False-negative solid-phase platelet crossmatch results due to prozone phenomenon.

Prozone is a known phenomenon affecting immunoassays causing falsely low or negative results when excess target is present in the test system. For assays used to evaluate immune-mediated platelet (PLT) transfusion refractoriness, prozone-like phenomenon has been described in solid-phase human leukocyte antigen (HLA) antibody testing and can be mitigated by diluting samples or pretreating samples with ethylenediaminetetraacetic acid (EDTA) or dithiothreitol. Prozone phenomenon has not yet been described in solid-phase red blood cell (RBC) adherence PLT crossmatch assays. CASE REPORT: A 40-year-old female with myeloid sarcoma and PLT transfusion refractoriness underwent repeated solid-phase PLT crossmatches; however, crossmatch-compatible PLTs units did not yield adequate PLT count responses. Class I HLA antibody testing with neat, diluted, and EDTA-pretreated serum demonstrated significant prozone-like effect and the presence of numerous high strength HLA antibodies. Based on this HLA antibody profile, HLA antigen-negative PLTs gave an adequate PLT count response. It was noted that the HLA types of her crossmatch-compatible PLTs were incompatible with her HLA antibody profile (eg, HLA-A2). With ABO-identical, HLA-A2-positive PLT units, a solid-phase PLT crossmatch was repeated using undiluted and diluted EDTA plasma. Undiluted EDTA plasma demonstrated negative or weakly positive PLT crossmatches while the diluted EDTA plasma demonstrated strongly positive PLT crossmatches. CONCLUSION: The prozone phenomenon can cause false-negative results in solid-phase RBC adherence PLT crossmatch assays, which can be mitigated with sample dilution. In immune-mediated PLT transfusion-refractory patients with high-strength HLA antibodies, sample dilution should be considered to correctly identify compatible PLT inventory.

Morphological characteristics, cytogenetic profile, and outcome of RUNX1-RUNX1T1-positive acute myeloid leukemia: Experience of an Indian tertiary care center.

INTRODUCTION: A prototype of good prognosis, t(8;21)-positive AML, has diverse clinical and genetic features which affect its outcome. This study aimed at evaluating the clinico-pathological spectrum of t(8;21)-positive AML and ascertaining prognostic factors influencing its outcome in the Indian subcontinent. METHODS: A retrospective analysis of 75 cases of t(8;21)-positive AML diagnosed over a period of six years (2013-2018) was carried out. Detailed clinical and laboratory data of the patients were collected from the electronic medical records and reviewed. RESULTS: Median age was 19.5 years (range 5-75 years) with a M:F of 1.7. Myeloid sarcoma was observed in 9.3% cases. There were 85% FAB AML-M2, 8% AML-M1, and 7% AML-M4 subtypes. Prominent morphological characteristics included dyspoiesis in maturing myeloid cells (83%), long thin tapered Auer rods (58%), cytoplasmic vacuoles (58%), eosinophilia (50%), and mast cells (22%). Auer rods in maturing granulocytes (4% cases) were highly suggestive of the translocation. Additional cytogenetic abnormalities were present in 53% cases. Seventy-one percent (25/35) achieved CR. The overall survival (OS) was 40%, with a median follow-up of 27 months (range 4-57 months). None of the hematological or cytogenetic factors correlated with OS, except for the presence of myeloid sarcoma which had a trend toward poor survival (P = .07). CONCLUSION: Outcome of t(8;21) AML is not influenced by any of the clinico-pathological parameters, except for a myeloid sarcoma, which may herald a poor prognosis. Recognition of this distinct subtype of AML would facilitate further molecular screening for risk stratification in resource-constrained settings.

Genomic aberrations in myeloid sarcoma without blood or bone marrow involvement: characterization of formalin-fixed paraffin-embedded samples by chromosomal microarrays.

Myeloid sarcoma (MS) is a presentation of acute myeloid leukemia (AML) as a tumor mass outside of the bone marrow. Viable cells from MS are frequently unavailable for cytogenetic studies. We therefore investigated whether chromosomal microarray analysis (CMA) using formalin-fixed paraffin-embedded (FFPE) tissues can detect clinically important genetic abnormalities in MS. CMA successfully identified genomic aberrations in six cases of MS, and in two cases it revealed multiple abnormalities equivalent to a complex karyotype, thus predicting a poor outcome. CMA using FFPE material is therefore a feasible and clinically applicable approach for detection of prognostically significant genomic abnormalities in MS.

Granulocytic sarcoma of the ovotestis: an association of myelodysplastic syndrome and hermaphroditism.

Granulocytic sarcomas are extramedullary tumors (EMD) of malignant myeloid precursor cells. EMD or granulocytic sarcoma of ovary is rare disease. A 15-year-old girl had complaints of abdominal pain and weight loss for 3 months. On physical examination, there were hepatosplenomegaly and a painless mass under the umbilicus. Breast development was grade II. There was no clitoris hypertrophy. Her labia majora were separate and vagina hypoplastic. Hemoglobin level was 9.3 g/dl, white blood cells count 2.8 x 10(6)/1, platelet count 31.6 x 10(9)/1. There were dysplastic features in the blood and bone marrow cells. There were 10 and 22% blasts in the peripheral blood smear and bone marrow, respectively. The levels of serum follicle stimulating and luteinizing hormones were high. An inguinal mass (diameter 9.5 x 7.6) cm was detected on computed tomography. The histopathological diagnosis of this was obtained from laporascopy was composed of ovotestis and there was marked blastic infiltration in this ovotestis which had myeloid markers on flow cytometry. In the immunohistochemical analyses of ovotestis and bone marrow, blasts were positive for LCA, CD-13, CD-33 and CD 68. The cytogenetic analysis of the bone marrow shaved 46 XY karyotype. No response was achieved with combination chemotherapy and the patient died from progressive leukemia. Here we report a rare patient with myelodysplastic syndrome, EMD and hermaphroditism. To our knowledge this is the first case of MDS, EMD and hermaphroditism.

Childhood proptosis: the invaluable but overlooked peripheral blood smear.

Two cases of granulocytic sarcoma presenting as childhood proptosis are described. This highlights the significance of peripheral blood smear examination in establishing the diagnosis of Acute Myeloid Leukaemia (AML).