Imaging features of solid pseudopapillary tumor of the pancreas on multi-detector row computed tomography

AIM： To retrospectively analyze the imaging features of solid-pseudopapillary tumors （SPTs） of the pancreas on multi-detector row computed tomography （MDCT） and define the imaging findings suggestive of malignant potential. METHODS： A total of 24 consecutive cases with surgically and pathologically confirmed SPTs of the pancreas underwent preoperative abdominal MDCT studies in our hospital. All axial CT images, CT angiographic images, and coronally and sagittally reformed images were obtained. The images were retrospectively reviewed at interactive picture archiving and communication system workstations. RESULTS： Of the 24 cases of SPTs, 11 cases （45.8%） occurred in the pancreatic head and seven （29.1%） in the tail. Eighteen were pathologically diagnosed as benign and six as malignant. MDCT diagnosis of SPTs was well correlated with the surgical and pathological results （Kappa = 0.6, P 〈 0.05）. The size of SPTs ranged from 3 to 15 cm （mean, 5.8 cm）. When the size of the tumor was greater than 6 cm （including 6 cm）, the possibilities of vascular （8 vs 1） and capsular invasion （9 vs 0） increased significantly （P 〈 0.05）.Two pathologically benign cases with vascular invasion and disrupted capsule on MDCT presented with local recurrence and hepatic metastases during follow-up about 1 year after the resection of the primary tumors. CONCLUSION： Vascular and capsular invasion with superimposed spread into the adjacent pancreatic parenchyrna and nearby structures in SPTs of the pancreas can be accurately revealed by MDCT preoperatively. These imaging findings are predictive of the malignant potential associated with the aggressive behavior of the tumor, even in the pathologically benign cases.

SOLID PSEUDOPAPILLARY TUMOR OF THE PANCREAS:CLINICAL AND COMPUTED TOMOGRAPHIC FINDINGS WITH PATHOLOGIC CORRELATION IN 21 CASES

Objective To correlate the clinical and imaging features of the solid pseudopapillary tumor (SPPT) of the pancreas with the pathologic diagnosis. Methods The computed tomographic findings in 21 patients (18 women and 3 men) with pathologically proven solid pseudopapillary tumor of the pancreas were reviewed retrospectively. Two radiologists reviewed images for location, size and morphology, capsule and margin, density, enhancement pattern, calcification, dilatation of pancreatic duct, lymphadenopathy, vascular invasion, distant metastasis, and recurrence. Results On CT, the lesion presented as solitary, round (28.57%), oval (57.14%), or lobulated (14.28%) mass in pancreatic head (47.62%) with complete capsule (85.71%). Lesions smaller than 4cm in maximum diameter (47.62%) presented as predominantly solid mass whereas lesions greater than 4cm in diameter (52.28%) presented as heterogenous mass. On contrast administration, the viable solid portion of the tumor showed mild peripheral enhancement in arterial phase [enhancement degree<20Hounsfield unit (HU)] with progressive fill in during the portal and hepatic parenchyma phase (enhancement degree 20-40HU). Eighteen lesions (85.7%) had complete capsule. Two lesions (9.5%) had areas of high density (>60HU) on plain CT which due to hemorrhage. Dilatation of the pancreatic duct was rare (25%), and distant metastasis, regional lymphadenopathy, and tumor recurrence were absent. Nine patients (42.85%) had an abdominal CT follow-up for 24.55months (range, 2-60months) post-surgery without recurrence or distant metastasis. Conclusion Solid pseudopapillary tumor of the pancreas usually occurs in young females in the pancreatic head or tail. On CT, they manifest as moderate vascular mixed tumor, progressive enhancement of the viable solid portion, distinct tumor margin with capsule formation, and absence of regional lymphadenopathy.

