What causes Ovarian sex cord tumor with annular tubules ?
What causes an ovarian sex cord tumor with annular tubules? Approximately one third of ovarian sex cord tumors with annual tubules (SCTATs) develop because of an underlying genetic condition called Peutz Jeghers syndrome (PJS), which is caused by a mutation in the STK11 gene.  In these genetic cases, many small SCTATs develop in both ovaries and are almost always benign.  The remaining two thirds of ovarian SCTATs are not related to a genetic condition and develop as a single tumor in one ovary; up to 25% of SCTATs in this group may be malignant.  Ovarian SCTATs not related to PJS have no known cause and are believed to occur by chance.