Uterine Serous Carcinoma (USC)

 

Epidemiology:

    • Older patients than endometrioid CA

 

Common sites:

    •  

 

Gross features:

    •  

 

Histologic features:

    • resembles ovarian serous carcinoma
    • coarse fibrovascular stalks
      • broad
      • often hyalinized
    • lining cells are layered, large, highly malignant-appearing
      • macronucleoli
      • multinucleated tumour giant cells
      • marked hyperchromasia
      • nucleomegaly
      • abnormal mitotic figures
    • detached tufts between papillae (useful)
    • abundant mitoses
    • psammoma bodies (30%)
      • note: psammoma bodies in post-menopausal women are usually not associated with malignancy
    • propensity for LVI and myometrial invasion
      • presence of LVI is a prognostic factor
    • in situ involvement can be seen in adjacent endometrium

 

Immunophenotype:

Marker:

Sensitivity:

Specificity:

 ER/PR (neg)

 

 

P53

> 80% (strong)

 

MIB-1

(diffuse > 75%, strong)

 

 

P16

> 90% (strong)

 

 

Molecular features:

    • aneuploid
    • c-myc amplification often
    • HER-2/neu overexpression

 

Other features:

    • curettage may only reveal a few tumour cells, because intraendometrial involvement may be small
    • propensity for early metastases and peritoneal involvement
    • not associated with hormone replacement therapy
    • not associated with endometrial hyperplasia
    • worse prognosis

 

References:

    •