Mesenteric chloroma with t(16;16) followed by acute myelomonocytic leukemia with clonal evolution

Myeloid Sarcoma With CBFB-MYH11 Fusion (inv(16) or t(16;16)) Prevails in the Abdomen

OBJECTIVES

Myeloid sarcoma with CBFB-MYH11 fusion may be enriched in abdominal sites. The clinicopathologic features of 11 cases are reported.

METHODS

We collected clinical features, morphology, immunophenotype, and bone marrow (BM) involvement of myeloid sarcoma cases with CBFB-MYH11 fusion.

RESULTS

Eleven of 29 total myeloid sarcoma cases were CBFB-MYH11 positive and all 11 involved abdominal sites. The blastic infiltrate was associated with eosinophils in four of 11 cases and plasmacytoid dendritic cell (pDC) nodules in four of six cases. CD34, CD117, and myeloperoxidase were expressed in eight of nine, 10 of 10, and 10 of 10 cases, respectively. Ten of 10 cases showed no BM involvement.

CONCLUSIONS

Our current series, combined with a literature review, identifies a compelling series of 31 (94%) of 33 cases of myeloid sarcoma with CBFB-MYH11 fusion showing a marked predilection for abdominal sites. In addition, the lack of obvious associated eosinophils, presence of pDC nodules, and lack of concurrent BM involvement suggest that "myeloid sarcoma with CBFB-MYH11 fusion" may represent a unique phenomenon.

Altered NFE2 activity predisposes to leukemic transformation and myelosarcoma with AML-specific aberrations

In acute myeloid leukemia (AML), acquired genetic aberrations carry prognostic implications and guide therapeutic decisions. Clinical algorithms have been improved by the incorporation of novel aberrations. Here, we report the presence and functional characterization of mutations in the transcription factor NFE2 in patients with AML and in a patient with myelosarcoma. We previously described NFE2 mutations in patients with myeloproliferative neoplasms and demonstrated that expression of mutant NFE2 in mice causes a myeloproliferative phenotype. Now, we show that, during follow-up, 34% of these mice transform to leukemia presenting with or without concomitant myelosarcomas, or develop isolated myelosarcomas. These myelosarcomas and leukemias acquired AML-specific alterations, including the murine equivalent of trisomy 8, loss of the AML commonly deleted region on chromosome 5q, and mutations in the tumor suppressor Trp53 Our data show that mutations in NFE2 predispose to the acquisition of secondary changes promoting the development of myelosarcoma and/or AML.

Leukemia in gastrointestinal organs as cause of treatment failure: 378 cases analyzed

Leukemia growing as tumors in gastrointestinal organs is an under-investigated cause of treatment failure and death. These present with symptoms often mistaken for common toxicities but may grow large before symptoms. To synthesize experience available only in case reports, 378 were analyzed. Invasive and metastatic behavior typical of solid GI tumors was revealed even when marrow was uninvolved. Within 3 months of diagnosis, 33% had died, 47% within 1 year. Survivals of 4 to 18 years after involvement suggest cure is possible. Evidence is presented that combined local and systemic therapy has successfully treated GI leukemic tumors when identified early.

Isolated duodenal myeloid sarcoma associated with the CBFβ/MYH11 fusion gene followed by acute myeloid leukemia progression: A case report and literature review

Myeloid sarcoma (MS) is a rare disease that presents as an extramedullary tumorous mass of immature myeloid precursors. The majority of MS are identified in acute myeloid leukemia (AML) patients and rarely present as a primary isolated MS without AML. In addition, inversion of chromosome 16 [inv(16)] and the CBFβ/MYH11 fusion gene are rarely associated with MS. The current study reports a female patient with an isolated duodenal MS, who developed AML-M4 associated with the CBFβ/MYH11 fusion gene and 48,XX,inv(16),+13,+22. A review of previously reported cases of isolated MS with the CBFβ/MYH11 fusion gene was also performed. Isolated MS with the CBFβ/MYH11 fusion gene was often observed in abdominal lesions, with the intestinal tract being the predominantly involved site. In addition, patients with isolated MS with the CBFβ/MYH11 fusion exhibited a high risk of developing systemic AML. The diagnosis of isolated MS may be particularly challenging and, therefore, determining the optimal standard treatment for isolated MS is required.

Clinicopathological characteristics of extramedullary acute megakaryoblastic leukemia (AMKL): report of a case with initial mastoid presentation and review of literature to compare extramedullary AMKL and non-AMKL cases

Extramedullary acute megakaryoblastic leukemia (AMKL) is a rare neoplasm with a varied clinical presentation. AMKL with initial mastoid presentation has never been reported. The extreme rarity of mastoid AMKL, together with the tendency of extramedullary AMKL to mimic other small blue cell tumors, can create a diagnostic challenge. We report a case of AMKL that initially presented as a mastoid lesion and provide a comprehensive review and analysis that compares the characteristics of extramedullary AMKL and nonmegakaryoblastic acute myeloid leukemia (AML) in reported pediatric cases over the past 30 years. We found that patients with extramedullary AMKL were not only younger than patients without megakaryocytic differentiation but were also limited to those ≤ 2 years of age. In addition, girls predominated in both AMKL and AML MLL(+) groups compared with other types of AML (P  =  0.0366 and P  =  0.0082). Furthermore, we found that extramedullary AMKL was more likely to involve bone than AML MLL(+) (P < 0.0001) or other types of AML (P  =  0.0002). These findings suggest that extramedullary AMKL should be considered in the differential diagnosis of SBCT in children, especially in patients with mastoid or other bony lesions, those ≤ 2 years of age, and female patients.

Granulocytic sarcoma of abdomen in acute myeloid leukemia patient with inv(16) and t(6;17) abnormal chromosome: case report and review of literature

Granulocytic sarcoma (GS) is composed of immature granulocytic precursors and is usually found in acute myeloid leukemia (AML) patients with t(8;21). Inv(16) is rarely associated with GS comparing with t(8;21) leukemia. Here we describe an abdominal GS patient in AML-M2 with acquired translocation between chromosomes 6 and 17 and inv (16). We have also summarized 20 reported GS cases with inv(16) and found that chloroma was most often found in abdominal lesions. Intestine maybe a tissue specific target for the expression of inv(16) leukemia. Complete physical examination and molecular diagnosis are necessary for AML patients to benefit from the diagnosis and therapeutic strategy.