[465] Mammary and Extramammary Paget Disease: Clinicopathologic Correlation and Immunohistochemical Analysis

Sapna M Amin, Fang Fan, Ossama Tawfik. University of Kansas Medical Center, Kansas City, KS

Background: While mammary Paget disease (MPD) is usually associated with an underlying breast carcinoma, the majority of extramammary Paget disease (EMPD) do not have an underlying malignancy. However, both diseases share similar tumor morphology and the same intraepidermal tumor growth pattern. We examined the clinicopathologic features of MPD and EMPD and compared the expression of androgen receptor (AR), estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (Her2), gross cystic disease fluid protein (GCDFP-15), E-cadherin, and Ki-67 between the two neoplasms.
Design: A retrospective review of all biopsy-proven cases of MPD and EMPD diagnosed at our institution between 2002 and 2010 was conducted. Immunohistochemical studies for AR, ER, PR, Her2, GCDFP-15, E-cadherin, Ki-67 were performed on tissue from the paraffin block. The clinical characteristics, histologic features, and biomarkers were compared between cases of MPD and EMPD.
Results: Nine MPD cases and 6 EMPD cases were identified. The extramammary tumor sites included penis, scrotum, groin, vulva and perianal area. The clinicopathologic data and immunohistochemical profile of these cases are shown in the following table.

 Mammary Paget Disease (N=9)Extramammary Paget Disease (N=6)
Mean Age (years)61 (range 40-78)69 (range 56-82)
SexAll femaleMale: 5; female: 1
Underlying carcinomaabsent: 2absent: 5
 in-situ carcinoma: 2present: 1
 invasive carcinoma: 5 
ARPositive: 5; negative: 4Positive: 4; negative: 2
ER+/PR+/Her2-10
ER+/PR+/Her2+00
ER-/PR-/Her2+61
ER-/PR-/Her2-15
GCDFP-15Positive: 2; negative: 7Positive: 2; negative: 4
E-cadherinAll positiveAll positive
Ki-67>10%: 3; ≤10%: 6>10%: 3; ≤10%: 3



Conclusions: MPD and EMPD (with and without underlying carcinoma) shared similar biomarker expressions for AR/ER/PR and comparable immunohistochemical profiles for GCDFP-15, E-cadherin and Ki-67. However, the majority of MPD cases demonstrated overexpression of Her2, while the majority of EMPD cases were triple negative. This finding may have therapeutic implications.
Category: Dermatopathology

Tuesday, March 20, 2012 9:30 AM

Poster Session III # 106, Tuesday Morning

 

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