Mullerian adenosarcoma

Definition

A mixed mesenchymal and epithelial tumour usually with benign endometrial epithelium and low-grade malignant stroma resembling endometrial stromal sarcoma, most commonly arising in the uterus, sometimes in the ovary.

Epidemiology

There is a reported association with Tamoxifen therapy.

Histopathology

There is usually a phyllodes-like architecture. Tumour without stromal overgrowth have a stromal component that resembles low-grade endometrial stromal sarcoma, either conventional or with fibroblastic differentiation. Stromal overgrowth gives rise to a component that resembles fibrosarcoma or low grade endometrial stromal sarcoma with fibromyxoid features or high grade endometrial stromal sarcoma, sometimes with rhabdomyoblastic differentiation.

Immunohistochemistry

The stromal component shows a similar immunophenotype to low grade endometrial stromal sarcoma.

Differential diagnosis

• Endometrial stromal sarcoma

• Adenofibroma: rare; there is no periglandular condensation of stroma

• Carcinosarcoma: both epithelial and stromal components show high-grade malignancy.

• Botryoid embryonal rhabdomyosarcoma: usually occurs in the vagina of young girls; the stroma shows a cambium layer of concentration adjacent to epithelium.

Prognosis

Myometrial invasion, and sarcomatous stromal overgrowth are associated with aggressive behaviour.

References

1 Soslow RA, Ali A,Oliva E. Mullerian adenosarcomas: an immunophenotypic analysis of 35 cases. Am J Surg Pathol 2008; 32:1013-21

This page last revised 13.7.2008

MUHT/PW Bishop