Elif Aktas

Diagnostic value of diffusion-weighted magnetic resonance imaging: differentiation of benign and malignant lymph nodes in different regions of the body ☆

INTRODUCTION To evaluate the value of diffusion-weighted magnetic resonance imaging compared with conventional magnetic resonance imaging (C-MRI) for the differentiation of benign from malignant lymph nodes in different regions of the body. PATIENTS AND METHODS A total of 31 patients ranging in age from 18 to 75 years (mean age: 53 years) were included in this study. The patients were examined using a 1.5-T magnetic resonance imaging system with coils chosen according to lymph node locations. Diffusion-weighted images were obtained using the single-shot echo planar sequence and had b values of 50, 500, and 1000 s/mm(2.) The apparent diffusion coefficient (ADC) values were measured from ADC maps. The correlation between the pathological diagnoses and mean ADC values in the benign and malignant lymph node groups were compared using the Mann-Whitney U-test with Bonferroni correction. Receiver operating characteristic (ROC) analysis was performed to evaluate the diagnostic performance of the method. RESULTS The mean ADC value for benign lymph nodes was 0.97×10(-3) mm(2)/s (range: 0.6-1.2×10(-3) mm(2)/s), and the mean ADC value for malignant lymph nodes was 0.76×10(-3) mm(2)/s (range: 0.3-1.2×10(-3) mm(2)/s) (P<.001). In ROC analysis, the cut-off ADC value for malignant versus benign lymph node differentiation was 0.8×10(-3) mm(2)/s. Using an ADC value of 0.8×10(-3) mm(2)/s, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of the method for differentiating between benign and malignant lymph nodes were 76.4%, 85.7%, 86.6%, 75%, and 80.6%, respectively. The sensitivity, specificity, PPV, NPV, and accuracy of C-MRI were 88.2%, 78.5%, 83.3, 84.6%, and 83.8%, respectively. The sensitivity, specificity, PPV, NPV, and accuracy of C-MRI findings suspicious for malignancy combined with the ADC values were 76.4%, 64.2%, 100%, 81.8%, and 91.6%, respectively. CONCLUSIONS C-MRI alone remained superior to diffusion-weighted imaging (DWI) and combination C-MRI and DWI for differentiating malignant from benign lymph nodes; however, DWI and ADC calculation may play a role in lymph node characterization.

Ulcerative colitis triggered by pegylated interferon alone therapy for chronic hepatitis C

To the Editor: Interferon (IFN) alpha, a therapy not only for chronic viral hepatitis but also for multiple sclerosis, some solid tumors, and myeloproliferative disorders, was described as a trigger of some autoimmune disorders. Since ulcerative colitis (UC) is a chronic inflammatory disease, the role of IFNs on the treatment of UC was investigated. Here we describe a UC patient with a diagnosis of chronic hepatitis C (HCV) after IFN therapy. A 34-year-old woman was admitted to the hospital due to bloody diarrhea. She had a history of a routine hemodialysis program for 14 years. Bloody diarrhea 5 to 7 times a day and abdominal cramps relieved by defecation were started after three doses of weekly pegylated IFN use due to the chronic HCV. Clinical examination was unremarkable except for high bowel sounds (no sign of abdominal tenderness or fever). Routine blood tests were: aspartate aminotransferase (AST) 56 (U/L) (0–40), alanine aminotransferase (ALT) 45 (U/L) (0–41), alkalene phosphatase (ALP) 247 (U/L) (0–270), gammaglutamyl transpherase (GGT) 45 (U/L) (0–55), total protein 7.9 g/L (6.4–8.3), albumin 3.7 g/dL (3.8–5.1), and total bilirubin (T Bil) 0.6 mg/dL (0–1), creatinine 0.8 mg/dL (0.9–1.3), hemoglobin 13.2 g/dL, leukocytes 7.6 10/mL, platelet 176 10/ mL, sedimentation rate 45 mm/hour, and C-reactive protein 3 mg/dL. The stool examination for ova, parasites, cultures, and Clostridium difficile toxin were all negative. In her history she had no surgery or any medication use. She denied taking any herbal drugs, alcohol abuse, or risk factors for sexually transmitted diseases. Colonoscopic examination showed diffuse hyperemia and edematous area with exudates, ulcerations, and fragility starting from the descending colon to the anorectal area. The biopsies from the mucosa described above revealed UC. Pegylated IFN was discontinued and mesalazine was prescribed at a dose of 2 g per day. The symptoms were relieved in the following days and control colonoscopy revealed mucosa healing by the third month of therapy. A recent meta-analysis revealed that IFN therapy in UC remission is not beneficial. However, physicians face problems in patients with both UC and chronic HCV. In spite of both remission and induction of UC with the use of IFN being reported before, Bargiggia et al treated chronic active HCV patients with inactive, or mildly active UC, and none of them developed a UC relapse under IFN therapy, 12 months thereafter, in contrast to the cases mentioned above. The case reports of an exacerbation of UC attributed to IFN were under both standard IFN alone, and PEG-IFNþ ribavirin. Also, the date of relapse and region of active colitis were all different from each other (varying from 1 day after initiation of therapy to 7 days after stopping, and from rectum to total colonic disease). Most of the patients became well after the discontinuation of IFN and starting of mesalazine alone, or mesalazine with short-term steroid. In conclusion, IFN therapy without ribavirin can be a predisposing factor for UC exacerbation, especially in therapy-naı̈ve patients.