Pancreatic neuroendocrine tumor detected by technetium-99m methoxy-2-isobutylisonitrile single photon emission computed tomography/computed tomography:A case report

BACKGROUND Pancreatic neuroendocrine tumors(NETs)account for about 1%–2%of pancreatic tumors and about 8%of all NETs.Computed tomography(CT),magnetic resonance imaging,and endoscopic ultrasound are common imaging modalities for the diagnosis of pancreatic NETs.Furthermore,somatostatin receptor imaging is of great value for diagnosing pancreatic NETs.Herein,we report the efficacy of technetium-99m methoxy-2-isobutylisonitrile(99mTc-MIBI)single photon emission CT(SPECT)/CT for detecting pancreatic NETs.CASE SUMMARY A 57-year-old woman presented to our hospital with a 1-d history of persistent upper abdominal distending pain.The distending pain in the upper abdomen was aggravated after eating,with nausea and retching.Routine blood test results showed a high neutrophil percentage,low leukomonocyte and monocyte percentages,and low leukomonocyte and eosinophil counts.Amylase,liver and kidney function,and tumor markers alpha-fetoprotein,carcinoembryonic antigen,and cancer antigen(CA)125,CA72-4,CA19-9,and CA153 were normal.Abdominal CT showed a mass,with multiple calcifications between the pancreas and the spleen.The boundary between the mass and the pancreas and spleen was poorly defined.Contrast-enhanced CT revealed that the upper abdominal mass was unevenly and gradually enhanced.99mTc-MIBI SPECT/CT revealed that a focal radioactive concentration,with mild radioactive concentration extending into the upper abdominal mass,was present at the pancreatic body and tail.The 99mTc-MIBI SPECT/CT manifestations were consistent with the final pathological diagnosis of pancreatic NET.CONCLUSION 99mTc-MIBI SPECT/CT appears to be a valuable tool for detecting pancreatic NETs.

A correlation of computed tomography perfusion and histopathology in tumor edges of hepatocellular carcinoma

BACKGROUND： The peripheral morphologic characteristics of hepatocellular carcinoma （HCC） reflect tumor growth patterns. Computed tomography （CT） perfusion is a new method to analyze hemodynamic changes in tissues. We assessed the relationship between CT perfusion and histopathologic findings in the periphery of HCC lesions. METHODS： Non-contrast CT, enhanced dual-phase CT, and CT perfusion were performed on 77 subjects （47 patients and 30 controls）. Based on the imaging findings of enhanced dual- phase CT, the tumor edges were classified into three types： type Ⅰ （sharp）; type Ⅱ （blurry）; and type Ⅲ （mixed）. The CT perfusion parameters included hepatic blood flow, hepatic arterial fraction, hepatic arterial perfusion, and hepatic portal perfusion. The tissue sections from resected specimens were subjected to routine hematoxylin and eosin staining and immunohistochemical staining for CD34. The correlations between microvessel density （MVD） and the CT perfusion parameters were analyzed using Pearson＇s product-moment correlation coefficient. Changes in the perfusion parameters in tumor edges of different tumor types were evaluated. RESULTS： Type Ⅰ （sharp）： the pathologic findings showed fibrous connective tissue capsules in the tumor edges, and an MVD 〈30/ram2. Type Ⅱ （blurry）： the histology showed that the edges were clear with no capsules and an MVD 〉30/ram2. Type Ⅲ （mixed）： the pathology was similar to that of types I and II, and an MVD 〉30/mm~. Hepatic blood flow, hepatic arterial fraction, hepatic arterial perfusion, and hepatic portal perfusion were significantly increased in the tumor edges of HCC patients compared to those of the controls （P〈0.05）. The correlation between CT perfusion parameters and MVD was higher in blurry tumor edges of type II than in those of types Ⅰ or Ⅲ. CONCLUSION： CT perfusion imaging of tumor edges may be helpful in revealing histopathological features, and indirectly reflect angiogenic changes of HCCs.

