Hypervascular subepithelial gastrointestinal masses: CT-pathologic correlation

Jejunal Cavernous Hemangioma Mimicking Malignancy With Increased Activity on 18 F-FDG PET/CT

ABSTRACT

A 50-year-old woman underwent 18 F-FDG PET/CT to evaluate possible abdominal malignancy, which was revealed by CT. The images showed a large cystic-solid lesion with peripherally increased FDG activity in the left mid-abdomen. Histopathology of the excised lesion confirmed a jejunal cavernous hemangioma. We reported a rare case of jejunal cavernous hemangioma with FDG accumulation on PET/CT, mimicking malignancy.

Correlation between pneumo-computed tomography and pathology findings for subepithelial gastric lesions

OBJECTIVE

This article aims to show the usefulness of the pneumo-computed tomography gastric distention technique in the detection and morphological characterization of subepithelial gastric lesions. We correlate the pneumo-computed tomography and pathology findings in lesions studied at our institution and review the relevant literature.

CONCLUSION

Pneumo-computed tomography, combined with multiplanar reconstructions, three-dimensional reconstructions, and virtual endoscopy, is useful for delineating the morphological details of subepithelial gastric lesions, thanks to the additional gastric distention. This technique better delimits and characterizes the upper and lower margins of the lesions. Pneumo-computed tomography can be considered a useful noninvasive imaging techniques for characterizing these lesions.

Metastatic Renal Cell Carcinoma Manifesting as a Gastric Polyp on CT: A Case Report and Literature Review

Gastric metastasis from renal cell carcinoma (RCC) is extremely rare, occurring in 0.2% of all RCC cases. Owing to its low prevalence, metachronous gastric metastasis from RCC may be underdiagnosed, and the imaging findings have not been well-established. Herein we present a case of metastatic RCC manifesting as a gastric polyp in a 70-year-old female along with a literature review on the imaging findings of gastric metastases from RCC. In patients presenting with gastric hyper-enhancing polypoid masses, metastasis from RCC should be considered as a differential diagnosis.

Primary Colonic Epithelioid Angiosarcoma with Hepatic Metastasis: A Case Report

Colonic angiosarcoma is an extremely rare and aggressive malignant tumor with poor prognosis. We report a case of colonic epithelioid angiosarcoma with colonic obstruction and rapidly progressive hepatic metastasis in a 44-year-old female. Abdominal CT revealed a heterogeneously enhancing irregular mass in the ascending colon, causing proximal bowel distension. The patient underwent surgery, and histopathological examination revealed a poorly differentiated carcinoma. A follow-up liver dynamic MRI after 4 months revealed newly developed diffusely scattered numerous small nodules in both hepatic lobes with peripheral and nodular marked arterial hyperenhancement, raising the suspicion of hepatic angiosarcoma. A pathologic second opinion was obtained, and additional immunohistochemistry revealed colonic epithelioid angiosarcoma. The patient showed progressive hepatic metastasis on follow-up abdominal CT after 6 months and died 8 months after initial diagnosis. We describe an educational case of colonic angiosarcoma, a rare malignant tumor, with rapidly progressive hepatic metastasis that showed radiologic findings suggestive of angiosarcoma and enabled a re-diagnosis for proper treatment and prognosis prediction.

Insight into gastrointestinal heterotopic pancreas: imaging evaluation and differential diagnosis

Heterotopic pancreas (HP) is an uncommon congenital abnormality in the developmental process of the pancreas, with gastrointestinal heterotopic pancreas (GHP) being the most common HP. The clinical manifestations of GHP may have variable patterns of presentation, dictated by both the anatomic location and the functional ability of the lesion. The most common imaging modality in detecting GHP is computed tomography (CT), while gastrointestinal barium fluoroscopy, endoscopic ultrasonography, and magnetic resonance imaging (MRI) are also applied. The density and enhancement patterns of GHP are consistent with histological classifications. GHP with a predominantly acinar tissue component manifests homogeneous and marked enhancement on CT images, whereas a predominantly ductal GHP presents heterogeneous and mild enhancement. On MRI, the appearance and signal intensity of GHP were paralleled to the normal pancreas on all sequences and were characterized by T1-weighted high signal and early marked enhancement. This article provides a comprehensive review of the histopathology, clinical manifestations, imaging features of various modalities, and differential diagnosis of GHP. It is hoped that this review will improve clinicians' knowledge of GHP and aid in accurate preoperative diagnosis, thereby reducing the misdiagnosis rate.

