Candida parapsilosis bone marrow infection in an immunocompetent patient.

Background: We discuss a case of an immunocompetent patient who presented with fever and tachypnoea, found to have Candida parapsilosis bone marrow infection, cultured on bone marrow aspirate sample. Candida parapsilosis is an opportunistic yeast pathogen that typically affects immunocompromised individuals, or occurs in patients with apparent introduced source; neither of these factors were present for this case. Bone marrow aspirates and trephines are not regular investigations for fever; however they can be useful diagnostic aids as evidenced in this case. Case report: An 83-year-old woman presenting with fevers and tachypnoea was being treated for a systemic bacterial infection, however was unresponsive to empirical antibiotic therapy. To exclude an occult malignancy, an 18-fluorodeoxyglucose positron emission tomography scan was conducted. Significant bone marrow uptake was noted, prompting a bone marrow aspirate and trephine to investigate for a hematological malignancy. While the trephine biopsy was benign, a culture of the aspirate grew Candida parapsilosis. Intravenous antifungal therapy was initiated; however, the patient did not improve despite targeted therapy likely due to delays in diagnosis, and was palliated. Conclusion: Our case seeks to demonstrate a novel case whereby a bone marrow aspirate culture provided a conclusive diagnosis of invasive Candida parapsilosis bone marrow infection, and guided treatment in an immunocompetent patient. It is important for clinicians to consider invasive fungal infections in febrile patients regardless of immune status. Additionally, when performing a bone marrow aspirate and trephine on a febrile patient, we recommend including aspirate fungal cultures to investigate for an invasive fungal infection.

SOHO State of the Art Updates and Next Questions: Pre-emptive Therapy at Molecular Measurable Residual Disease Failure in Acute Myeloid Leukemia.

Molecular measurable residual disease (MRD, eg, by real-time quantitative polymerase chain reaction, RT-qPCR), is an integral part of response assessment in acute myeloid leukemia (AML) with established prognostic and evolving therapeutic significance. MRD failure can occur through several pathways (namely MRD persistence at the end of treatment at a high level, MRD progression from a low level or MRD re-emergence during follow up; the latter two constitute MRD relapse as defined by the European Leukemia Net) and is clinically actionable, with survival benefit reported in AML subgroups. Selection of pre-emptive therapy at MRD failure relies upon an integrated clinico-molecular assessment and is subset-specific. In acute promyelocytic leukemia, arsenic trioxide-based regimen for MRD failure following frontline treatment with all-trans-retinoic acid plus chemotherapy represents standard of care, while hypomethylating agents (eg, azacitidine), salvage chemotherapy (eg, FLAG-IDA) and venetoclax-based regimens are effective in NPM1-mutated AML. Specific inhibitors of FLT3 have emerging use in FLT3-mutated AML and are associated with minimal toxicity. Furthermore, immunotherapeutic approaches such as donor lymphocyte infusions and interferon-⍺ are efficacious options in the post-allogeneic-HSCT settings. Enrollment into clinical trials with genomic-guided assignment of pre-emptive therapy at MRD failure should be prioritized. Finally, with the emergence of novel agents (eg, menin inhibitors) and approaches (eg, adoptive cellular and immunological therapy), an exciting future lies ahead where a broad array of highly active pre-emptive therapeutic options will likely be clinically applicable to a wide range of AML subsets.

Day-21 bone marrow findings incorrectly designate residual leukaemia in FLT3-mutated acute myeloid leukaemia treated with intensive induction plus midostaurin: a morphology-focused study.

Early induction response assessment with day-21 bone marrow (D21-BM) is commonly performed in patients with FLT3-mutated acute myeloid leukaemia (AML), where detection of residual leukaemia (RL; blasts ≥5%) typically results in the administration of a second induction course. However, whether D21-BM results predict for RL at the end of first induction has not been systematically assessed. This study evaluates the predictive role of D21-BM morphology in detecting RL following first induction. Between August 2018 and March 2022, all patients with FLT3-AML receiving 7+3 plus midostaurin, with D21-BM performed, were identified. Correlation between D21-BM morphology vs D21-BM ancillary flow/molecular results, as well as vs D28-BM end of first induction response, were retrospectively reviewed. Subsequently, D21-BMs were subjected to anonymised morphological re-assessments by independent haematopathologists (total in triplicate per patient). Of nine patients included in this study, three (33%) were designated to have RL at D21-BM, all of whom entered complete remission at D28-BM. Furthermore, only low-level measurable residual disease was detected in all three cases by flow or molecular methods at D21-BM, hence none proceeded to a second induction. Independent re-evaluations of these cases failed to correctly reassign D21-BM responses, yielding a final false positive rate of 33%. In summary, based on morphology alone, D21-BM assessment following 7+3 intensive induction plus midostaurin for FLT3-AML incorrectly designates RL in some patients; thus correlating with associated flow and molecular results is essential before concluding RL following first induction. Where remission status is unclear, repeat D28-BMs should be performed.

