Imaging features of rare mesenychmal liver tumours: beyond haemangiomas.

Tumours arising from mesenchymal tissue components such as vascular, fibrous and adipose tissue can manifest in the liver. Although histopathology is often necessary for definitive diagnosis, many of these lesions exhibit characteristic imaging features. The radiologist plays an important role in suggesting the diagnosis, which can direct appropriate immunohistochemical staining at histology. The aim of this review is to present clinical and imaging findings of a spectrum of mesenchymal liver tumours such as haemangioma, epithelioid haemangioendothelioma, lipoma, PEComa, angiosarcoma, inflammatory myofibroblastic tumour, solitary fibrous tumour, leiomyoma, leiomyosarcoma, Kaposi sarcoma, mesenchymal hamartoma, undifferentiated embryonal sarcoma, rhabdomyosarcoma and hepatic metastases. Knowledge of the characteristic features of these tumours will aid in guiding the radiologic diagnosis and appropriate patient management

Comparison of virtual to true unenhanced abdominal computed tomography images acquired using rapid kV-switching dual energy imaging.

ObjectiveTo compare "virtual" unenhanced (VUE) computed tomography (CT) images, reconstructed from rapid kVp-switching dual-energy computed tomography (DECT), to "true" unenhanced CT images (TUE), in clinical abdominal imaging. The ability to replace TUE with VUE images would have many clinical and operational advantages.MethodsVUE and TUE images of 60 DECT datasets acquired for standard-of-care CT of pancreatic cancer were retrospectively reviewed and compared, both quantitatively and qualitatively. Comparisons included quantitative evaluation of CT numbers (Hounsfield Units, HU) measured in 8 different tissues, and 6 qualitative image characteristics relevant to abdominal imaging, rated by 3 experienced radiologists. The observed quantitative and qualitative VUE and TUE differences were compared against boundaries of clinically relevant equivalent thresholds to assess their equivalency, using modified paired t-tests and Bayesian hierarchical modeling.ResultsQuantitatively, in tissues containing high concentrations of calcium or iodine, CT numbers measured in VUE images were significantly different from those in TUE images. CT numbers in VUE images were significantly lower than TUE images when calcium was present (e.g. in the spine, 73.1 HU lower, p ConclusionsSignificant differences in VUE images compared to TUE images may limit their application and ability to replace TUE images in diagnostic abdominal CT imaging

Mutation Profiling in Cholangiocarcinoma: Prognostic and Therapeutic Implications

<div><p>Background</p><p>Cholangiocarcinoma (CCA) is clinically heterogeneous; intra and extrahepatic CCA have diverse clinical presentations. Next generation sequencing (NGS) technology may identify the genetic differences between these entities and identify molecular subgroups for targeted therapeutics.</p><p>Methods</p><p>We describe successful NGS-based testing of 75 CCA patients along with the prognostic and therapeutic implications of findings. Mutation profiling was performed using either a) NGS panel of hotspot regions in 46 cancer-related genes using a 318-chip on Ion PGM Sequencer or b) Illumina HiSeq 2000 sequencing platform for 3,769 exons of 236 cancer-related genes plus 47 introns from 19 genes to an average depth of 1000X. Clinical data was abstracted and correlated with clinical outcome. Patients with targetable mutations were referred to appropriate clinical trials.</p><p>Results</p><p>There were significant differences between intrahepatic (n = 55) and extrahepatic CCA (n = 20) in regard to the nature and frequency of the genetic aberrations (GAs). <i>IDH1</i> and DNA repair gene alterations occurred more frequently in intrahepatic CCA, while <i>ERBB2</i> GAs occurred in the extrahepatic group. Commonly occurring GAs in intrahepatic CCA were <i>TP53</i> (35%), <i>KRAS</i> (24%), <i>ARID1A</i> (20%), <i>IDH1</i> (18%), <i>MCL1</i> (16%) and <i>PBRM1</i> (11%). Most frequent GAs in extrahepatic CCA (n = 20) were <i>TP53</i> (45%), <i>KRAS</i> (40%), <i>ERBB2</i> (25%), <i>SMAD4</i> (25%), <i>FBXW7</i> (15%) and <i>CDKN2A</i> (15%). In intrahepatic CCA, <i>KRAS</i>, <i>TP53</i> or <i>MAPK/mTOR</i> GAs were significantly associated with a worse prognosis while <i>FGFR</i> GAs correlated with a relatively indolent disease course. <i>IDH1</i> GAs did not have any prognostic significance. GAs in the chromatin modulating genes, <i>BAP1</i> and <i>PBRM1</i> were associated with bone metastases and worse survival in extrahepatic CCA. Radiologic responses and clinical benefit was noted with EGFR, FGFR, C-met, B-RAF and MEK inhibitors.</p><p>Conclusion</p><p>There are significant genetic differences between intra and extrahepatic CCA. NGS can potentially identify disease subsets with distinct prognostic and therapeutic implications.</p></div

Ingenuity Pathway Analysis indicates canonical signaling pathways involved in CCA.

<p>Homology noted with more commonly occurring solid tumors including melanoma and glioblastoma.</p

Univariate Analysis of Survival – Extrahepatic CCA.

<p>Univariate Analysis of Survival – Extrahepatic CCA.</p

Genetic differences identified between Intrahepatic and Extrahepatic CCA

<p>Genetic differences identified between Intrahepatic and Extrahepatic CCA</p

A 68 year old female with <i>KRAS wt</i> intrahepatic CCA.

<p>Axial (A) fused PET-CT and (B) unenhanced CT images demonstrate multiple confluent FDG avid liver metastases. After 3 months of erlotinib therapy, (C) axial fused PET-CT and (D) unenhanced CT images show decreased FDG avidity and slightly decreased size of metastases.</p

Relationship of Overall Survival with presence of <i>KRAS</i> mutation in cases of Intrahepatic CCA.

<p>Relationship of Overall Survival with presence of <i>KRAS</i> mutation in cases of Intrahepatic CCA.</p

A 69 year old female with KRAS mutated CCA metastatic to the ovaries.

<p>(A) Coronal contrast-enhanced CT image demonstrates a 15.4×12.6×12.2 cm (transverse × craniocaudal × AP) pelvic mass. (B) After two cycles of trametinib + pazopanib therapy, the pelvic mass is slightly decreased to 13.5×11.3×13.4 cm.</p