Recurrent ETNK1 mutations in atypical chronic myeloid leukemia.

Despite the recent identification of recurrent SETBP1 mutations in atypical chronic myeloid leukemia (aCML), a complete description of the somatic lesions responsible for the onset of this disorder is still lacking. To find additional somatic abnormalities in aCML, we performed whole-exome sequencing on 15 aCML cases. In 2 cases (13.3%), we identified somatic missense mutations in the ETNK1 gene. Targeted resequencing on 515 hematological clonal disorders revealed the presence of ETNK1 variants in 6 (8.8%) of 68 aCML and 2 (2.6%) of 77 chronic myelomonocytic leukemia samples. These mutations clustered in a small region of the kinase domain, encoding for H243Y and N244S (1/8 H243Y; 7/8 N244S). They were all heterozygous and present in the dominant clone. The intracellular phosphoethanolamine/phosphocholine ratio was, on average, 5.2-fold lower in ETNK1-mutated samples (P < .05). Similar results were obtained using myeloid TF1 cells transduced with ETNK1 wild type, ETNK1-N244S, and ETNK1-H243Y, where the intracellular phosphoethanolamine/phosphocholine ratio was significantly lower in ETNK1-N244S (0.76 ± 0.07) and ETNK1-H243Y (0.37 ± 0.02) than in ETNK1-WT (1.37 ± 0.32; P = .01 and P = .0008, respectively), suggesting that ETNK1 mutations may inhibit the catalytic activity of the enzyme. In summary, our study shows for the first time the evidence of recurrent somatic ETNK1 mutations in the context of myeloproliferative/myelodysplastic disorders.

A case report of a fulminant Aeromonas hydrophila soft tissue infection in a patient with acute lymphoblastic leukemia harboring a rare translocation.

INTRODUCTION: Aeromonads are gram-negative opportunistic bacteria, mainly found in aquatic environments. Hematologic patients are particularly at risk of Aeromonas soft tissue infections and septicemia, especially during chemotherapy-induced neutropenia. CASE DESCRIPTION: A 46-year-old man was diagnosed with acute lymphoblastic leukemia characterized by the rare t(12;17)(p13;q21)/TAF15-ZNF384 aberration. On day 22 of chemotherapy, he developed febrile neutropenia followed by necrotizing fasciitis in his upper right extremity. Despite appropriate antibiotic therapy and prompt surgical intervention, he died within 36 h after the appearance of a fever. A multi-sensitive Aeromonas hydrophila was isolated from all cultural sites. DISCUSSION AND CONCLUSIONS: In a previous paper we characterized the patient's aberration with cytogenetic and FISH analysis. Here, we provide details regarding the patient's rapidly progressing infection and underline the importance of maintaining high clinical suspicion of Aeromonas infections in acute leukemia. Given the unusually rapid progression of an infection caused by a rare non-resistant pathogen, and after considering data on the implication of metalloproteinase function in immune system regulation, a correlation between risk of severe infection and TAF15-ZNF384 aberrated acute lymphoblastic leukemia cannot be ruled out.

An Adult Patient with Early Pre-B Acute Lymphoblastic Leukemia with t(12;17)(p13;q21)/ZNF384-TAF15.

This is a case report of a 46-year-old man diagnosed with early pre-B acute lymphoblastic leukemia (ALL), bearing the translocation t(12;17)(p13;q21) as the sole chromosomal abnormality. This is a rare chromosomal abnormality that has been reported in approximately 25 cases worldwide. FISH analysis revealed a rearrangement of ZNF384 (12p13) and TAF15 (17q12) genes, which is usually associated with a pre-B ALL phenotype with co-expression of the myeloid markers CD13 and/or CD33. ZNF384 encodes a zinc finger protein, which acts as a transcription factor, regulating the expression of several matrix metalloproteinases and TAF15 belongs to the FET (FUS, EWS, and TAF15) family, consisting of RNA and DNA-binding proteins. Unlike most of the cases where CD10 expression was absent or weak, in our case CD10 was highly expressed. The prognostic significance of ZNF384/TAF15 fusion is not very clear since several reports support a generally good prognosis, while others support a poor clinical outcome. Our patient was treated with the German multicenter ALL (GMALL) protocol for B-ALL, but experienced a fulminant gram-negative sepsis and eventually died during induction therapy.

