SATB2 Cytoplasmic Expression is Characteristic of a Subset of Ovarian Stromal Cells and Sex Cord Stromal Tumors.

Special AT-rich sequence-binding protein 2 (SATB2) is a nuclear transcription factor that shows consistent nuclear staining in colorectal adenocarcinoma and osteosarcoma. Following the observation of cytoplasmic staining with this marker in luteinized ovarian stromal cells, we studied the expression of SATB2 in ovarian stromal cells, various types of follicular cysts, and sex cord-stromal tumors. Eighty-five cases were stained for SATB2. Ovarian hilar Leydig cells (n = 12), luteinized stromal cells (n = 10), corpora lutea (n = 4), luteinized follicular cysts (n = 4), and stromal hyperthecosis (n = 6) exhibited consistent, usually diffuse, granular cytoplasmic staining. In addition, Leydig cell tumors (n = 1) and steroid cell tumors (n = 4) showed diffuse cytoplasmic staining. SATB2 also exhibited cytoplasmic staining in most Sertoli-Leydig cell tumors (n = 16) and gynandroblastomas (n = 3) confined to the Leydig cell component. Adult granulosa cell tumors (n = 14), juvenile granulosa cell tumors (n = 3), sex cord tumors with annular tubules (n = 3), cellular fibromas (n = 3), sclerosing stromal tumors (n = 1), and thecomas (n = 1) were negative apart from cytoplasmic staining in associated luteinized stromal cells. SATB2 cytoplasmic staining has not been previously described in these lesions but is characteristic of a variety of ovarian stromal cells and sex cord-stromal tumors, in particular, those exhibiting luteinization or a Leydig or steroid cell component. SATB2 staining may be of value in identifying luteinized or Leydig cells when these are morphologically inconspicuous.