Evaluation of the Relationships Between Computed Tomography Features, Pathological Findings, and Prognostic Risk Assessment in Gastrointestinal Stromal Tumors.

OBJECTIVES: The aim of this study was to correlate computed tomography (CT) findings with pathology in gastrointestinal stromal tumors (GISTs). METHODS: A retrospective evaluation of CT images of 44 patients with GISTs was performed. Computed tomography findings analyzed were location, size, margins, degree and pattern of contrast enhancement, angiogenesis, necrosis, signs of invasion, peritoneal effusion, peritoneal implants, surface ulceration, and calcifications.Associations between CT features and mitotic rate, Miettinen classes of risk, lesions size, and among CT features were investigated. χ Test and Fisher test were performed. RESULTS: Mitotic rate was associated with margins (P = 0.016) and with adjacent organ invasion (P = 0.043). Pattern of contrast enhancement (P = 0.002), angiogenesis (P = 0.006), necrosis (P = 0.006), invasion of adjacent organs (P = 0.011), and margins (P = 0.006) were associated with classes of risk. Several associations (P < 0.05) between lesion size and CT features and among all the investigated CT features were found. CONCLUSIONS: Computed tomography features could reflect GIST biology being associated with the mitotic rate and with classes of risk.

Gadoxetic acid-enhanced MRI for hepatocellular carcinoma and hypointense nodule observed in the hepatobiliary phase.

PURPOSE: The aim of our study was to evaluate the diagnostic accuracy of gadoxetic acid-enhanced magnetic resonance (MR) imaging both in the detection of hepatocellular carcinoma (HCC) and precancerous lesions and in the assessment of their evolution. MATERIALS AND METHODS: A retrospective study was undertaken on 56 patients with chronic liver disease and suspected liver lesions. We evaluated the number, size and signal intensity of the nodules on dynamic and hepatobiliary MR images. Follow-up studies were carried out every 3 months. Statistical analysis was performed using the Fisher's exact test. RESULTS: A total of 120 nodules were identified in 41 patients. Of these, 92/120 nodules (76.6%; mean diameter 18.4 mm) showed the typical HCC vascular pattern: 90/92 nodules appeared hypointense and 2/92 were hyperintense on hepatobiliary phase images. An additional 28/120 hypointense, nonhypervascular nodules (23.3%; mean diameter 11 mm) were detected on hepatobiliary phase images, 15 of which showed hypointensity also on the equilibrium phase images. During the 3- to 12-month follow-up, 14/28 nodules (mean diameter 13.3 mm) developed the typical vascular pattern of HCC. CONCLUSIONS: Gadoxetic acid-enhanced MR imaging is useful for detecting HCC as well as hypovascular nodules with potential progression to HCC. Lesions measuring more than 10 mm in diameter are at higher risk of developing into HCC (p = 0.0128).

Comparison of diffusion-weighted imaging and gadoxetic acid-enhanced MR images in the evaluation of hepatocellular carcinoma and hypovascular hepatocellular nodules.

PURPOSE: To compare diffusion-weighted imaging (DWI) and gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) magnetic resonance imaging (MRI) in the evaluation of hepatocellular carcinoma (HCC) and nodules at high risk of HCC transformation. MATERIALS AND METHODS: We evaluated nodules' size, vascular pattern, and signal intensity on hepatobiliary phase images and on DWI of 105 nodules (41 cirrhotic patients). RESULTS: A total of 35/66 HCCs identified on Gd-EOB-DTPA MRI showed hyperintensity on DWI. A total of 25/39 nodules (hypovascular and hypointense nodule on hepatobiliary phase images) progressed to HCC (higher risk for nodules ≥10mm in size and hyperintense on DWI, P<.05). CONCLUSION: Gd-EOB-DTPA MRI demonstrated a significant role in the identification of nodule at higher risk of HCC transformation, and hyperintensity on DWI was associated with progression to HCC.

Magnetic resonance cholangiopancreatography with secretin stimulation in the diagnosis of intraductal papillary mucinous neoplasm: a paradigmatic case report.

Context. One of the characteristic findings of intraductal papillary mucinous neoplasms (IPMN) is the presence of a direct communication between the lesion and the ductal pancreatic system and when magnetic resonance cholangiopancreatography (MRCP) shows uncertain findings, it is useful to perform a MRCP after secretin stimulation (MRCP-S) which provides a better visualization of the ductal system. Case Report. We present a case of 51-year-old man in whom, during a CT follow-up for a renal tumour, was found a cystic lesion of the pancreas. To better evaluate the lesion and its suspected communication with the pancreatic system, MR with gadolinium and MRCP and MRCP-S were performed. With the MRCP and MRI it was not possible to identify a clear communication between the cystic lesion and the ductal system. MRCP-S showed an increase in signal intensity of the lesion and its communication with the ductal system, allowing us to classify the cystic lesion as a main duct in intraductal papillary mucinous neoplasm. The patient underwent a surgical duodenal pancreatectomy. The histological result of the specimen confirmed the diagnosis of adenocarcinoma IPMN. Conclusion. In this case MRCP-S has allowed a clearer identification of the cystic lesion allowing a correct diagnosis and treatment.

Simultaneous intraductal papillary neoplasms of the bile duct and pancreas treated with chemoradiotherapy.

Some authors have suggested that intraductal papillary mucinous neoplasms of the bile duct (IPMN-B) could be the the biliary counterpart of IPMN of the pancreas (IPMN-P) since they share several clinical-pathological features. These include prominent intraductal papillary proliferation pattern, a gastrointestinal phenotype, frequent mucin hyper-secretion and progression to mucinous carcinoma. To date there are just four reported cases of patients with synchronous IPMN-B and IPMN-P all of which were treated surgically. We hereby report the case of a 76-year-old woman who was incidentally diagnosed with both an asymptomatic 3 cm bulky fluid lesion obstructing the bile duct lumen, diagnosed as a malignant IPMN-B, and synchronous multiple pancreatic cystic lesions (10-13 mm) communicating with an irregular Wirsung, diagnosed as branch duct IPMN-P. Since surgery was ruled-out because of the patient's age and preferences, she underwent a conservative management regimen comprising both chemotherapy and radiotherapy. This was effective in decreasing the mass size and in resolving subsequent jaundice. This is also the first reported case of IPMN-B successfully treated with chemoradiotherapy. Clinicians should consider medical treatment as an option in this clinical scenario, in patients who may be unfit for surgery.