SPECTRUM OF FUNCTIONING ISLET CELL TUMOR ON MULTISLICE COMPUTED TOMOGRAPHY:EXPERIENCE ON 70 PATIENTS

Objective To review experience in preoperative detection of islet cell tumors using multislice computed tomography （MSCT） and summarize various imaging features of functioning islet cell tumors on enhanced MSCT. Methods Seventy patients with clinical or pathological diagnosis of functioning pancreatic islet cell tumor between October 2003 and February 2007 were included in this retrospective study. Seventy-four enhanced MSCT scans in these patients were identified. All MSCT scans were interpreted by two experienced radiologists by consensus interpretation. Surgery and pathology reports were used to confirm the diagnosis, localization, and size of tumors. Results Totally, 73 functioning islet cell tumors including 65 benign insulinomas, 2 benign glucagonomas, 3 malignant insulinomas, and 3 malignant glucagonomas were pathologically diagnosed. Tumors in only two cases were not found by MSCT. In 67 benign lesions, 32 showed typical enhancement style, 21 showed prolonged enhancement in portal venous phase, 4 showed delayed enhancement, 4 had iso-dense enhancement with normal pancreatic parenchyma, 2 had no enhancement at all in arterial phase and portal venous phase, and 4 had inhomogeneous enhancement with necrosis or cyst-formation. Patchy or spotty calcifications were found in 3 of the 67 tumors. In 6 malignant islet cell tumors, vessel invasion （2/6） and bowel invasion （1/6） were seen. Different enhancement patterns were shown. All hepatic metastases showed hyper-enhancement during their arterial phase. Conelttsions Pancreatic islet cell tumor may display a wide spectrum of presentations in MSCT. Tumors with unusual appearances often present as diagnostic challenges. Non-contrast and post-contrast multiphase scans are recommended for the localization of functioning islet cell tumors.

Deep learning model combined with computed tomography features to preoperatively predicting the risk stratification of gastrointestinal stromal tumors

BACKGROUND Gastrointestinal stromal tumors(GIST)are prevalent neoplasm originating from the gastrointestinal mesenchyme.Approximately 50%of GIST patients experience tumor recurrence within 5 years.Thus,there is a pressing need to accurately evaluate risk stratification preoperatively.AIM To assess the application of a deep learning model(DLM)combined with computed tomography features for predicting risk stratification of GISTs.METHODS Preoperative contrast-enhanced computed tomography(CECT)images of 551 GIST patients were retrospectively analyzed.All image features were independently analyzed by two radiologists.Quantitative parameters were statistically analyzed to identify significant predictors of high-risk malignancy.Patients were randomly assigned to the training(n=386)and validation cohorts(n=165).A DLM and a combined DLM were established for predicting the GIST risk stratification using convolutional neural network and subsequently evaluated in the validation cohort.RESULTS Among the analyzed CECT image features,tumor size,ulceration,and enlarged feeding vessels were identified as significant risk predictors(P<0.05).In DLM,the overall area under the receiver operating characteristic curve(AUROC)was 0.88,with the accuracy(ACC)and AUROCs for each stratification being 87%and 0.96 for low-risk,79%and 0.74 for intermediate-risk,and 84%and 0.90 for high-risk,respectively.The overall ACC and AUROC were 84%and 0.94 in the combined model.The ACC and AUROCs for each risk stratification were 92%and 0.97 for low-risk,87%and 0.83 for intermediate-risk,and 90%and 0.96 for high-risk,respectively.Differences in AUROCs for each risk stratification between the two models were significant(P<0.05).CONCLUSION A combined DLM with satisfactory performance for preoperatively predicting GIST stratifications was developed using routine computed tomography data,demonstrating superiority compared to DLM.

A case of solid pseudopapillary tumor of the pancreas

We present ultrasound, computed tomography and magnetic resonance imaging findings in a case with pancreatic solid pseudopapillary tumor and their correlations with histopathology. Ultrasound revealed a hypoechogenic mass, and computed tomography revealed a hypodense mass at the pancreatic head minimally enhanced after intravenous contrast agent administration. Magnetic resonance imaging showed a hypointense mass on unenhanced Tl-weighted images including a hyperintense focus representing the hemorrhage. The lesion was hyperintense on T2- weighted images. On the postcontrast images the lesion showed peripheral thin contrast enhancement in arterial phase and enhanced slightly diffusely in venous and equilibrium phases. The patient underwent elective resection of the mass and pancreatoduodenectomy with jejunostomy tube placement. A final diagnosis of solid pseudopapillary tumor was made histoPathologically. Solid pseudopapillary tumor is a rare pancreatic tumor. It is important to make the diagnosis preoperatively because with an adequate surgical resection the prognosis is good. A multimodalitary approach, especially magnetic resonance imaging can suggest the diagnosis without the need for biopsy.

