The current World Health Organization classification of myelodysplastic syndromes is based morphological evaluation of bone marrow dysplasia. In clinical practice, the reproducibility of the ...recognition of dysplasia is usually poor especially in cases that lack specific markers such as ring sideroblasts and clonal cytogenetic abnormalities.
We aimed to develop and validate a flow cytometric score for the diagnosis of myelodysplastic syndrome. Four reproducible parameters were analyzed: CD34(+) myeloblast-related and B-progenitor-related cluster size (defined by CD45 expression and side scatter characteristics CD34(+) marrow cells), myeloblast CD45 expression and granulocyte side scatter value. The study comprised a "learning cohort" (n=538) to define the score and a "validation cohort" (n=259) to confirm its diagnostic value.
With respect to non-clonal cytopenias, patients with myelodysplastic syndrome had increased myeloblast-related cluster size, decreased B-progenitor-related cluster size, aberrant CD45 expression and reduced granulocyte side scatter (P<0.001). To define the flow cytometric score, these four parameters were combined in a regression model and the weight for each variable was estimated based on coefficients from that model. In the learning cohort a correct diagnosis of myelodysplastic syndrome was formulated in 198/281 cases (sensitivity 70%), while 18 false-positive results were noted among 257 controls (specificity 93%). Sixty-five percent of patients without specific markers of dysplasia (ring sideroblasts and clonal cytogenetic abnormalities) were correctly classified. A high value of the flow cytometric score was associated with multilineage dysplasia (P=0.001), transfusion dependency (P=0.02), and poor-risk cytogenetics (P=0.04). The sensitivity and specificity in the validation cohort (69% and 92%, respectively) were comparable to those in the learning cohort. The likelihood ratio of the flow cytometric score was 10.
A flow cytometric score may help to establish the diagnosis of myelodysplastic syndrome, especially when morphology and cytogenetics are indeterminate.
B cell–activation factor (BAFF) is critical for B cell maturation. Inhibition of BAFF represents an appealing target for desensitization of sensitized end‐stage renal disease (ESRD) patients. We ...conducted a Phase 2a, single‐arm, open‐label exploratory study investigating the effect of tabalumab (BAFF inhibitor) in patients with ESRD and calculated panel reactive antibodies (cPRAs) >50%. The treatment period duration was 24 weeks. Eighteen patients received tabalumab, at doses of 240‐mg subcutaneous (SC) at Week 0 followed by 120‐mg SC monthly for 5 additional months. Patients were followed for an additional 52 weeks. Immunopharmacologic effects were characterized through analysis of blood for HLA antibodies, BAFF concentrations, immunoglobulins, T and B cell subsets, as well as pre‐ and posttreatment tonsil and bone marrow biopsies. Significant reductions in cPRAs were observed at Weeks 16 (p = 0.043) and 36 (p = 0.004); however, absolute reductions were small (<5%). Expected pharmacologic changes in B cell subsets and immunoglobulin reductions were observed. Two tabalumab‐related serious adverse events occurred (pneumonia, worsening of peripheral neuropathy), while the most common other adverse events were injection‐site pain and hypotension. Three patients received matched deceased donor transplants during follow‐up. Treatment with a BAFF inhibitor resulted in statistically significant, but not clinically meaningful reduction in the cPRA from baseline (NCT01200290, Clinicaltrials.gov).
Treatment with a B cell–activating factor inhibitor in highly sensitized end‐stage kidney disease patients awaiting kidney transplant produces pharmacodynamic effects but does not lead to clinically meaningful reduction in calculated panel reactive antibodies.
Abstract
Casestudy: Pathologic diagnosis of chronic myelomonocytic leukemia (CMML) is typically straightforward with the majority of patients presenting with persistent monocytosis (>1x109/L, >=10%) ...and bone marrow dysplasia. The diagnosis may be challenging in patients with unusual features such as lack pf peripheral blood monocytosis and non-diagnostic bone marrow morphology. In this abstract, we present a 67-year-old female with a 5-year history of anemia of unclear etiology. At the time of initial presentation, the laboratory work-up of normocytic anemia was non- contributory, the bone marrow was reported as normocellular with maturing trilineage hematopoiesis and no significant dysplasia. Over the course of the disease, the peripheral blood monocyte count fluctuated from 11% to 18% with absolute monocyte count ranging from 0.4 to 0.7x109/L. The most recent bone marrow was markedly hypercellular with increased trilineage hematopoiesis with left shift, dysgranulopoiesis and dysmegakaryopoiesis. Blasts (including promonocytes) constituted 10% of the differential count and were immunophenotypically abnormal with uniform expression of CD117, dim to negative CD13, and partial CD15. Monocytes were elevated at 12% and were strongly positive for CD64 and partially for CD14. They were negative for CD16 consistent with classical monocytes, and showed partial loss of CD13. The karyotype was normal. Molecular testing revealed TET2, RELN and SRSF2 mutations at high allelic frequencies. This case illustrates a value of flow cytometric immunophenotyping and molecular genetic studies in diagnosing challenging cases of CMML. While the patient’s absolute monocyte count remained below the diagnostic threshold of 1x109/L throughout the course of the disease, peripheral blood and bone marrow monocytes showed skewed classical immunophenotype, immunophenotypic abnormalities of myeloid series and high allelic frequency mutations. These findings should raise a differential diagnosis of oligomonocytic CMML, even when morphologic abnormalities and monocyte count threshold are not diagnostic.
