Undifferentiated Carcinoma of the Endometrium

Abstract

Undifferentiated carcinoma arising in the endometrium is considered a rare neoplasm with only a few studies published thus far. This limited number of studies is most likely a reflection of the underrecognition of this tumor because of a lack of diagnostic criteria to separate it from endometrial endometrioid adenocarcinoma, FIGO grade 3. In this study, we present the clinicopathologic features of 16 cases of endometrial undifferentiated carcinoma. In addition, we review the clinicopathologic features of 33 cases of endometrial endometrioid adenocarcinoma, FIGO grade 3, and compare them with the undifferentiated cases. The age of the 16 patients with undifferentiated carcinoma of the endometrium ranged from 40 and 69 years (mean, 59 years). Stage was known in 13 patients. Six (46%) patients presented with early stage disease (4 stage I and 2 stage II). Seven (54%) patients presented with advanced stage disease (2 stage III and 5 stage IV). Staging information was not available for 3 patients. Undifferentiated carcinoma was characterized by a proliferation of medium-sized, monotonous, epithelial cells growing in solid sheets with no specific pattern. Glands were not identified. Keratin immunostaining was focally positive in 11 of 12 cases, and EMA was focally positive in all 12 cases. The age of the 33 patients with endometrial endometrioid carcinoma, FIGO grade 3, ranged from 40 to 90 years (mean, 68 years). Twenty-three (70%) patients presented with early stage disease (21 stage I and 2 stage II), and 10 (30%) patients presented with advanced stage disease (8 stage III and 2 stage IV). Focal glandular differentiation was seen in all cases. The solid component was different from the one seen in the undifferentiated carcinomas because well demarcated trabeculae, cords, or groups of cells were identified in all cases. The tumor cells in the solid areas resembled the cells in the glandular component of the tumor. Immunoperoxidase studies for keratin and EMA were positive in 23 of 23 cases. Twelve of the 16 (75%) patients with undifferentiated carcinoma died of disease; 10 (62.5%) of them within 5 years after diagnosis. In contrast, 13 of 33 (39.4%) patients with endometrial endometrioid carcinoma, FIGO grade 3, died of disease. Twelve (36.4%) died within 5 years after diagnosis. In summary, undifferentiated carcinoma of the endometrium appears to be more aggressive than endometrial endometrioid adenocarcinoma, FIGO grade 3. Its proper recognition is important for prognosis and potentially for therapy.

ZEB1 overexpression associated with E-cadherin and microRNA-200 downregulation is characteristic of undifferentiated endometrial carcinoma

“…1,2,4 In this study, we investigated the molecular changes associated with undifferentiated endometrial carcinoma development, as well as those involved in tumor dedifferentiation.…”

“…1 Altrabulsi et al 2 defined undifferentiated endometrial carcinoma as a 'tumor composed of medium or large size cells with a complete absence of glandular differentiation, and with absent or minimal (o10%) neuroendocrine differentiation.' Undifferentiated endometrial carcinoma represents about 9% of all endometrial carcinomas.…”

A practical approach to the diagnosis of mixed epithelial and mesenchymal tumours of the uterus

“…23 Another endometrial tumour that is commonly confused with carcinosarcoma is the combination of an undifferentiated endometrial carcinoma and a low-grade endometrioid adenocarcinoma (mixed endometrioid and undifferentiated carcinoma or dedifferentiated endometrioid adenocarcinoma). [24][25][26] Undifferentiated carcinoma is an uncommon, but not rare, neoplasm included in the WHO classification of endometrial carcinomas. 1,[24][25][26] It is defined as 'a tumour composed of medium or large cells with complete absence of squamous or glandular differentiation and with absent or minimal (o 10%) neuroendocrine differentiation'.…”

“…[24][25][26] Undifferentiated carcinoma is an uncommon, but not rare, neoplasm included in the WHO classification of endometrial carcinomas. 1,[24][25][26] It is defined as 'a tumour composed of medium or large cells with complete absence of squamous or glandular differentiation and with absent or minimal (o 10%) neuroendocrine differentiation'. It may occur in pure form or in combination with and probably as a result of dedifferentiation in a low-grade (grade 1 or 2) endometrioid adenocarcinoma.…”

Undifferentiated Endometrial Carcinoma: A Diagnosis Frequently Overlooked

“…1 The World Health Organization (WHO) classification in Tumours of the Breast and Female Genital Organs 2 mentions UEC with only few lines appended, defining it as carcinoma lacking any evidence of differentiation. Recently, a few studies [3][4][5] have been published in the literature, describing histologic findings of UEC. Its prevalence is believed to be higher than had been previously thought, as many cases of UEC were either reported as endometrioid adenocarcinoma FIGO (International Federation of Gynecology and Obstetrics) grade 3, [6][7][8] or as high-grade sarcomas and carcinosarcomas.…”