Sclerosing stromal tumor of the ovary

Sclerosing stromal tumor (SST) of the ovary is a rare ovarian neoplasm. It is considered a subtype of ovarian sex cord / stromal tumor and is included in the fibroma-thecoma group of ovarian tumors ⁹.

Epidemiology

It occurs predominantly in young women and its incidence peaks around the 2^nd to 3^rd decades of life ^1,2.

Clinical presentation

Patients may have menstrual irregularity and/or pelvic pain ⁴. It is usually hormonally inactive, but it may occasionally have an oestrogenic effect (even more rarely an androgenic effect).

Pathology

It is histologically characterized by cellular heterogeneity, prominent vasculature, and a pseudolobular appearance composed of cellular and hypocellular areas. They generally tend to be unilateral ³.

Radiographic features 

Ultrasound 

Described sonographic features (whilst being nonspecific) include tumor with multilocular cystic components and irregularly thickened septa and tumor walls or a solid tumor including several small cystic components ⁵. 

Pelvic MRI

Described signal characteristics include ⁵:

• T2
  • signal intensities of the cystic components are high and those of the solid components were inhomogeneous, ranging from intermediate-high to high
  • MR may show pseudolobulation ^7,8 of the lesion which consists of low-intensity nodules set against high-intensity stroma on T2-weighted images ⁷
• T1 C+ (Gd): dynamic imaging may show marked early enhancement of the solid components ^5,7

Differential Diagnosis

• Krukenberg tumor: usually occur in the 6^th and 7^th decades of life and often bilateral
• other sex cord stromal tumors: like fibroma and thecoma
• non-neoplastic conditions: like massive ovarian edema 

See also

• ovarian tumors