Solid-pseudopapillary tumor of the pancreas:CT and MRI features of 3 cases

BACKGROUND: Solid-pseudopapillary tumor of the pancreas is a rather rare but low-grade malignant tumor with good prognosis after surgical excision. METHODS: In 3 patients with solid-pseudopapillary tumor of the pancreas which were proved pathologically, the imaging features ( CT in all and MRI in one patient) of the tumor were analyzed. RESULTS: In the 3 female patients under 35-year-old who presented no jaundice, CT revealed that huge solid-cystic masses of the pancreatic head with calcification in one and slight dilation of the pancreatic duct in another, but without dilation of the bile duct system in all. MRI demonstrated mixed signal intensity on T1WI and T2WI of the mass in one patient. CT and MRI revealed obvious enhancement of the cystic wall and solid part of the masses. CONCLUSIONS: CT and MRI findings of solid-pseudopapillary tumor of the pancreas are characteristic, and the diagnosis can be made preoperatively with the combination of clinical features.

Sclerosing epithelioid fibrosarcoma of the pancreas:A case report

BACKGROUND A sclerosing epithelioid fibrosarcoma(SEF)is a rare malignant fibroblastic soft tissue tumor that rarely occurs in intra-abdominal organs.A case of a SEF in the pancreatic head is reported herein,including its clinical manifestations,preoperative imaging features,gross specimen and pathological findings.CASE SUMMARY A 33-year-old male patient was admitted to Peking Union Medical College Hospital in December 2023 due to a one-year history of intermittent upper abdominal pain and the discovery of a pancreatic mass.The patient underwent an enhanced computed tomography scan of the abdomen,which revealed a welldefined,round mass with clear borders and calcifications in the pancreatic head.The mass exhibited progressive,uneven mild enhancement,measuring approximately 6.6 cm×6.3 cm.The patient underwent laparoscopic pylorus-preserving pancreaticoduodenectomy.Postoperative pathological examination revealed that the lesion was consistent with a SEF.At the 3-month postoperative follow-up,the patient did not report any short-term complications,and there were no signs of tumor recurrence.CONCLUSION SEFs are rare malignant fibrous soft tissue tumors.SEFs rarely develop in the pancreas,and its preoperative diagnosis depends on imaging findings,with confirmation depending on pathological examination and immunohistochemistry.Currently,only four cases of pancreatic SEF have been reported in studies written in English.This case is the first reported case of a pancreatic SEF by a clinical physician.

Increased risk of second malignancy in pancreatic intraductal papillary mucinous tumors: Review of the literature

AIM: To analyze the available evidence about the risk of extrapancreatic malignancies and pancreatic ductal adenocarcinoma associated to pancreatic intraductal papillary mucinous tumors(IPMNs).METHODS: A systematic search of literature was undertaken using MEDLINE, EMBASE, Cochrane and Web-of-Science libraries. No limitations for year of publication were considered; preference was given to English papers. All references in selected articles were further screened for additional publications. Both clinical series and Literature reviews were selected. For all eligible studies, a standard data extraction form was filled in and the following data were extracted: study design, number of patients, prevalence of pancreatic cancer and extrapancreatic malignancies in IPMN patients and control groups, if available.RESULTS: A total of 805 abstracts were selected and read; 25 articles were considered pertinent and 17 were chosen for the present systematic review. Eleven monocentric series, 1 multicentric series, 1 casecontrol study, 1 population-based study and 3 case report were included. A total of 2881 patients were globally analyzed as study group, and the incidence of pancreatic cancer and/or extrapancreatic malignancies ranged from 5% to 52%, with a mean of 28.71%.When a control group was analyzed(6 papers), the same incidence was as low as 9.4%.CONCLUSION: The available Literature is unanimous in claiming IPMNs to be strongly associated with pancreatic and extrapancreatic malignancies. The consequences in IPMNs management are herein discussed.