Splenic hamartoma is a rare tumor-like lesion composed of structurally disorganized red pulp elements. It has been hypothesized that two other splenic lesions, cord capillary hemangioma and myoid ...angioendothelioma, may fall within the spectrum of splenic hamartoma, simply representing morphological variants. In this study, we compared the vascular and stromal composition of cord capillary hemangioma and myoid angioendothelioma with those of classical hamartoma. In addition, we assessed the clonal vs polyclonal nature of the lesions in nine female cases by performing clonality analysis for X-chromosome inactivation at the human androgen receptor locus (HUMARA) on laser-assisted microdissected samples. In 15 of 17 cases, increased reticulin and/or collagen content was observed. The classical hamartoma cases showed a vasculature predominantly composed of CD8+ CD31+ CD34- splenic sinuses, whereas cases of cord capillary hemangioma and myoid angioendothelioma contained many CD8- CD31+ CD34+ cord capillaries, but very little CD8+ vasculature. All cases lacked expression of D2-40 and Epstein Barr virus-encoded RNA. All cases showed a proliferation index of ≤5% by Ki-67. Cases of classical hamartoma lacked significant perisinusoidal expression of collagen IV and low-affinity nerve growth factor receptor. Both markers were variably expressed in the other lesions. Increased CD163-positive histiocytes were found in four cases (three cord capillary hemangiomas and one myoid angioendothelioma). HUMARA analysis was informative in all nine tested cases, of which three cases showed a non-random X-chromosome inactivation pattern, indicating clonality. All three clonal cases were cord capillary hemangiomas. Our study has shown that in spite of considerable morphologic heterogeneity and overlapping features, classical hamartoma and cord capillary hemangioma and myoid angioendothelioma are different in terms of their vascular and stromal composition. Clonality analysis supports a true neoplastic origin for the cord capillary hemangioma. A larger study using additional immunohistochemical and molecular studies is necessary to further evaluate the biological significance of the current findings.
Abstract
Casestudy: Pediatric-type follicular lymphoma is crucial to differentiate from other subtypes of follicular lymphomas since it carries an excellent prognosis and generally does not require ...radio- or chemotherapy. We present a 22-year-old male with an 8-year history of a left submandibular mass. Interval imaging studies showed no change in the mass size over time and no other sites of involvement. The patient underwent excision of the mass. Histologic sections showed effacement of nodal architecture with expansile follicles composed of medium sized to large lymphoid cells with blastoid features. Follicles showed abundant tingible body macrophages. Polarization was not seen. Neoplastic follicles were positive for CD20, PAX5, BCL6, CD10, and FOXP1, and negative for BCL2. PD1 positive cells were localized peripherally in the follicles. Clonality was confirmed by flow cytometry (kappa restricted CD10 positive B-cells in a polyclonal background) and by IGH PCR analysis (clonal peaks in FR1 and FR2).
Molecular genetic testing showed the following mutations: TNFRSF14 W12* (VAF 14.8%), MAP2K1 F53V (5.7%), EZH2 Y646N (6.9%), ARID1A R1461* (7.1%). BCL2 rearrangement was not detected. MAP2K1 and TNFRSF1 are frequently reported in pediatric-type follicular lymphoma, however in the majority of cases they do not occur together. EZH2 mutation does not typically occur in pediatric-type follicular lymphoma, and is more common in classic adult- onset follicular lymphomas. Despite typical morphologic and clinical features, this patient showed a more complex genetic profile and EZH2 mutation, unusual findings in pediatric-type follicular lymphoma. It is conceivable that a higher genetic complexity has been acquired over time and is related to the long duration of the disease.