Novel endoscopic ultrasonography imaging technique for visualizing microcirculation without contrast enhancement in subepithelial lesions: Prospective study

OBJECTIVES

Detective flow imaging for endoscopic ultrasonography (DFI?EUS) is a new imaging modality developed for detecting fine vessels without using ultrasound contrast agents. This study aimed to evaluate its utility by comparing it with a type of directional power Doppler (eFLOW) for subepithelial lesions (SELs).

METHODS

Between January 2019 and January 2020, 28 patients with SELs undergoing DFI?EUS and eFLOW?EUS were enrolled. DFI?EUS and eFLOW?EUS assessing the vascularity in SELs were compared in terms of the rates of identification of intratumoral vessels. We also investigated how large vessels were depicted in both modalities based on surgical specimens as well as the detection rates of intratumoral vessels in gastrointestinal stromal tumors (GISTs) and non?GISTs using either DFI?EUS or eFLOW?EUS.

RESULTS

Among 28 patients, 23 with pathological confirmation by EUS?guided fine?needle aspiration biopsy (EUS?FNAB) specimens were included. Of those 23 patients, the 10 who underwent surgical resection were selected for analysis. The rate of detection of intratumoral vessels in SELs was significantly higher on DFI?EUS (80%) than on eFLOW?EUS (30%) (P\xA0=\xA00.03). Comparison with surgical specimens revealed that detection rate for vessels with maximum size of less 1000\xA0μm was higher in DFI?EUS (66%) than that in eFLOW?EUS (0%). GIST patients had significantly higher positive rates (90%) of intratumoral vessels than non?GIST patients (31%) on DFI in 23 cases including EUS?FNAB specimens (P\xA0=\xA00.045).

CONCLUSIONS

Detective flow imaging?EUS is more sensitive for depicting intratumoral vessels than eFLOW?EUS. Evaluation of intratumoral vessels on DFI?EUS is useful for identifying GISTs without contrast agents.

Tumor desmoide abdominal gigante en puerperio: caso clínico y revisión de la literatura

Introducción. Los tumores desmoides o fibromatosis agresiva corresponden a neoplasias mesenquimales poco frecuentes. Son tumores localmente agresivos que ocurren especialmente en jóvenes, no desarrollan metástasis a distancia, pero se asocian con invasión locorregional y alta tasa de recurrencia después de la resección. Su etiología es desconocida, pero se ha asociado al síndrome de Gardner, trauma, embarazo, estados hiperestrogénicos y puerperio. El objetivo de este artículo fue hacer una revisión sobre el tema a propósito de un caso clínico. Caso clínico. Se presenta el caso de una paciente puérpera con progresivo y rápido aumento del volumen abdominal. Se realizó una tomografía computarizada de abdomen y pelvis que confirmó la presencia de una masa intraperitoneal bien definida. La paciente fue operada con escisión de la masa y confirmación histológica de tumor desmoide a partir de la muestra de patología. Discusión. Los tumores desmoides tienen una incidencia de 2 a 4 casos por millón de habitantes por año, con leve predominio en el sexo femenino y representan menos del 3 % de los tumores de partes blandas. Aunque el tumor se puede ubicar a nivel intraabdominal o en la pared, la ubicación más común es en las extremidades. Conclusiones. La sospecha y detección del tumor desmoide es fundamental, así como su adecuado estudio, para determinar el tratamiento quirúrgico como fue realizado en este caso.

Castleman's Disease Arising from the Hepatoduodenal Ligament Mimicking a Duodenal Gastrointestinal Stromal Tumor

Castleman's disease (CD) arising from the hepatoduodenal ligament is extremely rare. A 32-year-old man was referred to a clinic with nausea. He was found to have an abdominal mass by ultrasonography and consulted our hospital for further examination. Computed tomography revealed an equally enhancing mass, 5.2 cm in diameter, adjacent to the duodenum. On magnetic resonance imaging, the mass revealed a slightly iso-intensity signal equal to smooth muscle on T1-weighted imaging, a slightly high-intensity signal on T2-weighted imaging, and a high-intensity signal on diffusion-weighted imaging. Endoscopic ultrasonography showed a well-demarcated hypoechoic mass adjacent to the duodenum. The Doppler echo pattern indicated abundant blood flow. The preoperative diagnosis was a duodenal gastrointestinal stromal tumor. The patient underwent laparotomy and tumor excision. The finding of the intraoperative frozen section was CD. Histologically, the lymph follicles were markedly increased in number throughout the cortex and medulla with vascular proliferation and hyalinization in the intra- or extra-follicles. The germinal centers were atrophic and surrounded by concentrically arranged layers of small lymphocytes. The histological findings were the hyaline vascular variant of CD. If a hypervascular solid mass is detected in the abdomen, CD should be considered in the differential diagnosis.

