Synchronous T-lymphoblastic lymphoma and neuroblastoma in a 3-yr-old with novel germline SMARCA4 and EZH2 variants

Cold Spring Harb Mol Case Stud. 2024 Jan 10;9(4):a006286. doi: 10.1101/mcs.a006286. Print 2023 Dec.

Abstract

T-lymphoblastic lymphoma (T-LLy) is the most common lymphoblastic lymphoma in children and often presents with a mediastinal mass. Lymphomatous suprarenal masses are possible but rare. Here, we discuss the case of a previously healthy 3-yr-old male who presented with mediastinal T-LLy with bilateral suprarenal masses. Following initial treatment, surgical biopsy of persisting adrenal masses revealed bilateral neuroblastoma (NBL). A clinical genetics panel for germline cancer predisposition did not identify any pathogenic variants. Combination large panel (864 genes) profiling analysis in the context of a precision oncology study revealed two novel likely pathogenic heterozygous variants: SMARCA4 c.1420-1G > T p.? and EZH2 c.1943G > C p.(Ile631Phefs*44). Somatic analysis revealed potential second hits/somatic variants in EZH2 (in the T-LLy) and a segmental loss in Chromosome 19p encompassing SMARCA4 (in the NBL). Synchronous cancers, especially at a young age, warrant genetic evaluation for cancer predisposition; enrollment in a precision oncology program assessing germline and tumor DNA can fulfill that purpose, particularly when standard first-line genetic testing is negative and in the setting of tumors that are not classic for common cancer predisposition syndromes.

Keywords: T-cell lymphoma/leukemia; neuroblastoma.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Child
  • DNA Helicases / genetics
  • Enhancer of Zeste Homolog 2 Protein / genetics
  • Genetic Predisposition to Disease
  • Genetic Testing
  • Humans
  • Male
  • Neuroblastoma* / genetics
  • Nuclear Proteins / genetics
  • Precision Medicine
  • Precursor Cell Lymphoblastic Leukemia-Lymphoma*
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma*
  • Transcription Factors / genetics

Substances

  • SMARCA4 protein, human
  • DNA Helicases
  • Nuclear Proteins
  • Transcription Factors
  • EZH2 protein, human
  • Enhancer of Zeste Homolog 2 Protein