpolyposis colorectal cancer or a separate syndrome?J Clin Oncol 2005;23(21):4609–16.
Leitao, MM, Kehoe, S, Barakat, RR, et al. Comparison of D&C and office endometrial biopsy accuracy in patients with FIGO grade 1 endometrial adenocarcinoma. Gynecol Oncol 2009;113(1):105–8.
Leitao, MM, Kehoe, S, Barakat, RR, et al. Endometrial sampling diagnosis of FIGO grade 1 endometrial adenocarcinoma with a background of complex atypical hyperplasia and final hysterectomy pathology. Am J Obstet Gynecol 2010;202(3):278.e1–6.
Mariani, A, Dowdy, SC, Cliby, WA, et al. Prospective assessment of lymphatic dissemination in endometrial cancer: a paradigm shift in surgical staging. Gynecol Oncol 2008;109(1):11–18.
Abu-Rustum, NR, Khoury-Collado, F, Pandit-Taskar, N, et al. Sentinel lymph node mapping for grade 1 endometrial cancer: is it the answer to the surgical staging dilemma?Gynecol Oncol 2009;113(2):163–9.
Abu-Rustum, NR, Zhou, Q, Gomez, JD, et al. A nomogram for predicting overall survival of women with endometrial cancer following primary therapy: toward improving individualized cancer care. Gynecol Oncol 2010;116(3):399–403.
Wheeler, DT, Bristow, RE, Kurman, RJ.Histologic alterations in endometrial hyperplasia and well-differentiated carcinoma treated with progestins. Am J Surg Pathol 2007;31(7):988–98.
Pecorelli, S.Revised FIGO staging for carcinoma of the vulva, cervix, and endometrium. Int J Gynaecol Obstet 2009;105(2):103–4.
Ali, A, Black, D, Soslow, RA.Difficulties in assessing the depth of myometrial invasion in endometrial carcinoma. Int J Gynecol Pathol 2007;26(2):115–23.
Murray, SK, Young, RH, Scully, RE.Unusual epithelial and stromal changes in myoinvasive endometrioid adenocarcinoma: a study of their frequency, associated diagnostic problems, and prognostic significance. Int J Gynecol Pathol 2003;22(4):324–33.
Longacre, TA, Hendrickson, MR.Diffusely infiltrative endometrial adenocarcinoma – an adenoma malignum pattern of myoinvasion. Am J Surg Pathol 1999;23(1):69–78.
Logani, S, Herdman, AV, Little, JV, Moller, KA.Vascular “pseudo invasion” in laparoscopic hysterectomy specimens: a diagnostic pitfall. Am J Surg Pathol 2008;32(4):560–5.
Kitahara, S, Walsh, C, Frumovitz, M, Malpica, A, Silva, EG.Vascular pseudoinvasion in laparoscopic hysterectomy specimens for endometrial carcinoma: a grossing artifact?Am J Surg Pathol 2009;33(2):298–303.
Zaino, RJ.FIGO staging of endometrial adenocarcinoma: a critical review and proposal. Int J Gynecol Pathol 2009;28(1):1–9.
Orezzoli, JP, Sioletic, S, Olawaiye, A, Oliva, E, del Carmen, MG.Stage II endometrioid adenocarcinoma of the endometrium: clinical implications of cervical stromal invasion. Gynecol Oncol 2009;113(3):316–23.
McCluggage, WG, Hirschowitz, L, Wilson, GE, et al. Significant variation in the assessment of cervical involvement in endometrial carcinoma: an interobserver variation study. Am J Surg Pathol 2011;35(2):289–94.
Tambouret, R, Clement, PB, Young, RH.Endometrial endometrioid adenocarcinoma with a deceptive pattern of spread to the uterine cervix: a manifestation of stage IIb endometrial carcinoma liable to be misinterpreted as an independent carcinoma or a benign lesion. Am J Surg Pathol 2003;27(8):1080–8.
Walsh, C, Holschneider, C, Hoang, Y, et al. Coexisting ovarian malignancy in young women with endometrial cancer. Obstet Gynecol 2005;106(4):693–9.
