Germline ATM mutation and somatic PIK3CA and BCOR mutations found in an infant with aggressive orbital embryonal rhabdomyosarcoma

Pimkwan Jaru-Ampornpan; Chottiwat Tansirisithikul; Manachaya Prukajorn; Somponnat Sampattavanich; Manop Pithukpakorn

doi:10.1016/j.ajoc.2021.101189

Germline ATM mutation and somatic PIK3CA and BCOR mutations found in an infant with aggressive orbital embryonal rhabdomyosarcoma

Am J Ophthalmol Case Rep. 2021 Aug 4:23:101189. doi: 10.1016/j.ajoc.2021.101189. eCollection 2021 Sep.

Authors

Pimkwan Jaru-Ampornpan¹, Chottiwat Tansirisithikul², Manachaya Prukajorn¹, Somponnat Sampattavanich³, Manop Pithukpakorn⁴

Affiliations

¹ Department of Ophthalmology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
² Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
³ Department of Pharmacology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
⁴ Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.

Abstract

Purpose: To report a case of aggressive infantile orbital embryonal rhabdomyosarcoma harboring germline ATM mutation and 2 somatic mutations as revealed by next-generation sequencing and the potential application for personalized therapy.

Observations: A 7-month-old male developed a rapidly progressive left proptosis over 6 weeks due to a large medial orbital mass. Biopsy revealed embryonal rhabdomyosarcoma. After the first cycle of chemotherapy, re-imaging showed interval tumor enlargement with intracranial extension. Craniotomy, combined with orbital exenteration, was performed. Tumor specimens and blood samples were sent for 596 gene DNA sequencing panels with RNA-sequencing focused on actionable mutations as well as gene fusion detection. Sequencing revealed 3 clinically relevant mutations: a germline ATM loss-of-function (LOF) mutation, a somatic PIK3CA gain-of-function mutation, and a somatic BCOR LOF mutation. No chromosomal translocation was detected. Workup for metastasis was positive for bone marrow involvement. Despite standard high-dose adjuvant chemotherapy in combination with radiation therapy, the patient died 10 months later with metastatic diseases.

Conclusions and importance: This case highlights an aggressive form of embryonal rhabdomyosarcoma in an infantile orbit. The presence of germline mutation may explain the increased chemo-resistance and adverse prognosis, and may be used as the target for genomic-directed therapy.

Keywords: ATM mutation; Embryonal; Infantile; Orbit; Rhabdomyosarcoma.

Publication types

Case Reports