Invasive fungal infection caused by Blastobotrys mokoenaii in an immunocompromised patient with acute myeloid leukemia: A case report.

Blastobotrys is a genus of rare yeast that is increasingly recognized as a cause of fungal infections in humans. However, there have been no reports of fungal infections in humans caused by Blastobotrys mokoenaii. We describe a case of invasive fungal infection (IFI) caused by B. mokoenaii in an immunocompromised patient with acute myeloid leukemia (AML). A 46-year-old man with relapsed/refractory AML underwent a second allogeneic peripheral blood hematopoietic stem cell transplantation (allo-PBSCT) during remission. The patient had prolonged neutropenia and received systemic steroid therapy for graft-versus-host disease before the second allo-PBSCT. Uncommon yeast was isolated from the blood cultures obtained on day 4. We initially suspected that the uncommon yeast was Trichosporon spp. based on its morphology. However, unlike Trichosporon spp., in vitro antifungal susceptibility tests showed that this yeast isolate was resistant to micafungin, caspofungin, voriconazole, itraconazole, and fluconazole. We performed DNA sequencing and identified it as B. mokoenaii. B. mokoenaii was persistently isolated from blood cultures taken during combination therapy with liposomal amphotericin B and voriconazole. The patient died of multiorgan failure on day 24. B. mokoenaii can cause severe IFI in immunocompromised patients; however, it may not be correctly identified by routine clinical microbiology testing in a hospital laboratory and DNA sequencing is useful for diagnosis.

Effectiveness of venetoclax and azacytidine against myeloid/natural killer cell precursor acute leukemia.

Myeloid/natural killer (NK) cell precursor acute leukemia (MNKPL) is a rare leukemia subtype that possibly originates from precursor NK cells. The disease has a poor prognosis, and information on its treatment is lacking. We herein report the first case of a 46-year-old woman with MNKPL who was refractory to two lines of acute myeloid leukemia (AML)-type intensive chemotherapy but was successfully treated with venetoclax and azacytidine (VEN/AZA). She was diagnosed with MNKPL based on the conformations of immature lymphoblastoid morphology without myeloperoxidase reactivity that showed a CD7/CD33/CD34/CD56/HLA-DR positive phenotype and extramedullary regions. The disease was refractory to induction therapy with daunorubicin and cytarabine (DNR/Ara-C) and to reinduction therapy with mitoxantrone, etoposide, and cytarabine (MEC). After two lines of induction chemotherapy, massive pericardial and pleural effusion was found, and was suspected to be extramedullary lesions. The patient developed cardiac tamponade and required pericardiocentesis. Thus, VEN/AZA was administered as third-line therapy. After two cycles of VEN/AZA, the pericardial and pleural effusion disappeared, and complete remission was achieved. The patient received post-transplant cyclophosphamide-based haploidentical transplantation and has stayed relapse-free as of her last follow-up examination 2 years after diagnosis.