We present an unusual case of a young woman with rare bilateral, very aggressive ovarian granulosa cell tumour (GCT), comprised of granulosa, sarcomatoid and fibrothecomatous fields with significantly different immunostaining of primary and metastatic tumours showing stronger WT1, Bcl2, fascin and EGFR expression in metastases. Despite radical surgery and chemotherapy the tumour recurred rapidly and the patient died 16 months later. Such results clearly demonstrate the usefulness of immunostaining for the above markers as prognostic/predictive factors and the need for careful assessment of the immunoprofile of both primary and metastatic tumours, which can be useful for therapy and follow-up planning in GCT cases.
Keywords: fibrothecomatous differentiation; immunoprofile; sarcomatoid differentiation.