[Show abstract][Hide abstract] ABSTRACT: The diagnosis of infectious mononucleosis (acute Epstein-Barr virus (EBV) infection) is usually made on the basis of clinical and laboratory findings. However, an atypical clinical presentation occasionally results in a lymph node or tonsillar biopsy. The morphological features of EBV-infected lymphoid tissue can easily mimic lymphoma. Furthermore, the immunophenotype of the immunoblasts has not been well characterized. To assess the morphological spectrum of acute EBV infection and the utility of immunohistochemistry in diagnosing difficult cases that resemble lymphoma, we reviewed 18 cases of acute EBV infection submitted in consultation to our institution with an initial diagnosis of/or suspicion for lymphoma. Patients included nine male and nine female individuals with a median age of 18 years (range 9-69). Biopsies were obtained from lymph nodes (3/18) or Waldeyer's ring (15/18). Infectious mononucleosis was confirmed by monospot or serological assays in 72% of cases (13/18). All cases featured architectural distortion by a polymorphous infiltrate with an immunoblastic proliferation, sometimes forming sheets. Reed-Sternberg-like cells were present in 8/18 (44%) of the cases. Infiltrates were often accompanied by necrosis (10/18) and mucosal ulceration (6/15). The majority of immunoblasts in all cases were CD20+ B cells with a post-germinal center immunophenotype (strongly positive for MUM1/IRF4 (18/18), CD10- (18/18 negative) and BCL-6- (16/18 negative; 2/18 faint BCL-6 expression in <10% of immunoblasts)). Immunoblasts showed variable weak expression of BCL-2 and polyclonal expression of κ and λ immunoglobulin light chains in 81% cases. Reed-Sternberg-like cells in 8/8 cases were CD30+, CD15-, BOB.1+ and OCT-2+. In conclusion, an atypical lymphoid infiltrate with numerous MUM1+, CD10-, BCL-6- immunoblasts should raise the suspicion of a reactive process, such as infectious mononucleosis, and warrants additional consideration before a diagnosis of lymphoma is made.
Modern Pathology 05/2012; 25(8):1149-59. · 5.25 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Intracerebral hemorrhage (ICH) contributes significantly to the morbidity and mortality of patients suffering from acute leukemia. While ICH is often identified in autopsy studies of leukemic patients, it is rare for ICH to be the presenting sign that ultimately leads to the diagnosis of leukemia. We report a patient with previously undiagnosed acute precursor B-cell lymphoblastic leukemia (ALL) who presented with diffuse encephalopathy due to ICH in the setting of an acute blast crisis. The diagnosis of ALL was initially suspected, because of the hyperleukocytosis observed on presentation, then confirmed with a bone marrow biopsy and flow cytometry study of the peripheral blood. Furthermore, detection of the BCR/ABL Philadelphia translocation t(9:22)(q34:q11) in this leukemic patient by fluorescent in situ hybridization permitted targeted therapy of the blast crisis with imatinib (Gleevec). Understanding the underlying etiology of ICH is pivotal in its management. This case demonstrates that the presence of hyperleukocytosis in a patient with intracerebral hemorrhage should raise clinical suspicion for acute leukemia as the cause of the ICH.
Clinical neurology and neurosurgery 09/2010; 112(7):575-7. · 1.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Histone deacetylase inhibitors (HDACI), can improve survival after lethal hemorrhagic shock, and modulate the inflammatory response after hemorrhage/lipopolysaccharide (LPS). The current experiments were designed to study the effects of HDACI after hemorrhage and severe hypoxia.
Splenic leukocytes from trauma and non-trauma patients (n=4-5/group) were exposed to severe hypoxia with/without suberoylanilide hydroxamic acid (SAHA, 400 nM) for 8h. Cytokines were measured by ELISA and RT-PCR, and hypoxia inducible factor (HIF)-1a and heme oxygenase (HO)-1 by Western blot.
After hemorrhage and hypoxia, SAHA increased IL-1b gene (4.7+/-1.2-fold) and protein expression (2.1+/-0.6-fold) in trauma splenic leukocytes. It also reduced IL-10 gene expression (0.6+/-0.2-fold), but did not alter TNFa or IL-6 levels. This unexpected pro-inflammatory response may be due to a decrease in HIF-1a and HO-1 protein levels.
