[956] SALL4 and PAX8 Expression in Carcinomas from Various Organs

Fan Lin, Jianhiu Shi, Myra Wilkerson, Haiyan Liu. Geisinger Medical Center, Danville, PA

Background: SALL4 and PAX8 are two recently described important immunomarkers when working on a tumor of unknown origin. SALL4 is a sensitive maker for most germ cell tumors and hepatoid gastric carcinomas. PAX8 is a sensitive marker for thyroid carcinomas, gynecological carcinomas, thymic tumors, and renal cell carcinomas. In this study, we tested additional cases of carcinomas to expand our previous study.
Design: Immunohistochemical evaluation of the expression of SALL4 (Biocare Medical, CM384C) and mouse monoclonal antibody to PAX8 (Cell Marque, MRQ-50) on 1,129 cases of carcinomas from various organs using tissue mircroarray sections was performed. The staining intensity was recorded as weak or strong, and the distribution was recorded as 1+ to 4+.
Results: The positive staining results (%) and the total number of cases for each entity (N) are summarized in Table 1. Twenty-two cases of intratubular germ cell neoplasia (ITGCN) were also positive for SALL4. The majority cases of SALL4-positive non-germ-cell tumors were strongly and diffusely positive (3+ or 4+). Both SALL4 and PAX8 were negative in lung ADC (N=50) and lung SCC (N=49).

Table 1. Summary of Immunostaining Results
Seminoma (N=30)100%0
Embryonal CA (N=24)100%0
Yolk Sac Tumor (N=12)100%0
Lung ADC (N=50)00
Lung SCC (N=49)00
Papillary thyroid CA (PTC, N=45)093%
Follicular thyroid CA (FTC, N=36)0100%
Medullary thyroid CA (MTC, N=10)00
Anaplastic thyroid CA (ATC, N=5)040%
Clear cell RCC (N=36)097%
Papillary RCC (N=25)0100%
Colonic ADC (N=68)1 (3%)3% (2/68)
Esophageal ADC (N=30)1 (3%)0
Gastric ADC (N=21)00
Pancreatic ADC (N=50)00
Urothelial CA (N=83)4 (5%)0
Prostatic ADC (N=100)00
Cholangiocarcinoma (N=11)00
Breast ductal CA (N=110)00
Breast lobular CA (N=31)00
Endometrial CA (N=131)2 (1.5%)130 (99%)
Endocervical ADC (N=42)4 (9.5%)22 (53%)
Ovarian serous CA (N=56)2 (3.6%)56 (100%)
Hepatocellular CA (N=18)00
Pancreatic endocrine neoplasm (PEN, N=32)015 (47%)
Adrenal cortical neoplasm (N=24)00
ADC - adenocarcinoma; CA - carcinoma; RCC - renal cell carcinoma

Conclusions: These data confirm that SALL4 is a sensitive and specific marker for the diagnosis of germ cell tumors and ITGCN; however, caution should be taken because several different types of carcinomas can be strongly and diffusely positive for SALL4. PAX8 can be rarely positive in colonic ADC in addition to RCC, PTC, PEN, and gynecological carcinomas.
Category: Genitourinary (including renal tumors)

Wednesday, March 6, 2013 1:00 PM

Poster Session VI # 175, Wednesday Afternoon


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