Cross-Sectional Imaging Evaluation of Vascular Lesions in the Gastrointestinal Tract and Mesentery

Gastrointestinal (GI) tract and mesenteric vascular lesions can have various clinical presentations, of which GI bleeding is the most common. This collection of pathology is highly variable in etiology ranging from occlusive disease to vascular malformations to trauma to neoplasms which makes for a challenging workup and diagnosis. The advent of multiple imaging modalities and endoscopic techniques makes the diagnosis of these lesions more achievable, and familiarity with their various imaging findings can have a significant impact on patient management. In this article, we review the gamut of GI tract and mesenteric vascular lesions and their associated imaging findings.

Periampullary duodenal schwannoma mimicking ampullary neoplasm

Schwannomas are neurogenic tumors that arise from Schwann cells in the neural sheath. Gastrointestinal schwannomas occur most often in the stomach, followed by the colon and the rectum. Duodenal schwannomas are rare amongst mesenchymal tumors of the gastrointestinal tract and only a few cases have been reported up to the current date with an incidence of approximately 2%-6%. Duodenal Schwannomas do not have characteristic imaging features thereby cannot be easily differentiated from other submucosal and adjacent extraluminal neoplasms. We present a case of a 76-year old male patient that presented to our hospital with abdominal pain and was diagnosed after an upper gastrointestinal endoscopy with an ampullary duodenal neoplasm that proved to be a periampullary duodenal Schwannoma on histopathology. Duodenal Schwannomas although rare should be considered in the differential diagnosis of ampullary neoplasms.

Small bowel racemose hemangioma complicated with obstruction and chronic anemia: A case report and review of literature

BACKGROUND

Gastrointestinal hemangiomas are rare benign tumors. According to the size of the affected vessels, hemangiomas are histologically classified into cavernous, capillary, or mixed-type tumors, with the cavernous type being the most common and racemose hemangiomas being very rare in the clinic. Melena of uncertain origin and anemia are the main clinical manifestations, and other presentations are rare. Due to the rarity of gastrointestinal hemangiomas and lack of specific manifestations and diagnostic methods, preoperative diagnoses are often delayed or incorrect.

CASE SUMMARY

We report a 5-year-old girl who presented with abdominal pain, nausea, and vomiting for a duration of 10 h. The laboratory studies showed prominent anemia. Computed tomography and contrast-enhanced computed tomography of the abdomen revealed a small bowel obstruction caused by a giant abdominal mass. Segmental resection of the ileal lesions was performed through surgery, and the final pathology results revealed a diagnosis of racemose hemangioma complicated by a small bowel obstruction and simultaneous chronic anemia.

CONCLUSION

The current report will increase the understanding of the diagnosis and treatment of gastrointestinal hemangiomas and provide a review of the related literature.

Beyond adenocarcinoma: MRI of uncommon rectal neoplasms and mimickers

OBJECTIVE

To provide a review of rare rectal tumors beyond adenocarcinoma.

RESULTS

Rectal cancer is a common malignancy, both in the United States and abroad. In addition to adenocarcinoma, abdominal radiologists will encounter a variety of other less common rectal masses, both benign and malignant neoplasms as well as non-neoplastic mimickers. Familiarity with these conditions and their characteristic features on MRI is useful in clinical practice. In this article, a number of such conditions are discussed, with an emphasis on distinguishing features on MRI of the rectum.

CONCLUSION

Familiarity with the MRI features of rare rectal tumors beyond adenocarcinoma, as well as a small number of non-neoplastic mimics, is important for abdominal imagers to make diagnostic differentials and to assist in treatment planning.

Differentiation of duodenal gastrointestinal stromal tumors from hypervascular pancreatic neuroendocrine tumors in the pancreatic head using contrast-enhanced computed tomography

PURPOSE

To determine useful contrast-enhanced computed tomography (CE-CT) features in differentiating duodenal gastrointestinal stromal tumors (duodenal GISTs) from hypervascular pancreatic neuroendocrine tumors in the pancreatic head (pancreatic head NETs).