Gene expression profiling (GEP) has stratified diffuse large B-cell lymphoma (DLBCL) into molecular subgroups that correspond to different stages of lymphocyte development-namely germinal center ...B-cell like and activated B-cell like. This classification has prognostic significance, but GEP is expensive and not readily applicable into daily practice, which has lead to immunohistochemical algorithms proposed as a surrogate for GEP analysis. We assembled tissue microarrays from 475 de novo DLBCL patients who were treated with rituximab-CHOP chemotherapy. All cases were successfully profiled by GEP on formalin-fixed, paraffin-embedded tissue samples. Sections were stained with antibodies reactive with CD10, GCET1, FOXP1, MUM1 and BCL6 and cases were classified following a rationale of sequential steps of differentiation of B cells. Cutoffs for each marker were obtained using receiver-operating characteristic curves, obviating the need for any arbitrary method. An algorithm based on the expression of CD10, FOXP1 and BCL6 was developed that had a simpler structure than other recently proposed algorithms and 92.6% concordance with GEP. In multivariate analysis, both the International Prognostic Index and our proposed algorithm were significant independent predictors of progression-free and overall survival. In conclusion, this algorithm effectively predicts prognosis of DLBCL patients matching GEP subgroups in the era of rituximab therapy.
Abstract
Introduction/Objective
PAX5 is a transcription factor critical for B-cell development and its genetic alterations are common in B lymphoblastic leukemia/lymphoma (B-ALL). We report a case of ...PAX5 P80R mutated acute leukemia with predominantly monocytic immunophenotype followed by a genetically-related histiocytic proliferation.
Methods/Case Report
A 27-year-old male presented with pancytopenia, epistaxis, and blurry vision. Bone marrow exam showed 95% blasts with nuclear indentations, occasional prominent nucleoli and basophilic cytoplasm. Blasts were positive for bright CD33, HLA-DR, CD14, bright CD64, partial CD123 and partial CD19. In addition, a minute population of B lymphoblasts positive for CD19, CD20, and dim TdT was seen. The AML FISH panel showed markedly aneuploid population with all probes demonstrating 3 to 5 signals. PAX5 P80R and KRAS G13D mutations were detected by NGS. Post induction bone marrow showed no evidence of acute leukemia with normal cytogenetics and FISH results. Subsequent two bone marrow exams performed due to progressive cytopenias demonstrated a prominent histiocytic proliferation with sheets of mature appearing histiocytes with abundant cytoplasm, oval to folded nuclei and occasional hemophagocytosis. This population was positive for CD163, CD14, CD68R, CD68, cyclin D1 with variable OCT2 expression and low proliferative activity. PAX5 P80R and KRAS G13D were detected. AML FISH panel showed aneuploidy in histiocytic appearing cells and IgH gene rearrangement studies by PCR showed prominent clonal population. The patient remained pancytopenic and died of disseminated fungal infection.
Results (if a Case Study enter NA)
NA
Conclusion
PAX5 P80R mutation has been primarily reported in B-ALL and is exceedingly rare in acute myeloid leukemias. This alteration has been linked to downregulation of B-cell lineage genes affecting B-cell maturation, and not surprisingly a proportion of PAX5 P80R mutated B-ALL cases show a switch to a monocytic lineage. The reported case demonstrates diagnostic caveats including unusual features of acute leukemia at the time of initial diagnosis and subsequent genetically-related histiocytic proliferation.
Therapy-Related Myeloid Neoplasms CZADER, Magdalena; ORAZI, Attilio
American journal of clinical pathology,
09/2009, Volume:
132, Issue:
3
Journal Article
Peer reviewed
Open access
Session 5 of 2007 Workshop of the Society for Hematopathology/European Association for Haematopathology focused on therapy-related myeloid neoplasms. This report discusses the diversity and relevance ...of clinical, pathologic, and genetic features and provides an update on the pathogenesis of these disorders. We highlight common diagnostic issues such as the differentiation between therapy-related myelodysplastic syndrome and therapy-related acute erythroid leukemia. As similar therapeutic interventions are frequently considered for patients with either of these diagnoses, in the current World Health Organization classification, regardless of morphologic presentation, therapy-related myeloid neoplasms are considered together as a unique clinicopathologic syndrome of therapy-related myelodysplastic syndrome/acute myeloid leukemia. Nevertheless, recognition of the diverse morphologic features is crucial as bone marrow morphologic examination remains the first and important step of patient evaluation. We also present examples of therapy-related acute myeloid leukemias with recurrent cytogenetic abnormalities. In these cases, the precise classification is clinically important because it is associated with distinct clinical outcome.
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