Evaluation of [18F]-FDG-Based Hybrid Imaging Combinations for Assessment of Bone Marrow Involvement in Lymphoma at Initial Staging.

The purpose of our study was to determine the value of different hybrid imaging combinations for the detection of focal and diffuse bone marrow infiltration in lymphoma. Patients with histologically proven lymphoma, who underwent both [18F]-FDG-PET/CT and whole-body MRI (including T1- and diffusion-weighted [DWI] sequences) within seven days, and a subsequent bone marrow biopsy, were retrospectively included. Three hybrid imaging combinations were evaluated: (1) [18F]-FDG-PET/CT; (2) [18F]-FDG-PET/T1; and (3) [18F]-FDG-PET/DWI. The presence of focal or diffuse bone marrow infiltration was assessed by two rater teams. Sensitivity, specificity, and accuracy for the detection of overall, focal, and diffuse bone marrow involvement were compared between the three hybrid imaging combinations. Overall, lymphomatous bone marrow involvement was found in 16/60 patients (focal, 8; diffuse, 8). Overall sensitivity, specificity, and accuracy were 81.3%, 95.5%, and 91.7% for [18F]-FDG-PET/CT; 81.3%, 97.7%, and 93.3% for [18F]-FDG-PET/T1; and 81.3%, 95.5%, and 91.7% for [18F]-FDG-PET/DWI. No statistically significant differences between the three imaging combinations were observed, based on overall bone marrow involvement, focal involvement, or diffuse involvement. The sensitivity of all three imaging combinations for detecting diffuse bone marrow involvement was only moderate (62.5% for all three combinations). Although the combination of [18F]-FDG-PET and T1-weighted MRI generally showed the best diagnostic performance for the detection of bone marrow involvement in lymphoma, it was not significantly superior to the two other hybrid imaging combinations. Since the sensitivity of all imaging combinations for the detection of diffuse bone marrow involvement was only moderate, bone marrow biopsy cannot be replaced by imaging as yet

Sporadic Creutzfeldt-Jakob disease VM1: phenotypic and molecular characterization of a novel subtype of human prion disease

The methionine (M)-valine (V) polymorphic codon 129 of the prion protein gene (PRNP) plays a central role in both susceptibility and phenotypic expression of sporadic Creutzfeldt-Jakob diseases (sCJD). Experimental transmissions of sCJD in humanized transgenic mice led to the isolation of five prion strains, named M1, M2C, M2T, V2, and V1, based on two major conformations of the pathological prion protein (PrPSc, type 1 and type 2), and the codon 129 genotype determining susceptibility and propagation efficiency. While the most frequent sCJD strains have been described in codon 129 homozygosis (MM1, MM2C, VV2) and heterozygosis (MV1, MV2K, and MV2C), the V1 strain has only been found in patients carrying VV. We identified six sCJD cases, 4 in Catalonia and 2 in Italy, carrying MV at PRNP codon 129 in combination with PrPSc type 1 and a new clinical and neuropathological profile reminiscent of the VV1 sCJD subtype rather than typical MM1/MV1. All patients had a relatively long duration (mean of 20.5 vs. 3.5 months of MM1/MV1 patients) and lacked electroencephalographic periodic sharp-wave complexes at diagnosis. Distinctive histopathological features included the spongiform change with vacuoles of larger size than those seen in sCJD MM1/MV1, the lesion profile with prominent cortical and striatal involvement, and the pattern of PrPSc deposition characterized by a dissociation between florid spongiform change and mild synaptic deposits associated with coarse, patch-like deposits in the cerebellar molecular layer. Western blot analysis of brain homogenates revealed a PrPSc type 1 profile with physicochemical properties reminiscent of the type 1 protein linked to the VV1 sCJD subtype. In summary, we have identified a new subtype of sCJD with distinctive clinicopathological features significantly overlapping with those of the VV1 subtype, possibly representing the missing evidence of V1 sCJD strain propagation in the 129MV host genotype

Successful Clarithromycin Monotherapy in a Patient with Primary Follicular Lymphoma of the Duodenum

Primary follicular lymphoma of the duodenum (FL-D) constitutes a rare subtype of extranodal follicular lymphoma with a usually indolent course. To date, no distinct treatment recommendations have been defined for those patients. We report the case of a 58-year-old male patient presenting with endoscopically assessed, symptomatic FL-D who was treated with clarithromycin monotherapy in analogy to recent data for mucosa-associated lymphoid tissue lymphoma. Each treatment cycle consisted of clarithromycin 500 mg twice daily for 3 weeks followed by a 2-week break. After four cycles of treatment, the patient showed a very good response with normal macroscopic findings confirmed by endosonographic examination and only focal minimal residual disease of lymphoma persisting in the histological assessment. The patient is currently asymptomatic and without treatment for 24+ months. As clarithromycin combines antimicrobial and direct antiproliferative effects mediated through a variety of pleiotropic mechanisms, this appears to be an interesting treatment approach for indolent lymphoma, particularly in those where a chronic infectious background cannot be completely ruled out, i.e., gastrointestinal manifestations. We suggest further investigation of this treatment approach.(VLID)471538