MSCT and MRCP features of intraductal papillary mucinous tumor of the pancreas

Objective:To study the multi-slice CT(MSCT) and magnetic resonance cholangio-pancreatography(MRCP) features of intraductal papillary mucinous tumor(IPMT) of the pancreas.Methods:The clinical information,laboratory val-ues,imaging features and pathological findings of 8 cases were reviewed.Results:There were 6 males and 2 females with average 71.3 years old in this series.These lesions involved pancreatic branch ducts or main duct.Among them,2 cases were involved in the pancreatic uncinate process,1 case in the pancreatic head,1 in the pancreatic body,2 in the pancreatic tail and 2 cases involved multiple pancreatic duct.The common complaint was chronic upper abdominal pain.The imaging features included cystic lesion and it's association with the dilated pancreatic main duct,and bulging of the duodenal papilla.Mucin plug,septa or mural nodule were found in these cystic lesions.5 cases were confirmed with endoscopic retrograde cholangio-pancreatography(ERCP).3 cases had undergone surgery.Pathological findings of the 3 cases were adenoma,adenocarcinoma and borderline tumor,respectively.Conclusion:The MSCT and MRCP features of IPMT are somewhat characteristic,and the correct diagnosis can be made with the combination of clinical features.Diameter of branch duct ≥ 3 cm with multiple or large mural nodules,or severe dilated main duct indicates the probability of malignant IPMT.

Imaging of the Extra-axial Tumors and Tumor-like Lesions Involving both Middle and Posterior Cranial Fossae: Classification and Diagnosis

Objective: To study the imaging features of extra-axial tumors and tumor-likelesions involving both middle and posterior cranial fossae and to make a classification. Methods:Sixty cases of pathologically confirmed extra-axil tumors and tumor-like lesions involving bothmiddle and posterior cranial fossae were analyzed. They were divided into central and lateral types,the latter of which were subdivided into three types: middle cranial fossae type, posterior cranialfossae type and the over-riding type. The constitution and imaging features of each type wereanalyzed. Results: There were 12 cases of central type, including chordoma (n=5), pituitary adenoma(n=3), nasopharyngeal carcinoma (n=2), craniopharyn-gioma (n=1) and meningioma (n=l). 48 cases oflateral type including trigeminal nerve tumors (n=14), meningioma (n=12), epidermoid cyst (n=11),dural cavernous hemangioma (n=4), dermoid cyst (n=2), metastasis (n=2), hemangiopericytoma (n=1),paraganglioma of glonius jugular (n=1) and nasopharyngeal carcinoma (n=1). Each type of the lesionshad its own shape features, some of which were characteristic for some specific tumors. Most of thetumors and tumor-like lesions could be qualitatively diagnosed according to their imagingcharacteristics and the extent of the lesions could be defined definitely. Conclusion: It is helpfulto categorize extra-axial tumors and tumor-like lesions involving both middle and posterior cranialfossae according to their location for qualitative diagnosis and description of the extent of theselesions. It is of great clinical value in providing more precise and thorough imaging informationfor planning therapeutic methods and route of operation.

Primary Malignant Renal Tumors in Infancy and Childhood: CT Appearances

Objective： To investigate the imaging manifestation of primary malignant renal tumor with CT. Methods： Forty-three cases of surgically and pathologically confirmed primary malignant renal tumor were retrospectively reviewed. Un-contrast and contrast CT was performed in all 43 patients in which 15 patients received MRI examination. Results： The residual normal renal tissue of 29 cases out of 34 cases of Wilms＇ tumor was enhanced and manifested ＂crescent sign＂ or ＂ring sign＂. Four cases of malignant rabdoid tumor （RTK） manifested as large mass with notable necrosis and subcapsular fluid collection; Two cases of clear cell sarcoma （CCS） showed metastases to the skull which could indicate the diagnosis; Renal cell carcinoma （RCC） （n=3） showed calcification in 1 case. Conclusion： CT can precisely delineate the location, size, extent of involvement, imaging characteristics and metastases of renal tumor, which can provide information necessary to the clinical staging, therapy planning and prognosis of the tumors.

Unusual gastric tumors and tumor-like lesions: Radiological with pathological correlation and literature review

Although gastric tumors have overlapping radiologic appearances, some unusual tumors may present specific imaging features. Using multidetector computed tomography(MDCT), with water as a negative oral contrast agent and intravenous contrast medium, can provide critical information for the diagnosis of gastric diseases. In addition, MDCT can evaluate the involvement of the gastric wall and extragastric extent of the disease, as compared with gastroenteroscopy and double-contrast upper gastrointestinal study. Regarding lesion location and size, enhancing and growth patterns, presence of calcification or fat, and involvement of the gastric wall and adjacent structures, CT may provide useful information. In this review article, we review the relevant literature and discuss the CT features and the histopathologic findings of different types of gastric lesions. The lesions are divided into benign(glomus tumors, schwannomas, leiomyomas, and lipomas), malignant(gastrointestinal stromal tumors, mucinous carcinomas, lymphomas, and carcinoid tumors), and tumor-like lesions(ectopic pancreas and bezoar). Familiarity with imaging appearances and pathologic findings can help physicians make an accurate diagnosis.