A case report of a very late response to 5-azacytidine in a patient with lower risk myelodysplastic syndrome: Time to update treatment guidelines for lower risk patients.

RATIONALE: The hypomethylating agent 5-azacytidine has been approved in Europe for patients with intermediate 2 and high (i.e., higher) risk myelodysplastic syndrome according to the International Prognostic Scoring System (IPSS). A total of 91% of all first responses in higher risk patients occur within 6 cycles of treatment; however, data regarding the time to first response in clinical trials with lower risk patients are not available. PATIENT CONCERNS: Our case describes the late response of a lower risk (intermediate 1 according to the IPSS and intermediate according to the IPSS-R) patient to 5-azacytidine treatment.Diagnosis and interventions: Once diagnosed, the patient started supportive treatment due to persistent pancytopenia and recurrent infections. The use of a hypomethylating agent was decided because the patient was transfusion dependent, and suffering from recurrent severe febrile infections due to neutropenia. Other possible causes of fever except infections in the context of his neutropenia were excluded. OUTCOMES: After the 12th cycle of 5-azacytidine the patient showed a hematologic response, with transfusion independency and with no recurrent febrile episodes. LESSONS: This case report probably indicates that a subset of patients who belong to the lower risk category according to the previous prognostic systems and to the intermediate one according to the IPSS-R, may benefit from prolonged treatment with the drug. The indication of 5-azacytidine in Europe for patients with higher risk myelodysplastic syndrome (MDS) (according to the IPSS) could possibly include a wider range of patients if updated according to the IPSS-R.

Isolated skeletal muscle recurrence of an originally nodal diffuse large B cell lymphoma: A case report and review of the literature.

RATIONALE: Diffuse large B cell lymphoma (DLBCL) is a malignancy of the B cells with extranodal primary involvement being estimated at 30% to 40% of cases. Primary skeletal muscle presentation of DLBCL is extremely rare, with an estimated incidence of about 0.5% of extranodal lymphomas, presenting mostly in the lower extremities. The possible mechanisms of muscle involvement of DLBCL include primary extranodal disease, extension from adjacent organs (such as lymph nodes) or disseminated disease. PATIENT CONCERNS: We report a case of a 70-year-old woman with an advanced initially nodal DLBCL, treated with R-CHOP, that presented with an enlargement of her left thigh and restricted mobility 3 months after completion of chemotherapy. Imaging studies were performed, which showed possible infiltration of the muscles of the left thigh, without any nodal disease present. DIAGNOSES: Muscle biopsy documented the recurrence of the lymphoma at the left thigh. INTERVENTIONS: The patient started second-line treatment with gemcitabine and vinorelbine. OUTCOMES: A partial response was achieved after the first cycle. LESSONS: The remarkable element lies in the reappearance of the lymphoma at the left thigh muscles, with no radiographic or clinical evidence of involvement of lymph nodes, despite the extensive lymph node disease at initial presentation. The further management of such recurrences remains to be clarified, as the odd biological behavior of the malignant cells dictates a special handling of the disease.

5-Azacytidine in the Treatment of Intermediate-2 and High-risk Myelodysplastic Syndromes and Acute Myeloid Leukemia. A Five-year Experience with 44 Consecutive Patients.

BACKGROUND/AIM: The hypomethylating agent 5-azacytidine has been the standard-of-care for patients with higher-risk myelodysplastic syndrome (MDS) during the past few years. Its efficacy has been proven in large clinical trials, and its safety has been shown to be superior to that of conventional treatments. PATIENTS AND METHODS: We conducted a retrospective study on the efficacy and safety of 5-azacytidine in 44 consecutive patients with MDS and acute myeloid leukemia treated with 5-azacytidine during a 63-month period. We recorded the clinical and laboratory characteristics of the patients and we analyzed the response to treatment, overall survival and adverse events during treatment. RESULTS: The median overall survival was 13 months, while serious adverse events consisted mostly of neutropenic infections. CONCLUSION: We reached two possibly valuable conclusions: Younger patients (<73 years), as well as patients receiving treatment at longer than 28-day intervals had a significantly higher overall survival.

