An unusual association between splenectomy and Kikuchi's disease

Kikuchi's disease is a clinico-pathologic entity of unknown etiology characterized by subacute inflammatory process of lymph nodes. It affects mostly women around the age of 30 years. It is usually a self limiting illness characterized by pyrexia, neutropenia, and cervical lymphadenopathy. We report a case of Kikuchi's disease in a patient with past history of splenectomy. A 35-year-old otherwise healthy female patient presented with 15 days history of fever, night sweats, and right cervical lymphadenopathy. She was on no medication and had no contact with animals or patients with tuberculosis. Her past history revealed splenectomy for thrombocytopenia 14 years before presentation. Lymphoma was suspected and she was referred for a cervical lymph node biopsy. The final histopathology diagnosis revealed subacute necrotizing lymphadenitis consistent with Kikuchi's disease. This is the first case of Kikuchi's disease presenting in a post splenectomy patient.     

An unusual case of giant cardiac fibroelastoma mimicking left atrial myxoma in a patient presenting with syncope

Cardiac papillary fibroelastomas are the most common primary valvular tumors. Generally benign, they account only for about 10% of all primary cardiac neoplasms, can occur in normal or diseased hearts, and are associated strongly with open heart surgery and radiotherapy. They are, in most cases, incidental findings, but can be discovered after syncope. We report the case of an elderly female, who was referred for syncope and was found to have a large fibroelastoma at the mitral valve annulus, intermittently obstructing the left ventricular inflow tract, and mimicking the presentation of left atrial myxoma. This case illustrates another potential mechanism of syncope in patients with fibroelastomas. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2013     

Chemotherapeutic agents circumvent emergence of dasatinib-resistant BCR-ABL kinase mutations in a precise mouse model of Philadelphia chromosome-positive acute lymphoblastic leukemia

The introduction of cultured p185(BCR-ABL)-expressing (p185+) Arf (-/-) pre-B cells into healthy syngeneic mice induces aggressive acute lymphoblastic leukemia (ALL) that genetically and phenotypically mimics the human disease. We adapted this high-throughput Philadelphia chromosome-positive (Ph(+)) ALL animal model for in vivo luminescent imaging to investigate disease progression, targeted therapeutic response, and ALL relapse in living mice. Mice bearing high leukemic burdens (simulating human Ph(+) ALL at diagnosis) entered remission on maximally intensive, twice-daily dasatinib therapy, but invariably relapsed with disseminated and/or central nervous system disease. Although relapse was frequently accompanied by the eventual appearance of leukemic clones harboring BCR-ABL kinase domain (KD) mutations that confer drug resistance, their clonal emergence required prolonged dasatinib exposure. KD P-loop mutations predominated in mice receiving less intensive therapy, whereas high-dose treatment selected for T315I "gatekeeper" mutations resistant to all 3 Food and Drug Administration-approved BCR-ABL kinase inhibitors. The addition of dexamethasone and/or L-asparaginase to reduced-intensity dasatinib therapy improved long-term survival of the majority of mice that received all 3 drugs. Although non-tumor-cell-autonomous mechanisms can prevent full eradication of dasatinib-refractory ALL in this clinically relevant model, the emergence of resistance to BCR-ABL kinase inhibitors can be effectively circumvented by the addition of "conventional" chemotherapeutic agents with alternate antileukemic mechanisms of action.     

Reactivation of latent Toxoplasma gondii in immunocompromised cancer patients

Active Toxoplasma gondii infection in cancer patients undergoing anticancer chemotherapy was evaluated using both enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR) techniques. Ninety-nine cancer patients were studied. Sixty seven of those patients were under cancer chemotherapy treatment, 41 (61.2%) of which were found to be ELISA immunoglobulin g (IgG) positive and five (7.5%) were PCR positive. On the other hand, none of the 32 untreated cancer patients was found to be PCR positive although 22 (68.7%) of them were ELISA IgG positive. These findings suggest the possibility that treatment with immunosuppressive agents predisposed cancer patients to reactivation of T. gondii infection.     

