Endometrioid Carcinomas of the Uterine Corpus With Sex Cord-like Formations, corded and hyalinised endometrioid carcinoma, CHEC

Definition

An unusual variant of uterine endometrioid adenocarcinoma showing combinations of cords of epithelioid cells, spindle cells and hyalinised stroma.

Epidemiology

CHEC is seen across a wide age range in adult women. The mean age of 52 years is somewhat lower than for typical endometrioid carcinoma (60 years) or malignant mixed Mullerian tumour.

Histopathology

Tumours show a component of typical or villoglandular endometrioid adenocarcinoma, admixed with the CHEC component in varying proportions. Any myoinvasive component is usually typical endometrioid carcinoma. There is commonly a background of endometrial hyperplasia.

The CHEC component is composed of epithelioid cells and spindle cells. These show less atypia than in the typical endometrial carcinoma component and only rare mitoses. The epithelioid cells are arranged in cords. There is frequently focal squamous differentiation, often keratinising. . The cellular component is usually embedded within a hyalinised collagenous matrix. The matrix often forms osteoid, the lacunae of which contain entrapped epithelioid cells. Alternatively, the matrix may form small spherules. A component of fusiform cells may resemble endometrial stromal sarcoma, sometimes with a chondroid matrix.

Immunohistochemistry

	endometrioid glandular component	corded and hyalinised component
AE1/AE3	15/161	13/161
Vimentin	14/161	14/161
ER	7/101	5/101
PR	6/101	5/101
p53	6/101
CD10	1/101	0/101
Desmin	0/101	0/101
SMA	0/101	0/101
Inhibin	0/101	0/101

Differential diagnosis

Malignant mixed Mullerian tumour: is also biphasic. The spindle cells show greater atypia, often with high grade heterologous elements. Over-expression of p53 is usual.
Typical endometrioid carcinoma . Squamous differentiation is less common. Lacks stromal hyalinisation with osteoid metaplasia.
Endometrioid carcinoma with sex cord-like pattern / Sertoliform endometrioid carcinoma. The characteristic pattern is of hollow tubules, rather than cords. Stromal hyalinisation and spindle cells are not a feature.
Low grade endometrial stromal sarcoma with sex-cord like patterns. This tumour may show cords but is characterised by spindle cells and a network of small arterioles. Endometrial glands and squamous elements are lacking. There is permeation of the myometrium and its lymphatics. Hyalinisation takes the form of small plaques of a starburst pattern. Cytokeratin is negative and CD10 positive. Desmin and SMA are positive where there is smooth muscle differentiation.
Uterine tumour resembling ovarian sex cord tumour (UTROSCT). Shows a variety of pattern, including tubules, hollow or solid and cluster of luteinised cells, but lacks a component of typical endometrioid carcinoma, lacks squamous differentiation. May express cytokeratins, vimentin, desmin and inhibin.
Mullerian adenosarcoma. Shows intraglandular polypoidal projections of the sarcomatous stroma and sub-epithelial stromal condensations. The epithelial component is not frankly malignant.
Clear cell variant of endometrioid carcinoma: shows various patterns, including tubulocystic, papillary and solid, but not cord-like.
Metastatic lobular carcinoma of breast.

References

1Murray 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; 29:157-166

This page last revised 5.2.2005.