In this model of severe hypoxia, treatment with SAHA increased the inflammatory response in trauma leukocytes, possibly through inhibition of the HIF-1/HO-1 pathway. Splenic leukocytes from non-trauma patients were variably affected by SAHA. Taken in context with the known anti-inflammatory properties of HDACI after hemorrhage/LPS, these findings suggest that the immune-modulating functions of HDACI are dependent on the type and severity of both the priming injury and subsequent insult.
[Show abstract][Hide abstract] ABSTRACT: Hemorrhage induces an imbalance in histone acetyl transferase/histone deacetylase (HAT/HDAC) ratio. Correction of this imbalance with histone deacetylase inhibitors (HDACI) improves survival. We aimed to identify whether this was due to modulation of the post-shock immune response.
We established a "two-hit" model in which rats (n=11; 5-6/group) and humans (n=10; 5/group) sustained trauma/hemorrhage, followed by exposure of splenic leukocytes to lipopolysaccharide (LPS, 10 ng/mL) for 8 or 24 hours. The leukocytes were treated with: No treatment, SAHA (suberoylanilide hydroxamic acid, HDACI, 400 nM), or Garcinol (HAT inhibitor, 20 microM).
Hemorrhage in the animals produced severe shock and a pro-inflammatory state. SAHA reduced TNFa secretion in the hemorrhaged leukocytes after LPS "second-hit" (34.0%, P = .003), whereas it increased transcript levels of TNFa and IL-1b (2.1+/-0.3 and 5.1+/- 2.2 fold respectively, P < .05). Leukocytes from trauma patients displayed 2 distinct responses to SAHA after LPS "second-hit," with markedly increased or decreased cytokine levels.
SAHA normalizes TNFa levels following hemorrhage and LPS "second hit" in the rats, whereas trauma patients respond to SAHA in 2 distinct patterns, with either marked attenuation or exaggeration of inflammatory cytokines. Cytokine levels were independent of gene expression, implicating acetylation of non-nuclear proteins as the dominant regulatory mechanism.
Surgery 08/2008; 144(2):204-16. · 3.37 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The present study analysed the clinicopathological features of nine myelodysplastic syndrome (MDS) patients in which del(20q) was the sole cytogenetic abnormality and a control group of 17 adult patients with idiopathic thrombocytopenic purpura (ITP). Seven of nine del(20q) patients were thrombocytopenic and six of nine were mildly anaemic at presentation. There was no significant morphological dysplasia identified in the del(20q) group as compared with the ITP group. These results indicate that MDS with del(20q) commonly presents with thrombocytopenia and has minimal morphological dysplasia. Cytogenetic analysis on adult patients undergoing bone marrow sampling for thrombocytopenia may help avoid misdiagnosis of MDS with del(20q) as ITP.
British Journal of Haematology 11/2007; 139(2):265-8. · 4.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We performed a multi-institutional retrospective analysis of the morphologic features, immunophenotype, cytogenetics, and BCR-ABL transcript characterization of cases of Philadelphia chromosome-positive acute myeloid leukemia (Ph+ AML). We compared these cases with cases of documented chronic myelogenous leukemia in myeloid blast crisis (CML-MBC). Patients with Ph+ AML were less likely to have splenomegaly or peripheral basophilia and had lower bone marrow cellularity and myeloid/erythroid ratios than patients with CML-MBC. Additional specific cytogenetic abnormalities that typically occur in CML-MBC were less common in Ph+ AML. Of 7 patients with Ph+ AML treated with imatinib mesylate, 6 showed at least a partial hematologic response, but the responses were of a short duration (median, 2.5 months). The median survival of patients with Ph+ AML was 9 months, similar to that of patients with CML-MBC (7 months). Ph+ AML is a rare aggressive acute leukemia with some features distinct from CML-MBC.
American Journal of Clinical Pathology 05/2007; 127(4):642-50. · 2.88 Impact Factor