Value of Multi-slice spiral CT in diagnosis of malignant gastrointestinal stromal tumors

Objective： The aim of this study was to investigate the value of multi-slice spiral CT （MSCT） in the diagnosis of malignant gastrointestinal stromal tumors （GISTs）. Methods： Twenty-seven cases of MSCT images of malignant GIST proved by surgery and pathology were retrospectively analyzed. Both plain and enhanced CT scan was performed and multiplanar reconstruction was made in all cases. Results： The lesions originated from the stomach （n = 11）, small intestine （n = 9）, colon （n = 4）, rectum （n = 1）, and mesentery （n = 2）. The transverse diameters of mass were 4.2-22 cm, the edges clearly （n = 12）, unclearly （n = 15）. The mass were mainly irregular in shape Iobulated （n = 19）. The lesions were mainly heterogeneity on plain scan, moderate to marked enhancement in arterial phase and durative enhanced in venous phase. Cystic necrosis were observed in all the lesions, 9 cases were cystic and solid mixed mass. Hepatic metastases （n = 4）, pulmonary metastasis （n = 1）, lymphatic metastasis （n = 2） were detected. The accuracy rate of MSCT diagnosis for location and pathologic features of GISTs were 85.2% （23/27） and 77.8% （21/27）. Conclusion： Two-phase MSCT examination and axial images combined with multiplanar reconstruction images have important value for diagnosis of malignant GIST.

Malignant giant cell tumors of the tendon sheath of the right hip:A case report

BACKGROUND Malignant giant cell tumor of the tendon sheath(MGCTTS)is an extremely rare malignant tumor originating from synovial and tendon sheath tissue with highly aggressive biological behavior and a high rate of local recurrence and distant metastasis which should be considered a highly malignant sarcoma and managed aggressively.How to systemically treat MGCTTS remains a challenge.In this case,a patient with MGCTTS suffered a recurrence after 2 surgical resections received adjuvant chemotherapy and radiation therapy,but the treatment outcome remained poor.More clinical trials and better understanding of the biology and molecular aspects of this subtype of sarcoma are needed while novel medicines should be developed to efficiently target particular pathways.CASE SUMMARY A 52-year-old man presented with persistent dull pain in the right groin accompanied by limited right hip motion starting 6 mo ago.Two months before his attending to hospital,the patient’s pain worsened,presenting as severe pain when standing or walking,limping,and inability to straighten or move the right lower extremity.Surgical excision was performed and MGCTTS was confirmed by pathology examination.Two recurrences occurred after surgical resection,moreover,the treatment outcome remained poor after adjuvant chemotherapy and radiation therapy.The patient died only 10 mo after the initial diagnosis.CONCLUSION MGCTTS is characterized by a joint mass with pain and limited motion.It typically grows along the tendons and infiltrated into the surrounding muscle and bone tissue,with a stubborn tendency to relapse,as well as pulmonary metastasis.Radically surgical resection provides a choice of treatment whereas post-operation care should be taken to preserve the function of the joint.Chemotherapy and radiotherapy can be used as alternative treatments when radical resection cannot be performed.

Pancreatic and peri-pancreatic lesions mimic pancreatic islet cell tumor in multidetector computed tomography

Objective This pictorial review aimed to summarize the most possible differential diagnosis of pancreatic islet cell tumor （PICT）. Data sources Data used in this review were mainly from Medline and Pubmed in English. And all clinical images in this review were from Department of Radiology, Peking Union Medical College Hospital, Beijing, China. Study selection Cases of pancreatic cystadenoma, solid pseudo-papillary tumor of the pancreas, pancreatic metastasis, pancreatic adenocarcinoma, para-pancreatic neuroendocrine tumors, Castleman disease, gastrointestinal stromal tumor, splenic artery aneurysm and accessory spleen were selected in this pictorial review for differential diagnosis of PICT.

