the duplications displayed a non-wild-type subcellular distribution, with a marked enrichment at the plasma membrane, leading to a strong activation of AKT1. 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. These results incriminate somatic mutations of AKT1 as probable driver events in the pathogenesis of juvenile granulosa cell tumours. Diagnosis Gross appearance Tumours vary in size, from tiny spots to large masses, with an average of 10 cm in diameter. Tumours are oval and soft in consistency. On cut-section, histology reveals reticular, trabecular areas with interstitial haemorrhage and Call–Exner bodies-small cyst like spaces interspersed within a Graafian follicle. Tumour marker Inhibin, a hormone, has been used as biomarker for granulosa cell tumours. In animals In the ovaries of aging squirrel monkeys (Saimiri sciureus), clusters of granulosa cells occur that resemble granulosa cell tumours in humans. These appear to be a normal change with age in this species. See also Inhibin, alpha References External links Gynaecological cancer Male genital neoplasia Andrology Rare cancers Pediatric cancers