Myocardial first‐pass perfusion: Influence of spatial resolution and heart rate on the dark rim artifact

Myocardial perfusion images can be affected by the dark rim artifact. This study aimed to evaluate the effects of the spatial resolution and heart rate on the transmural extent of the artifact. Six pigs under anesthesia were scanned at 1.5T using an echo‐planar imaging/fast gradient echo sequence with a nonselective saturation preparation pulse. Three short‐axis slices were acquired every heart beat during the first pass of a contrast agent bolus. Two different in‐plane spatial resolutions (2.65 and 3.75 mm) and two different heart rates (normal and tachycardia) were used, generating a set of four perfusion scans. The percentage drop of signal in the subendocardium compared to the epicardium and the transmural extent of the artifact were extracted. Additionally, the signal‐to‐noise and the contrast‐to‐noise ratios were evaluated. The signal drop as well as the width of the dark rim artifact increased with decreased spatial resolution and with increased heart rates. No significant slice‐to‐slice variability was detected for signal drop and width of the rim within the four considered groups. signal‐to‐noise ratio (SNR) and contrast‐to‐noise ratio (CNR) ratios decreased with increasing spatial resolution. In conclusion, low spatial and temporal resolution could be correlated with increased extent of the dark‐rim artifact and with lower SNR and CNR. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.     

Superior diagnostic performance of perfusion-cardiovascular magnetic resonance versus SPECT to detect coronary artery disease: The secondary endpoints of the multicenter multivendor MR-IMPACT II (Magnetic Resonance Imaging for Myocardial Perfusion Assessment in Coronary Artery Disease Trial)

Background

Perfusion-cardiovascular magnetic resonance (CMR) is generally accepted as an alternative to SPECT to assess myocardial ischemia non-invasively. However its performance vs gated-SPECT and in sub-populations is not fully established. The goal was to compare in a multicenter setting the diagnostic performance of perfusion-CMR and gated-SPECT for the detection of CAD in various populations using conventional x-ray coronary angiography (CXA) as the standard of reference.

Methods

In 33 centers (in US and Europe) 533 patients, eligible for CXA or SPECT, were enrolled in this multivendor trial. SPECT and CXA were performed within 4 weeks before or after CMR in all patients. Prevalence of CAD in the sample was 49% and 515 patients received MR contrast medium. Drop-out rates for CMR and SPECT were 5.6% and 3.7%, respectively (ns). The study was powered for the primary endpoint of non-inferiority of CMR vs SPECT for both, sensitivity and specificity for the detection of CAD (using a single-threshold reading), the results for the primary endpoint were reported elsewhere. In this article secondary endpoints are presented, i.e. the diagnostic performance of CMR versus SPECT in subpopulations such as multi-vessel disease (MVD), in men, in women, and in patients without prior myocardial infarction (MI). For diagnostic performance assessment the area under the receiver-operator-characteristics-curve (AUC) was calculated. Readers were blinded versus clinical data, CXA, and imaging results.

Results

The diagnostic performance (= area under ROC = AUC) of CMR was superior to SPECT (p = 0.0004, n = 425) and to gated-SPECT (p = 0.018, n = 253). CMR performed better than SPECT in MVD (p = 0.003 vs all SPECT, p = 0.04 vs gated-SPECT), in men (p = 0.004, n = 313) and in women (p = 0.03, n = 112) as well as in the non-infarct patients (p = 0.005, n = 186 in 1–3 vessel disease and p = 0.015, n = 140 in MVD).

Conclusion

In this large multicenter, multivendor study the diagnostic performance of perfusion-CMR to detect CAD was superior to perfusion SPECT in the entire population and in sub-groups. Perfusion-CMR can be recommended as an alternative for SPECT imaging.

Trial registration

ClinicalTrials.gov, Identifier: {"type":"clinical-trial","attrs":{"text":"NCT00977093","term_id":"NCT00977093"}}NCT00977093