Refractory hemophagocytic lymphohistiocytosis in an adult patient with occult ALK-Positive anaplastic large cell lymphoma and a heterozygous MEFV mutation

Germline mutations in cancer predisposition genes among pediatric patients with cancer and congenital anomalies

BACKGROUND

Childhood cancer has a poorly known etiology, and investigating the underlying genetic background may provide novel insights. A recognized association exists between non-chromosomal birth defects and childhood cancer susceptibility.

METHODS

We performed whole-exome sequencing and chromosomal microarray analysis in a cohort of childhood cancer (22 individuals, 50% with congenital anomalies) to unravel deleterious germline variants.

RESULTS

A diagnostic yield of 14% was found, encompassing heterozygous variants in bona fide dominant Cancer Predisposition Genes (CPGs). Considering candidate and recessive CPGs harboring monoallelic variants, which were also deemed to play a role in the phenotype, the yield escalated to 45%. Most of the deleterious variants were mapped in genes not conventionally linked to the patient's tumor type. Relevant findings were detected in 55% of the syndromic individuals, mostly variants potentially underlying both phenotypes.

CONCLUSION

We uncovered a remarkable prevalence of germline deleterious CPG variants, highlighting the significance of a comprehensive genetic analysis in pediatric cancer, especially when coupled with additional clinical signs. Moreover, our findings emphasized the potential for oligogenic inheritance, wherein multiple genes synergistically increase cancer risk. Lastly, our investigation unveiled potentially novel genotype-phenotype associations, such as SETD5 in neuroblastoma, KAT6A in gliomas, JAG1 in hepatoblastomas, and TNFRSF13B in Langerhans cell histiocytosis.

IMPACT

Novel gene-phenotype associations and candidate genes for pediatric cancer were unraveled, such as KAT6A in gliomas, SETD5 in neuroblastoma, JAG1 in hepatoblastomas, and TNFRSF13B in Langerhans cell histiocytosis. Our analysis revealed a high frequency of deleterious germline variants, particularly in cases accompanied by additional clinical signs, highlighting the importance of a comprehensive genetic evaluation in childhood cancer. Our findings also underscored the potential for oligogenic inheritance in pediatric cancer risk. Understanding the cancer etiology is crucial for genetic counseling, often influencing therapeutic decisions and offering valuable insights into molecular targets for the development of oncological therapies.

ALK-Positive Anaplastic Large Cell Lymphoma Associated With Hemophagocytic Lymphohistiocytosis

Hemophagocytic lymphohistiocytosis (HLH) has been rarely reported as a complication of anaplastic large cell lymphoma (ALCL), especially in the adult population. We herein present a case of a young woman who presented with multiorgan failure and disseminated intravascular hemolysis and was later found to have ALCL-associated HLH. We also review the current literature on ALCL-associated HLH in adult patients, with their respective treatments and outcomes. We discuss the challenges associated with the diagnosis of lymphoma in the setting of HLH and multiorgan failure. Further, given its high mortality rates, we highlight the importance of promptly identifying and treating the underlying etiology of HLH.