[citation needed] Using next generation DNA sequencing, 97% of adult granulosa cell tumours were found to contain an identical mutation in the FOXL2 gene [1].

In-frame duplications in the pleckstrin-homology domain of the protein were found in more than 60% of juvenile granulosa cell tumours occurring in girls under 15 years of age.

The mutated proteins carrying the duplications displayed a non-wild-type subcellular distribution, with a marked enrichment at the plasma membrane, leading to a strong activation of AKT1.

[8] Analysis by RNA-Seq pinpointed a series of differentially expressed genes that are involved in cytokine and hormone signaling and cell division-related processes.

Further analyses pointed to a possible dedifferentiation process, and suggested that most of the transcriptomic dysregulations might be mediated by a limited set of transcription factors perturbed by AKT1 activation.

On cut-section, histology reveals reticular, trabecular areas with interstitial haemorrhage and Call–Exner bodies-small cyst like spaces interspersed within a Graafian follicle.