Shamshirsaz, AA, Withiam-Leitch, M, Odunsi, K, et al. Young patients with endometrial carcinoma selected for conservative treatment: a need for vigilance for synchronous ovarian carcinomas, case report and literature review. Gynecol Oncol 2007;104(3):757–60.
McKenney, JK, Kong, CS, Longacre, TA.Endometrial adenocarcinoma associated with subtle lymph-vascular space invasion and lymph node metastasis: a histologic pattern mimicking intravascular and sinusoidal histiocytes. Int J Gynecol Pathol 2005;24(1):73–8.
Lax, SF, Kendall, B, Tashiro, H, Slebos, R J C, Ellenson, LH.The frequency of p53, K-ras mutations, and microsatellite instability differs in uterine endometrioid and serous carcinoma – evidence of distinct molecular genetic pathways. Cancer 2000;88(4):814–24.
Soslow, RA, Shen, PU, Chung, MH, Isacson, C.Distinctive p53 and mdm2 immunohistochemical expression profiles suggest different pathogenetic pathways in poorly differentiated endometrial carcinoma. Int J Gynecol Pathol 1998;17:129–34.
Reid-Nicholson, M, Iyengar, P, Hummer, AJ, Linkov, I, Asher, M, Soslow, RA.Immunophenotypic diversity of endometrial adenocarcinomas: implications for differential diagnosis. Mod Pathol 2006;19(8):1091–100.
Kurman, RJ, Norris, HJ.Evaluation of criteria for distinguishing atypical endometrial hyperplasia from well-differentiated carcinoma. Cancer 1982;49:2547–59.
Longacre, TA, Chung, MH, Jensen, DN, Hendrickson, MR.Proposed criteria for the diagnosis of well-differentiated endometrial carcinoma: a diagnostic test for myoinvasion. Am J Surg Pathol 1995;19:371–406.
Young, RH, Treger, T, Scully, RE.Atypical polypoid adenomyoma of the uterus. A report of 27 cases. Am J Clin Pathol 1986;86:139–45.
Longacre, TA, Chung, MH, Rouse, RV, Hendrickson, MR.Atypical polypoid adenomyofibromas (atypical polypoid adenomyomas) of the uterus – a clinicopathologic study of 55 cases. Am J Surg Pathol 1996;20:1–20.
Silva, EG, Young, RH.Endometrioid neoplasms with clear cells: a report of 21 cases in which the alteration is not of typical secretory type. Am J Surg Pathol 2007;31(8):1203–8.
Tafe, L, Garg, K, Tornos, C, Soslow, R.Undifferentiated carcinoma of the endometrium and ovary: a clinicopathologic correlation. Mod Pathol 2009;22(1):238A.
Altrabulsi, B, Malpica, A, Deavers, MT, et al. Undifferentiated carcinoma of the endometrium. Am J Surg Pathol 2005;29(10):1316–21.
Silva, EG, Deavers, MT, Bodurka, DC, Malpica, A.Association of low-grade endometrioid carcinoma of the uterus and ovary with undifferentiated carcinoma: a new type of dedifferentiated carcinoma?Int J Gynecol Pathol 2006;25(1):52–8.
Ferguson, SE, Tornos, C, Hummer, A, Barakat, RR, Soslow, RA.Prognostic features of surgical stage I uterine carcinosarcoma. Am J Surg Pathol 2007;31(11):1653–61.
Murray, SK, Clement, PB, Young, RH.Endometrioid carcinomas of the uterine corpus with sex cord-like formations, hyalinization, and other unusual morphologic features: a report of 31 cases of a neoplasm that may be confused with carcinosarcoma and other uterine neoplasms. Am J Surg Pathol 2005;29(2):157–66.
Ladanyi, M, Lui, MY, Antonescu, CR, et al. The der(17)t(X;17)(p11;q25) of human alveolar soft part sarcoma fuses the TFE3 transcription factor gene to ASPL, a novel gene at 17q25. Oncogene 2001;20(1):48–57.