Objective Concurrent presence of endometrial hyperplasia or cancer in patients with granulosa cell tumors (GCTs) is common, with reported incidences of 25.6% to 65.5%. Consequently, bilateral salpingo-oophorectomy and hysterectomy is usually recommended in patients with a GCT, but this remains debatable. Our aim was to evaluate the need for hysterectomy in patients with GCTs by studying the incidence of pathologically confirmed endometrial abnormalities at the time of diagnosis of GCT and during follow-up.

Materials/Methods All cases of GCT between 1991 and 2012 were evaluated for endometrial pathology using the Dutch nationwide network and registry of histopathology and cytopathology (PALGA).

Results A total of 1031 cases of GCT were identified at a mean ± SD age of 55 ± 17 years. The incidence of GCTs in the period 1991–2012 was 0.61 per 100,000 women per year. Concurrent endometrial cancer at the time of diagnosis of GCT was found in 58 patients (5.9%) and endometrial hyperplasia in 251 patients (25.5%), including complex hyperplasia in 89 patients (9.1%) and simple hyperplasia in 162 patients (16.5%). Long-term follow-up of 490 patients (47.5%) without a hysterectomy showed that endometrial abnormalities were found in 10 patients (2.0%) of which 2 had endometrial cancer. Interestingly, 8 (80%) of the 10 patients with endometrial abnormalities had recurrent GCT at the time of diagnosis of endometrial hyperplasia or cancer.

Conclusions Our data suggest that after surgical removal of GCT, development of an endometrial abnormality, especially cancer, is very rare. Therefore, hysterectomy is not recommended in patients with a GCT without endometrial abnormalities at the time of diagnosis.