Rapidly growing juvenile granulosa cell tumor of the ovary arising in adult: a case report and review of the literature

Background: Ovarian granulosa cell tumors (GCTs) are divided into adult GCT (AGCT) and juvenile GCT (JGCT). The AGCT is more common type, conversely, less than 5% of tumors are the JGCT and occur in mainly premenarchal girls and in women younger than 30 years. Although JGCT have different histologic features compared to AGCT, the two types have similar imaging features because they have similar gross appearance. Therefore, it is difficult to distinguish two types by radiologic findings. In addition, it has not been described about the growth rate of JGCTs in past literatures. The aims of this report were to describe a case of rapidly growing JGCT arising in adult with difficulty in diagnosing and to review the literatures.

Case presentation: A 38-year-old woman, presented with abdominal distension and frequent urination, was found to have a pelvic mass measuring approximately 12 cm on ultrasonography. On magnetic resonance imaging (MRI), right ovarian multiloculated cystic mass accompanied with hemorrhagic foci was demonstrated. Although the presumptive diagnosis of GCT was made based on MR findings, the intraoperative differential diagnoses included GCT, yolk sac tumor or malignant mucinous tumor due to cytologic atypia and lack of the typical findings for AGCT such as nuclear grooves and Call-Exner bodies. As a result, abdominal simple total hysterectomy, bilateral oophoro-salpingectomy, partial omentectomy and appendectomy were performed. Moreover, she had a history of laparoscopic uterine myomectomy about one year before, and during that surgery bilateral ovaries were found to be macrospically normal. Therefore, it was suspected the tumor became enlarged within the short period of time.

Conclusions: Even though it is difficult to distinguish two types of GCT by imaging findings, in some cases without typical findings for AGCT pathologically, MRI could provide useful information in accurately diagnosing JGCT. Moreover, in this case, the tumor growth rate seemed to be rapid regardless of its borderline malignant potential. It may be related with nuclear atypia and high mitotic rate of the tumor.