Rare myeloid sarcoma with KMT2A (MLL)-ELL fusion presenting as a vaginal wall mass

Abstract

Backgroud Myeloid sarcoma (MS) is a rare neoplasm of immature myeloid precursors that form tumor mass outside the bone marrow. The diagnosis of de novo MS can be challenging, particularly in patients with no prior history of hematologic malignancies or when MS involves unusual anatomic sites. Case presentation The patient was a 53-year-old woman with a history of uterine fibroids and vaginal bleeding for many years who presented with a vaginal wall mass. The tumor had histologic and phenotypic features of histiocytic sarcoma, however, overlapping with a possible extramedullary MS. Using a comprehensive genomic profiling, we were able to identify recurrent chromosomal aberrations associated with MS including a rare KMT2A - ELL fusion, losses of chromosomes 1p, 9, 10, 15, 18, and gain of chromosome 1q and mutations in FLT3 and PTPN11 , and achived the final diagnosis of a de novo MS. The patient received standard treatment for acute myeloid leukemia regimen with stem cell transplantation and achieved complete remission. Conclusion Our case illustrates the clinical utility of comprehensive genomic profiling in assisting the diagnosis or differential diagnosis of challenging MS or histiocytic sarcoma cases, and in providing important information in tumor biology for appropriate clinical management.

Primary splenic histiocytic sarcoma associated with hemophagocytic lymphohistiocytosis: A case report and review of literature of next‐generation sequencing involving FLT3, NOTCH2, and KMT2A mutations

“…NGS demonstrated FLT3 mutation, but no medical literature was found that associates these two neoplasms. The findings in our case may suggest genomic links between MS and HS 11 …”

“…Bao et al highlight the importance of KMT2A mutations and rearrangements found in MS with HS‐like morphology, leading us to consider the relationship that these two neoplasms may have in addition to their common oncogenic pathway. We have so far found no literature describing the possibility of transdifferentiation from HS to MS 11 . We ruled out myeloid sarcoma among other entities due to our histological and immunohistochemical findings.…”

Primary Splenic Histiocytic Sarcoma Associated with Hemophagocytic Lymphohistiocytosis (Hemophagocytic Syndrome): A Case Report of Next-Generation Sequency Involving FLT3, NOTCH2, and KMT2A Mutations

“…NGS demonstrated FLT3 mutation, but no medical literature was found that associates these two neoplasms. The ndings in our case may suggest genomic links between MS and HS [11].…”

“…Mutation of this gene is found in 5%-10% of adult acute myeloid and lymphocytic leukemias; such cases are characterized by poor prognosis and refractory to treatment [14]. Bao et al [11] highlight the importance of KMT2A mutations and rearrangements found in MS with HS-like morphology, leading us to consider the relationship that these two neoplasms may have in addition to their common oncogenic pathway. We have so far found no literature describing the possibility of transdifferentiation from HS to MS [11].…”

“…Bao et al [11] highlight the importance of KMT2A mutations and rearrangements found in MS with HS-like morphology, leading us to consider the relationship that these two neoplasms may have in addition to their common oncogenic pathway. We have so far found no literature describing the possibility of transdifferentiation from HS to MS [11]. Other authors have reported molecular similarities with variants like those of our patient (NTRK1 in LCH), pointing to the possible importance of these mutations in histiocytosis and other hematological neoplasms [17].…”