Michael Schvimer

Diffusion Tensor Magnetic Resonance Imaging of the Pancreas

Purpose To develop a diffusion-tensor-imaging (DTI) protocol that is sensitive to the complex diffusion and perfusion properties of the healthy and malignant pancreas tissues. Materials and Methods Twenty-eight healthy volunteers and nine patients with pancreatic-ductal-adenocacinoma (PDAC), were scanned at 3T with T2-weighted and DTI sequences. Healthy volunteers were also scanned with multi-b diffusion-weighted-imaging (DWI), whereas a standard clinical protocol complemented the PDAC patients’ scans. Image processing at pixel resolution yielded parametric maps of three directional diffusion coefficients λ1, λ2, λ3, apparent diffusion coefficient (ADC), and fractional anisotropy (FA), as well as a λ1-vector map, and a main diffusion-direction map. Results DTI measurements of healthy pancreatic tissue at b-values 0,500 s/mm2yielded: λ1 = (2.65±0.35)×10−3, λ2 = (1.87±0.22)×10−3, λ3 = (1.20±0.18)×10−3, ADC = (1.91±0.22)×10−3 (all in mm2/s units) and FA = 0.38±0.06. Using b-values of 100,500 s/mm2 led to a significant reduction in λ1, λ2, λ3 and ADC (p<.0001) and a significant increase (p<0.0001) in FA. The reduction in the diffusion coefficients suggested a contribution of a fast intra-voxel-incoherent-motion (IVIM) component at b≤100 s/mm2, which was confirmed by the multi-b DWI results. In PDACs, λ1, λ2, λ3 and ADC in both 0,500 s/mm2 and 100,500 s/mm2 b-values sets, as well as the reduction in these diffusion coefficients between the two sets, were significantly lower in comparison to the distal normal pancreatic tissue, suggesting higher cellularity and diminution of the fast-IVIM component in the cancer tissue. Conclusion DTI using two reference b-values 0 and 100 s/mm2 enabled characterization of the water diffusion and anisotropy of the healthy pancreas, taking into account a contribution of IVIM. The reduction in the diffusion coefficients of PDAC, as compared to normal pancreatic tissue, and the smaller change in these coefficients in PDAC when the reference b-value was modified from 0 to 100 s/mm2, helped identifying the presence of malignancy.

Cavernous Hemangioma of Spermatic Cord Report of a Case With Immunohistochemical Study

We present a case of spermatic cord cavernous hemangioma. A 32-year-old man presented with a circumscribed, painless mass in the left side of the spermatic cord. An orchiectomy of the left testicle was performed. A 3 x 3 x 2.5-cm mass was present in the spermatic cord area. Histologic examination and immunohistochemical study showed a benign vascular tumor composed of vascular spaces of varying size. Although cavernous hemangioma can occur in any location, the spermatic cord is an extremely rare site, and, to our knowledge, only a few cases have been previously reported.

Prevalence and correlates of human papillomavirus genotypes among patients with cervical cancer and cervical intraepithelial neoplasia 3 in Israel.

Objectives This study aimed to assess the prevalence of human papillomavirus (HPV) in Israeli patients with cervical cancer and cervical intraepithelial neoplasia 3 (CIN3), to describe the distribution of the virus genotypes among positive cases, to characterize patients positive to HPV and, in particular, patients positive to HPV-16 and/or -18, and to evaluate the possible contribution of implementing HPV vaccination in Israel. Methods Samples from 84 patients with cervical cancer and 886 patients with CIN3, archived at the Maccabi Institute of Pathology, were screened for HPV. DNA extraction was performed using DNeasy Blood and Tissue Kit/QIAGEN. HPV detection and typing were performed by multiplex polymerase chain reaction with primers E6/E7, using the f-HPV/Genomed kit. Results Of the samples from 84 patients with cervical cancer, 89.3% were positive for HPV. Among these positive samples, HPV-16 was found in 70.7% and HPV-18 was found in 9.3%. Of the samples from 886 patients with CIN3, 85.0% were positive for HPV. Among these positive samples, HPV-16 was found in 73.8% and HPV-18 was found in 1.1%. In the patients with CIN3, the prevalence of HPV genotypes 16 and/or 18 was higher among young women and decreased across age groups. In addition, age, being born in Israel, being born in Europe, and being born in the former Soviet Union were correlated with a low risk of being infected with genotypes 16 and/or 18. Discussion The prevalence of HPV-16 and -18 in patients with cervical cancer and CIN3 in Israel is high. It is expected that the implementation of routine vaccination against these types of HPV will significantly reduce the burden of these diseases in Israel.

Pancreatic cancer ascites xenograft–an expeditious model mirroring advanced therapeutic resistant disease

Pancreatic ductal adenocarcinoma has limited treatment options. There is an urgent need for developing appropriate pre-clinical models recapitulating metastatic disease, the most common clinical scenario at presentation. Ascites accumulation occurs in up to 20–30% of patients with pancreatic cancer; this milieu represents a highly cellular research resource of metastatic peritoneal spread. In this study, we utilized pancreatic ascites/pleural effusion cancer cells to establish patient derived xenografts. Ascites/pleural effusion-patient derived xenografts were established from twelve independent cases. Xenografts were serially passed in nude mice and tissue bio-specimen banking has been established. Histopathology of emergent tumors demonstrates poorly to moderately differentiated, glandular and mucin producing tumors, mirroring morphology of primary pancreatic cancer tumors. Whole genome sequencing of six patient derived xenografts samples demonstrates common mutations and structural variations similar to those reported in primary pancreatic cancer. Xenograft tumors were dissociated to single-cells and in-vitro drug sensitivity screen assays demonstrated chemo-resistance, correlating with patient clinical scenarios, thus serving as a platform for clinically relevant translational research. Therefore, establishment of this novel ascites/pleural effusion patient derived xenograft model, with extensive histopathology and genomic characterization, opens an opportunity for the study of advanced aggressive pancreatic cancer. Characterization of metastatic disease and mechanisms of resistance to therapeutics may lead to the development of novel drug combinations.

Adenosquamous carcinoma arising in a duplication cyst of the gallbladder

A 52-year-old woman, previously healthy was admitted to another hospital due to right upper quadrant abdominal pain, fever and leukocytosis. An ultrasound demonstrated acute cholecystitis and lesion 8 cm. in diameter near the gallbladder. An abdominal CT scan showed the lesion in close proximity to the gallbladder, with fat infiltration. A percutaneous drainage of the lesion under CT guidance yielded a substance which was bloody and purulent in content. The patient improved clinically under antibiotics and was discharged from hospital with a recommendation for elective exploratory laparoscopy.