An adult patient with systemic mastocytosis and B-acute lymphoblastic leukemia.

Mastocytosis is a myeloproliferative neoplasm characterized by clonal expansion of abnormal mast cells, ranging from the cutaneous forms of the disease to mast cell leukemia. In a significant proportion of patients, systemic mastocytosis (SM) coexists with another hematologic malignancy, termed systemic mastocytosis with an associated hematologic nonmast cell lineage disorder (SM-AHNMD). Despite the pronounced predominance of concomitant myeloid neoplasms, the much more unusual coexistence of lymphoproliferative diseases has also been reported. Imatinib mesylate (IM) has a role in the treatment of SM in the absence of the KITD816V mutation. In the setting of SM-AHNMD, eradicating the nonmast cell malignant clone greatly affects prognosis. We report a case of an adult patient with SM associated with B-lineage acute lymphoblastic leukemia (B-ALL). Three cases of concurrent adult ALL and mastocytosis have been reported in the literature, one concerning SM and two concerning cutaneous mastocytosis (CM), as well as six cases of concomitant CM and ALL in children.

Evidence for regulation of oxidative stress by latent membrane protein 1 oncoprotein in patients with low-grade leukemic B cell lymphoma with latent Epstein-Barr virus infection.

The role of latent Epstein-Barr virus (EBV) infection in the pathogenesis of low-grade B cell non-Hodgkin lymphoma (B-NHL) has not been studied. We therefore investigated the incidence of latent EBV infection in a group of patients with leukemic low-grade B-NHL, as well as the incidence of viral latent membrane protein 1 (LMP1) oncoprotein expression in the same patient group. Furthermore, in an attempt to elucidate the role of this viral oncoprotein in non-EBV-related lymphomas, we correlated the expression of LMP1 with the level of oxidative stress, a parameter related to apoptosis. In the present study we detected lower levels of oxidative stress in the sera of LMP1-positive patients. This possibly implies an anti-apoptotic role of this viral oncoprotein in low-grade B cell lymphomas. However, LMP1 expression status did not affect expression of the major anti-apoptotic gene BCL-2.

Cessation of tyrosine kinase inhibitors in patients with chronic-phase chronic myelogenous leukemia following durable complete molecular response: a single center facing the dilemma.

Tyrosine kinase inhibitors (TKIs), namely imatinib mesylate (IM) and recently approved second-generation TKIs dasatinib and nilotinib, are currently considered the treatment of choice for newly-diagnosed chronic phase chronic myelogenous leukemia (CP-CML). Although treatment with TKIs has not yet been proven curative, it certainly accomplishes a sustained control of the disease in the vast majority of patients. More than a decade after the successful launching of IM in first-line treatment of CP-CML and the subsequent introduction of second-generation TKIs in this setting, the question of the possibility of TKI cessation in a specific subset of patients has emerged. Side-effects of TKIs, along with some patients' wish to abandon the drugs and the rising financial burden upon healthcare systems, have led to the dilemma whether IM can be safely withdrawn after achieving deep molecular remissions and which patients are suitable for this discontinuation. We examined the data of our patients with CML in search of potential canditates for cessation of TKI therapy and identified their characteristics. We also performed a thorough review of the relevant literature. Eight out of fifty patients were discriminated on grounds of sustained complete molecular response (CMR) exceeding 12 months, most of them with a low or intermediate Sokal score at diagnosis. The median interval from IM initiation to CMR was almost 2 years and the median duration of detected CMR reached 6.5 years. Based on the promising results of prospective clinical trials reporting successful cessation of treatment with TKIs on selected subgroups of patients, we decided to proceed to interruption of therapy in the specific subset of our patients and closely monitor their response.