Erdheim-Chester disease in thoracic spine: a rare case of compression fracture

A55-year-old man with back pain for about 2 months was admitted to an orthopedics department. A plain radiological examination of the thoracic spine revealed a collapse of the T2 vertebra. Preoperative magnetic resonance imaging and a computed tomography scan showed a collapse of the T2 vertebra body (Figs. 1 and 2). The lesion involving theT2 vertebra body showed heterogenous enhancement inT1-weightedmagnetic resonance images after administration of gadolinium (Fig. 2). An open bone biopsy of the T2 vertebra body was performed. Based on the histopathologic and radiological findings, the patient was diagnosed with Erdheim-Chester disease (ECD) with involvement of bone marrow (Fig. 3). Erdheim-Chester disease is an infrequent, non-Langerhans cell histiocytosis of unknown etiology that typically affects the lower extremity of long bones, causing osteosclerosis. Isolated axial skeleton involvement of ECD is extremely rare. Imaging features of ECD involvement of vertebra are not specific, so pathologic confirmation is needed. As in our case, the possibility of ECD in patients with compression fracture can be considered [1,2]. References

The Advantages and Limitations of Ultrasound Elastography in Diagnosis of Thyroid Carcinoma

Thyroid nodules have high prevalence in the general population. Only minorities of thyroid nodules are malignant; nevertheless, still biopsies are performed in differen‐ tial diagnosis of malignant and benign thyroid nodules. Conventional ultrasound is widely used in diagnosis and characterization of thyroid nodules. There are several suspicious ultrasound features that predict thyroid cancer, such as solid consistence, marked hypoechogenicity, taller-than-wide shape, irregular or microlobulated or spiculated margins, no peripheral hypoechoic halo, and microor macrocalcifications. However, none of these signs have high sensitivity or specificity nor high degree of confidence for diagnosis or exclusion of thyroid carcinoma. Ultrasound elastography, recently developed, promising, noninvasive technique that evaluates tissue stiffness, has become one of the main focuses in thyroid imaging. There are two ultrasound elastography methods: strain ultrasound elastography (also known as real-time elastography or qualitative elastography) and shear wave elastography (quantitative elastography and acoustic radiation force impulse imaging). The purpose of this chapter is to present the principles of thyroid application, advantages, and limitations of both ultrasound elastography techniques.

Magnetic Resonance Imaging Findings in Childhood Period Nasopharynx Cancer

Summary Background Nasopharyngeal carcinoma is a rarely seen tumor in childhood. It is mostly detected late as the clinical features are similar to other childhood tumors which affect the nasopharynx and adenoidal hypertrophy. Therefore, the radiological features of childhood tumors of the nasopharynx must be well known. The aim of this study was to investigate the contribution of MR imaging features of childhood nasopharynx cancer. Material/Methods The study included 10 nasopharyngeal carcinoma patients under the age of 18 years who presented at hospital between February 2008 and March 2014 and who had tissue diagnosis and MRI of the nasopharynx region. The MRI scans were evaluated by two radiologists. Loco-regional spread, asymmetry, signal intensity of the tumors, and lymph nodes were evaluated. Results In all the patients there was a mass which narrowed the nasopharynx. In all cases, unilateral mastoid opacification was observed. In 9 cases (90%), parapharyngeal extension was found. In 8 cases (80%), the mass showed an extension into the nasal cavity or oropharynx. In 5 cases (50%), there was an involvement of the skull base. In 3 patients (30%), an extension to the masticator space and pterygopalatine fossa was found. There were enlarged cervical lymph nodes bilaterally in 10 cases (100%). In 4 cases (40%), a lateral retropharyngeal lymph node was detected. Conclusions Childhood nasopharyngeal cancers are often diagnosed at an advanced stage. MR imaging can be helpful in diagnosis and differential diagnosis of childhood nasopharynx cancer from other diseases of the nasopharynx.

Peritoneal mezotelyoma: Bilgisayarlı tomografi ve magnetik rezonans görüntüleme bulguları ve ayırıcı tanıya katkısı

Objective: In this article, we review radiologic findings of malignant peritoneal mesothelioma with our patient archives. We also want to determine importance of radiologic findings about differential diagnosis of malignant peritoneal mesothelioma. Materials and methods: We scanned our patient archive of mesothelioma between 2008 and 2012 years. We included 15 patients with peritoneal mesothelioma who underwent computerized tomography (CT) or magnetic resonance imaging (MRI) at their initial diagnosis. Results: We found peritoneal irregularity and nodular thickening in 11 patients (73.3%), diffuse peritoneal thickening (omental cake) in 5 patients (33.3%), ascites in 9 patients (60%), extension of adjunct tissue and hepatic metastases in only one patient (6.6%). Conclusion: The diagnosis of peritoenal malignant mesothelioma may be difficult with only clinical findings. CT and MRI are helpful to diagnose and show spread of disease, but tissue biopsy is required for the definitive diag nosis.

Radiologic Evaluation of Malignant Pleural and Peritoneal Mesothelioma

Mesothelioma usually presents in the fifth to seventh decades, and 70-80 % of cases occur in men (Moore et al., 2008). Malignant pleural mesothelioma (MPM) is the most widely form of mesothelioma. Patients frequently present with dyspnea, chest pain, cough, and weight loss (Moore et al., 2008, Wang et al., 2004). Although most of the mesotheliomas cover the pleural surface, approximately 35% arise only from peritoneum. Patients with malignant peritoneal mesothelioma may present with abdominal pain, distention, anorexia, and weight loss (Park et al., 2008).