[1190] Mammaglobin Expression in Primary Ovarian Carcinoma and Its Utility in the Differential Diagnosis of Metastatic Mammary Carcinoma to Ovary

Y Sun, P Newcomb, D Mandich, R Cartun, S Mandavilli. Hartford Hospital, Hartford, CT

Background: Metastatic mammary carcinoma to ovary (MMCA) can mimic primary ovarian carcinoma and pose a diagnostic dilemma. Mammaglobin (MG) has been suggested as a breast-specific marker, but there is limited literature evaluating MG expression in primary ovarian tumors. We wanted to evaluate the utility of MG and a panel of other IHC markers including breast-associated markers (GCDFP-15 and ER) along with markers seen in ovarian carcinomas (WT1 and CA125).
Design: 19 cases of primary ovarian tumors including 11 cases of endometrioid carcinoma (ECA), 5 papillary serous carcinoma (PSCA), 4 clear cell carcinoma (CCCA), 2 cases of undifferentiated carcinoma (UDCA) and 5 cases of MMCA including 3 cases of invasive ductal carcinoma and 2 cases of invasive lobular carcinoma were retrieved from the tertiary hospital pathology files. MG, GCDFP-15, ER, WT1, and CA125 immunostain were performed in all cases.
Results: MG was positive in 4 cases of MMCA (80%), but was also positive in 50% of ovarian ECA. GCDFP-15 was expressed in 3 cases of MCA (60%) and none of the primary ovarian tumors. ER was present in both MCA and primary ovarian tumors except CCCA. CA125 was seen in the majority of MMCA and one case of MMCA was WT-1 positive. The IHC results are summarized below:

IHC profile in MCCA and primary ovarian carcinoma

Diagnosis/case #	MG	GCDFP15	CA125	ER	WT-1
MCCA (5)	4 (80%)	3 (60%)	3 (60%)	5 (100%)	1 (20%)
ECA (8)	4 (50%)	0	7 (86%)	8 (100%)	3 (38%)
PSCA (5)	0	0	5 (100%)	5 (100%)	5 (100%)
CCCA (4)	0	0	3 (75%)	0	0
UDCA (2)	1 (50%)	0	1 (50%)	1 (50%)	0

Conclusions: MG was expressed in the majority of MMCA, but was also expressed in a significant proportion of ovarian ECA. GCDFP-15 was highly breast-specific and was not expressed in primary ovarian carcinomas. WT1 was seen in all ovarian serous carcinomas and can occasionally be expressed in MMCA. ER was not useful in this differential diagnosis. These results favor the use of a panel of IHC stains with careful evaluation of other clinical findings in distinguishing primary ovarian carcinoma from MMCA.
Category: Gynecologic & Obstetrics

Wednesday, March 24, 2010 1:00 PM

Poster Session VI # 179, Wednesday Afternoon