Comparing Gross Tumor Volume of Delineation between CT and MRI for Nasopharyngeal Carcinoma

Objective: To study the accuracy between CT and MRI in delineating gross tumor volume (GTV) of nasopharyngeal carcinoma (NPC) in making radiotherapy plan. Methods: The clinical data of 39 cases pathologically proven as nasopharyngeal carcinoma selected from April 2003 to September 2004 were retrospectively analyzed. All were subjected to CT and MR examination one week before treatment. CT scanning was performed with GE Light speed 16, and axial scan was parallel to the OM line routinely from soft palate to the suprasellar cistern. MR scanning was performed by GE Signa super-conducting magnetic resonance imaging system (1.5 Tesla). The standard quadrature head coil was used. Routine axial, sagittal and coronal image with SE sequence were obtained, and FLAIR was used in 10 of 21 cases. Scanned field ranged from the soft palate to the suprasellar cistern. Part of all cases underwent enhanced scanned with Ultravist in CT group or/and GD-DTPA in MR group. All data were analyzed by using the paired-samples t test. Results: The media primary tumor volume (cm3) in CT group and MR group was 32.49±19.91, 29.06±18.75, respectively, and the difference between the two groups were significant (t=5.268, P=0.000). There was significant difference between the two groups in early stage (T1+T2) and advanced stage (T3+T4) by Fuzhou Staging System (t=5.677, P=0.000; t=3.310, P=0.005, respectively). There was significant difference in stage T1, T2, T3 (P=0.005, P=0.001, P=0.004, respectively), and not in stage T4 (P=0.146) between the two groups. Conclusion: MR was more accurate than CT in delineating GTV of NPC, so, is more valuable in making radiotherapy plan.

Primary pancreatic paraganglioma:A report of two cases and literature review

Paraganglioma is a rare tumor of paraganglia,derived from neural crest cells in sympathetic or parasympathetic ganglions.Primary paraganglioma originating from the pancreas is rare.We report two patients with paraganglioma in the head of the pancreas,in whom computed tomography showed a sharply marginated,hypervascular tumor with cystic areas.Significant intratumoral vessels and early contrast filling of the draining veins from the mass were not found.Although the pancreatic paraganglioma was located at the pancreatic head,the bile ducts often revealed no dilation,and sometimes the main pancreatic duct was mildly dilated.These findings are helpful in differentiating pancreatic paraganglioma from other pancreatic neoplasms.It is often difficult to distinguish between nonfunctional pancreatic paragangliomas and pancreatic endocrine tumors.In many reports,pancreatic paragangliomas show the retroperitoneal extension of a paraganglioma into the pancreas rather than a true pancreatic neoplasm.In surgical treatment,we could select simple excision of the tumor rather than radical surgery.

Malignant giant cell tumor in the left upper arm soft tissue of an adolescent:A case report

BACKGROUND Giant cell tumor of soft tissue(GCT-ST)is an extremely rare low-grade soft tissue tumor that is originates in superficial tissue and rarely spreads deeper.GCT-ST has unpredictable behavior.It is mainly benign,but may sometimes become aggressive and potentially increase in size within a short period of time.CASE SUMMARY A 17-year-old man was suspected of having a fracture,based on radiography following left shoulder trauma.One month later,the swelling of the left shoulder continued to increase and the pain was obvious.Computed tomography(CT)revealed a soft tissue mass with strip-like calcifications in the left shoulder.The mass invaded the adjacent humerus and showed an insect-like area of destruction at the edge of the cortical bone of the upper humerus.The marrow cavity of the upper humerus was enlarged,and a soft tissue density was seen in the medullary cavity.Thoracic CT revealed multiple small nodules beneath the pleura of both lungs.A bone scan demonstrated increased activity in the left shoulder joint and proximal humerus.The mass showed mixed moderate hypointensity and hyperintensity on T1-weighted images,and mixed hyperintensity on T2-weighted fat-saturated images.The final diagnosis of GCT-ST was confirmed by pathology.CONCLUSION GCT-STs should be considered in the differential diagnosis of soft tissue tumors and monitored for large increases in size.