Adult testicular granulosa cell tumors are rare sex cord-stromal tumors of which only 28 have been previously reported. As compared with their ovarian counterparts, these tumors may follow a more aggressive course because the proportion of malignant cases is higher. To date, there are no clinical or pathologic features that definitively predict malignancy. We reviewed all prior case reports for features that may predict their malignant potential. Tumor size greater than 5.0 cm is the only feature statistically associated with malignancy. Mitotic count, tumor necrosis, patient age, and the presence of gynecomastia do not, at present, predict benign versus malignant behavior.