Research Article: An Asymptomatic, Ectopic Mass as a Presentation of Adrenocortical Carcinoma Due to a Novel Germline TP53 p.Phe338Leu Tetramerisation Domain Variant
Abstract:
Adrenocortical carcinoma (ACC) is a rare cancer in childhood. ACC is frequently associated with germline TP53 variants, with founder effects especially due to the p.Arg337His mutation. ACC leads to the secretion of adrenocortical hormones, resulting in endocrine syndromes, which is the usual trigger for establishing the diagnosis. We present a surprising ACC pathology in a non-secreting, ectopic retroperitoneal tumour in a 4-year-old boy, successfully controlled with chemotherapy and mitotane after microscopically incomplete tumour resection with spillage. Genomic analysis (gene panel sequencing and copy-number microarray) demonstrated a novel p.Phe338Leu tetramerisation domain (TD) TP53 variant in the proband and his cancer-free mother and a monoallelic deletion encompassing the TP53 locus in cancer tissue, consistent with cancer-predisposition syndrome. While the recurrent p.Arg337His variant translates into high ACC risk, residue 338 and, in general, TD domain variants drive heterogeneous clinical scenarios, despite generally being considered less disruptive than TP53 DNA-binding domain mutations.
Introduction:
Adrenocortical carcinoma (ACC) is a rare cancer in childhood, constituting approximately 0.2% of all paediatric malignancies, with an incidence of 1 new case per 5 million children annually. ACC is characterised by two incidence peaks in childhood, the first under 3 years of age and the second in adolescence [1,2,3,4,5,6]. ACC is very frequently associated with germline pathogenic variants in the TP53 tumour-suppressor gene consistent with Li–Fraumeni syndrome and thus might be much more prevalent in populations…
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