In SLCTs, the most important prognostic factors in these tumors are their stage and degree of differentiation [13]. Although all well-differentiated SLCTs behave as benign, 11 % of tumors with intermediate differentiation, 59 % of tumors with poor differentiation are malignant [13–15]. Poorly differentiated SLCTs tend to contain areas of hemorrhage and necrosis more frequently, compared to well-differentiated tumor [16].

The recurrent sex cord-stromal tumors are usually peritoneal seeding as nodules or infiltrative masses on the peritoneal surface, most commonly in the pelvic cavity or around the liver or undersurface of diaphragm (Fig. 2). Occasionally, recurrent tumor may also be encountered in the retroperitoneum (Fig. 3). The tumors may show variable imaging appearances from thin-walled cystic masses to solid masses (Fig. 2) [17]. The cystic mass may be accompanied by a fluid-fluid level, reflecting intratumoral hemorrhage (Fig. 3). Although nodal involvement at the time of primary surgery is extremely low, nodal involvement at the time of recurrence has been documented in 5 % of cases [18]. However, different from nodal metastases in ovarian carcinomas, the number of nodal involvement is usually limited. In cases of recurrent GCTs, omental or mesenteric infiltration and a large amount of ascites is quite unusual, unlike more common ovarian carcinomas of epithelial type [17].