Comparative Utility of Novel Nuclear Markers Steroidogenic Factor (SF-1) and Forkhead Box L2 (FOXL2) in the Diagnosis of Sex Cord Stromal Tumors (SCST) of the Testis
Manju Aron, Allen M Gown, Bonnie L Balzer, Mitual Amin, Steven Shen, Donna E Hansel, Pheroz Tamboli, Gladell Paner, Daniel J Luthringer, Sambit K Mohanty, Loren P Herrera, Mahul B Amin. Cedars-Sinai Medical Center, Los Angeles; Phenopath Laboratories, Seattle; William Beaumont Hospital, Detroit; The Methodist Hospital, Houston; Cleveland Clinic, Cleveland; M.D. Anderson Cancer Center, Houston; University of Chicago, Chicago
Background: SCSTs of the testis may demonstrate a range of cytoarchitectural patterns that can overlap with other tumors including germ cell tumors, metastatic tumors and paratesticular neoplasms. Immunohistochemistry plays an important part in the diagnosis of SCST of the testis, and although several markers have been identified, many available markers have overlap in staining reaction with differential diagnostic considerations. SF-1 (adrenal 4-binding protein; Ad4BP) is a nuclear transcription factor involved in gonadal and adrenal development. FOXL2 is a transcription factor required for ovarian differentiation in mammals. Both SF-1 and FOXL2 have been recently shown to be of value in ovarian tumors, however the expression of these markers and their potential utility in SCST of the testis is largely unknown.
Design: A total of 24 cases of SCST of the testes comprising of Leydig cell tumor (n=9), Sertoli cell tumor (n=3), large cell calcifying Sertoli cell tumor (LCCSCT) (n=3), unclassified and mixed SCST (n=6), and 1 case each of testicular tumor of androgenital syndrome (TTAG), signet ring stromal tumor and granulosa cell tumor were included in the study. All the cases were stained by SF-1 and FOXL2. The extent and intensity of nuclear staining was graded both qualitatively and semiquantitatively.
Results: The results of the study are outlined in the table.
|Diagnosis||SF-1 percentage positivity||FOXL2 percentage positivity|
|Leydig cell tumor||78||11|
|Sertoli cell tumor||33||67|
|Signet ring stromal tumor||100||100|
|Granulosa cell tumor||0||100|