Clinical impact of NPM1-mutant molecular persistence after chemotherapy for acute myeloid leukemia.

Monitoring of NPM1 mutant (NPM1mut) measurable residual disease (MRD) in acute myeloid leukemia (AML) has an established role in patients who are treated with intensive chemotherapy. The European LeukemiaNet has defined molecular persistence at low copy number (MP-LCN) as an MRD transcript level <1% to 2% with a <1-log change between any 2 positive samples collected after the end of treatment (EOT). Because the clinical impact of MP-LCN is unknown, we sought to characterize outcomes in patients with persistent NPM1mut MRD after EOT and identify factors associated with disease progression. Consecutive patients with newly diagnosed NPM1mut AML who received ≥2 cycles of intensive chemotherapy were included if bone marrow was NPM1mut MRD positive at the EOT, and they were not transplanted in first complete remission. One hundred patients were followed for a median of 23.5 months; 42% remained free of progression at 1 year, either spontaneously achieving complete molecular remission (CRMRD-; 30%) or retaining a low-level NPM1mut transcript (12% for ≥12 months and 9% at last follow-up). Forty percent met the criteria for MP-LCN. Preemptive salvage therapy significantly prolonged relapse-free survival. Risk factors associated with disease progression were concurrent FLT3-internal tandem duplication at diagnosis and suboptimal MRD response (NPM1mut reduction <4.4-log) at EOT.

Excellent outcomes of transformed lymphomas in the rituximab era without autologous stem cell transplantation: an Australian single-centre experience.

BACKGROUND: Histologic transformation (HT) is an important event with adverse prognosis in the natural history of indolent lymphomas. There are minimal data on HT in the Australian setting. AIMS: To characterise patients with biopsy-proven HT and their outcomes identified at a tertiary Australian Hospital. METHODS: All patients with biopsy-proven HT during a 15-year period (2002-2017) were included. Clinico-pathological data were systematically collected from review of patient records. Survival estimates were assessed using the Kaplan-Meier method and compared using the log-rank test. Associations between variables and clinical outcomes were evaluated using Cox's proportional hazards model. RESULTS: A cohort of 45 patients was identified with a median age of 66 years and the majority (59%) having high-risk disease (Revised-International Prognostic Index score ≥3). R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, prednisolone) induction was used in 69%, with an overall response rate of 82% (complete response (CR), 75%). Sixty-one percent of these induction responders received consolidation, with autologous stem cell transplant (ASCT) performed in only 17% and rituximab maintenance given to 31%. With a median follow up of 47 months (range: 4-136), the 5-year overall survival (OS) was 69% (95% CI: 52%, 81%). Chemotherapy-naivety at HT was associated with a superior rate of CR (84% vs 54%, P = 0.057) and 5-year OS (82% vs 46%, P = 0.012). Rituximab maintenance was associated with a durable progression-free survival in induction responders. CONCLUSIONS: Excellent OS was observed in this modern cohort of patients treated with rituximab-containing induction and low rate of consolidation by ASCT, particularly in those who were chemotherapy-naïve at HT.

Ocular infiltration as initial presentation of acute monocytic leukaemia transformed from chronic myelomonocytic leukaemia associated with BRAF V600E mutation.

Acute monocytic leukaemia (French-British-American classification: AML-M5b) is characterised by a predominance of cells of the monocytic lineage on bone marrow examination. Furthermore, a discerning feature is its tendency for tissue infiltration. While gum hypertrophy and hepatosplenomegaly are common, ocular involvement is rare. Here, we present a case of a 75-year-old man referred with proptosis and monocytosis-subsequently diagnosed as AML-M5b, whose disease course was distinguished by extensive tissue invasion (ocular, pulmonary, liver, spleen). Cytogenetics and molecular tests were consistent with blastic transformation of previously undiagnosed chronic myelomonocytic leukaemia, supported by the presence of long-standing, low-grade monocytosis. Notably, a BRAF V600E mutation was also detected-an oncogenic driver previously reported in de novo and therapy-related, but not chronic myelomonocytic leukaemia-transformed, AML-M5b. While an initial response to cytoreductive treatment was observed, his tissue-invasive disease soon progressed with worsening pulmonary infiltrates, disseminated intravascular coagulation and renal failure, resulting in death.