This report highlights the importance of screening for DICER1 mutations in the presence of the early-onset features of this syndrome and extends the spectrum of DICER1-related tumors by showing the mutation in a case of ERMS of the uterine corpus.
The identified combination of genetic events indicates a relationship between the intracranial tumors analyzed and DICER1 predisposition syndrome-associated sarcomas such as embryonal rhabdomyosarcoma or the recently described group of anaplastic sarcomas of the kidney.
The metachronous occurrence of two unrelated tumor entities (eRMS and CBME) in a very young child within a short timeframe should have raised the suspicion of an underlying cancer susceptibility syndrome and should be prompt tested for DICER1.
A recurrent embryonal rhabdomyosarcoma (ERMS) of the broad ligament, first diagnosed at age 23 years, harboured biallelic pathogenic somatic DICER1 variants (1 truncating and 1 RNase IIIb missense).
DICER1 mutations also cause a range of other tumours, some of them in urogenital organs (cystic nephroma [CN], ovarian sex cord-stromal tumours, bladder and cervix embryonal rhabdomyosarcoma [ERMS]).
We focus on adult granulosa cell tumours (somatic monoallelic mutations in FOXL2), Sertoli-Leydig cell tumours, gynaecological embryonal rhabdomyosarcomas (germline and somatic mutations in DICER1), and small-cell carcinoma of the ovary, hypercalcaemic type (biallelic mutations in SMARCA4).