Serous carcinoma of the ovary

Serous carcinoma of the ovary, also ovarian serous carcinoma, is relatively common malignant ovarian tumour.

Serous carcinoma of the ovary
Diagnosis in short
Serous carcinoma. H&E stain.
LM DDx	serous carcinoma from other sites, clear cell carcinoma of the ovary, poorly differentiated endometrioid carcinoma of the ovary, ovarian serous borderline tumour for low-grade tumours
IHC	WT-1 +ve, CK7 +ve, ER +ve, HNF-1beta -ve
Molecular	+/-BRCA1 mutation, +/-BRCA2 mutation
Gross	solid and cystic, serous fluid
Site	ovary - see ovarian tumours
Signs	adnexal mass
Blood work	CA-125 elevated
Radiology	complex mass with solid and cystic area, often large
Prognosis	poor for high-grade
Treatment	surgery, chemotherapy

General

• Most common malignant ovarian tumour in the eldery.
• Poor prognosis.
• May be associated with a BRCA1 gene or BRCA2 gene mutation.
  • Approximately 20% of high-grade serous carcinoma are associated with BRCA1 or BRCA2.

Precursors lesions:

• Serous borderline tumours for low-grade serious carcinoma.
• Serous tubal intraepithelial carcinoma (STIC) for high-grade serous carcinoma.

Gross

• Ovarian mass.
  • Typically solid with multiple cystic areas.
  • Often >10 cm.

Note:

• Lesions <10 cm and unilocular are usually benign.

Microscopic

Features:

• Nuclear pleomorphism:
  • Variation in size - often marked.
  • Variation in staining.
  • Variation in shape.
• +/-Macronucleolus - key feature.
• Eccentric nucleus.
• Architecture:
  • Solid.
  • Papillary - classic.
  • Glandular - uncommon.
• +/-Psammoma bodies - uncommon.
• +/-Necrosis - often extensive.

DDx:

• Clear cell carcinoma of the ovary - less nuclear size variation.
• Endometrioid carcinoma of the ovary - usu. lower grade.
• Primary peritoneal serous carcinoma - bulk of tumour in peritoneum, small ovarian tumour.
• Other non-ovarian serous carcinomas - see serous carcinoma.
• Ovarian serous borderline tumour - mild to moderate nuclear atypia, no invasion, few mitoses.

Grading

Serous carcinoma is subdivided into:

Grade	Nuclear atypia (most important)	Mitotic rate
Low-grade (Type I)	mild/moderate atypia: round/oval nuclei, evenly distributed chromatin, +/-conspicuous nucleoli	<=12 mitoses/10 HPFs †
High-grade (Type II)	severe atypia: >=3:1 size variation, irregular chromatin, +/-macronucleoli	>12 mitoses/10 HPFs †

Notes:

• † Definition suffers from HPFitis.
  • In fairness, the paper notes that the Olympus BH2 microscope was used. The 40x objective on this microscope has a field diameter of 0.5 mm, according to a manual found online. Assuming this is so, the field area is 0.19635 mm². Thus, in standard units, the cut-point would be 6.1115 mitoses/1 mm² and the sample area 1.9635 mm².
• Tumours very rarely transform from low-grade to high-grade.

Images

• 

  Serous ca - high mag.

• 

  Serous ca - very high mag.

• 

  Serous ca - very high mag.

• 

  Serous carcinoma - cytology. (WC)

www:

• Serous carcinoma - grade 1, 2 and 3 (nih.gov).

IHC

• WT-1 +ve - key immunostain.
• CK7 +ve.
• CA-125 +ve.
• ER +ve.
• p53 +ve/-ve.
  • p16 -ve/+ve.

Others:

• HNF-1beta -ve.
  • Usually +ve in clear cell carcinoma of the ovary.
• PAX2 +ve.
  • Usually -ve in malignant mesothelioma.

Sign out

A. RIGHT OVARY, BIOPSY:
- SEROUS CARCINOMA, HIGH-GRADE.
- PSAMMOMATOUS CALCIFICATIONS.

B. OMENTUM, BIOPSY:
- SEROUS CARCINOMA, HIGH-GRADE.
- PSAMMOMATOUS CALCIFICATIONS.

COMMENT:
The morphology is compatible with a serous carcinoma (prominent 
nucleoli, large nuclear size variation, psammomatous calcifications).

The immunostaining is that of a serous carcinoma:
POSITIVE: CK7, ER, PR (focal), CA-125, WT-1.
NEGATIVE: CK20, p53.

The ovary has multiple small tumour nodules.  The status of the opposite 
ovary is unknown. The bulk of the tumour in the specimen provided is in 
the omentum.

Clinical and radiologic correlation is suggested for the determination of 
the primary site of this serous carcinoma.

See also

• Ovary.
• Ovarian tumours.