TP53 and PTEN mutations were shared in concurrent germ cell tumor and acute megakaryoblastic leukemia

Keiichi Akizuki,Kotaro Shide,Yasunori Kogure,Hiroaki Kataoka,Masaaki Sekine,Kazuya Shimoda,Yuichiro Sato,Keisuke Kataoka,Takuro Kameda,Yoko Kubuki,Yuki Tahira,Junji Koya,Hiroyuki Tanaka,Takumi Kiwaki,Ayako Kamiunten,Tomonori Hidaka

doi:10.1186/s12885-019-6497-0

Abstract

BackgroundThe occurrence of a mediastinal germ cell tumor (GCT) and hematological malignancy in the same patient is very rare. Due to its rarity, there have been only two reports of the concurrent cases undergoing detailed genetic analysis with whole-exome sequencing (WES), and the possible clonal relationship between the both tumors remained not fully elucidated.MethodsWe performed whole-exome sequencing analysis of mediastinal GCT and acute myeloid leukemia (AML) samples obtained from one young Japanese male adult patient with concurrent both tumors, and investigated the possible clonal relationship between them.ResultsSixteen somatic mutations were detected in the mediastinal GCT sample and 18 somatic mutations in the AML sample. Mutations in nine genes, including TP53 and PTEN both known as tumor suppressor genes, were shared in both tumors.ConclusionsAll in our case and in the previous two cases with concurrent mediastinal GCT and AML undergoing with whole-exome sequencing analysis, TP53 and PTEN mutations were commonly shared in both tumors. These data not only suggest that these tumors share a common founding clone, but also indicate that associated mediastinal GCT and AML harboring TP53 and PTEN mutations represent a unique biological entity.

Highlights

The occurrence of a mediastinal germ cell tumor (GCT) and hematological malignancy in the same patient is very rare
Hematological malignancies (HM) associated with Mediastinal germ cell tumor (mGCT) should be separated from therapy-related secondary acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS), which typically develop at least a year following exposure to cytotoxic drugs administered for GCT treatment
The frequent presence of isochromosome 12p in AML samples from these patients strongly suggested that the HMs and mGCTs might arise from common progenitor cells, because isochromosome 12p is the most common chromosomal abnormality in GCTs, but is exceptionally rare in AML without mGCT association [5,6,7,8]

Summary

Introduction

The occurrence of a mediastinal germ cell tumor (GCT) and hematological malignancy in the same patient is very rare. Since 1985, the unique and rare associations between hematological malignancies (HMs) and mGCTs were reported in approximately 60 cases [3, 4]. The frequent presence of isochromosome 12p in AML samples from these patients strongly suggested that the HMs and mGCTs might arise from common progenitor cells, because isochromosome 12p is the most common chromosomal abnormality in GCTs, but is exceptionally rare in AML without mGCT association [5,6,7,8]. One of them was Caucasian and the other was not referred for its ethnicity This discovery strengthened the concept of the common progenitor cells, and provided insights into the molecular aspects of this unique and rare association [9, 10]. We report a third case of the concurrent occurrence of mediastinal GCT and AMKL, in which we performed whole-exome sequencing (WES) analysis of both tumors and investigated the possible clonal relationship between them

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Discussion

Conclusion