METHODS

Seventeen patients with pathologically confirmed duodenal GISTs and 25 with pancreatic NETs underwent preoperative CE-CT. CT image analysis included tumor size, morphology, and contrast enhancement. Receiver operating characteristic curves were performed, and cutoff values were calculated to determine CT findings with high sensitivity and specificity.

RESULTS

CT imaging showed duodenal GISTs with higher frequencies of tumor central location close to the duodenum and a predominantly solid tumor type when compared with pancreatic head NETs (p < 0.05 for both). Duodenal GISTs were larger than pancreatic head NETs (3.3 ± 0.9 cm vs. 2.5 ± 1.1 cm, p = 0.03). Duodenal GISTs had significantly lower CT attenuation values (112.9 ± 17.9HU vs. 137.4 ± 32.1HU, p < 0.01) at the arterial phase and higher CT attenuation values at the delayed phase (94.3 ± 7.9HU vs. 84.9 ± 10.4HU, p < 0.01) when compared with pancreatic head NETs. A CT attenuation value of ≤ 135 HU at the arterial phase (30 s) was 76% sensitive, 94.1% specific, and 83.3% accurate for the diagnosis of duodenal GISTs, while a CT attenuation value of ≥ 89.5 HU at the delayed phase (120 s) was 93.3% sensitive, 81.8% specific, and 76.2% accurate for the diagnosis of duodenal GISTs.

CONCLUSION

Tumor central location, size, texture, and contrast enhancement are valuable characteristics for the differentiation between duodenal GISTs and hypervascular pancreatic head NETs during preoperative examination.

Tumor heterogeneity in gastrointestinal stromal tumors of the small bowel: volumetric CT texture analysis as a potential biomarker for risk stratification

Background

To explore whether volumetric CT texture analysis (CTTA) can serve as a potential imaging biomarker for risk stratification of small bowel gastrointestinal stromal tumors (small bowel-GISTs).

Methods

A total of 90 patients with small bowel-GISTs were retrospectively reviewed, of these, 26 were rated as high risk, 13 as intermediate risk, and 51 as low or very low risk. Histogram parameters extracted from CT images were compared among small bowel-GISTs with different risk levels by using one-way analysis of variance. Receiver operating characteristics (ROCs) and areas under the curve (AUCs) were analyzed to determine optimal histogram parameters for stratifying tumor risk.

Results

Significant differences in mean attenuation, 10th, 25th, 50th, 75th and 90th percentile attenuation, and entropy were found among high, intermediate, and low risk small bowel-GISTs (p ≤ 0.001). Mean attenuation, 10th, 25th, 50th, 75th and 90th percentile attenuation, and entropy derived from arterial phase and venous phase images correlated significantly with risk levels (r = 0.403–0.594, r = 0.386–0.593, respectively). Entropy in venous phase reached the highest accuracy (AUC = 0.830, p < 0.001) for differentiating low risk from intermediate to high risk small bowel-GISTs, with a cut-off value of 5.98, and the corresponding sensitivity and specificity were 82.4 and 74.4%, respectively.

Conclusions

Volumetric CT texture features, especially entropy, may potentially serve as biomarkers for risk stratification of small bowel-GISTs.

Contrast-enhanced computed tomography may be helpful for characterizing and staging canine gastric tumors

In humans, computed tomography (CT) is a widely performed technique for the diagnosis and staging of gastric tumors. The purpose of this retrospective case series study was to describe CT findings in a group of dogs with confirmed gastric tumors. For each included dog, the following CT parameters were recorded: gastric tumor location, tumor shape, gastric involvement pattern, tumor enhancement pattern in early and late phases, presence and location of lymphadenopathy, gastric tumor attenuation values, attenuation values of enlarged lymph nodes, maximum short-axis diameter (mm) of enlarged lymph node, maximum long-axis diameter (mm) of enlarged lymph node, and short-axis diameter to long-axis diameter ratio (short axis/long axis). A total of 16 dogs met inclusion criteria and had the following final diagnoses: five lymphoma, six adenocarcinoma, three inflammatory polyps, and two leiomyoma. In the early- and delayed-phase postcontrast images, the mean CT attenuation value for lymphoma was lower than that of other gastric tumors. Lymphadenopathy was widespread in lymphomas and regional in adenocarcinomas. Lymphadenopathy was not detected in leiomyomas. Lymph node measurements in lymphoma were larger than lymph node measurements in adenocarcinoma. Although there were overlapping findings for the different types of gastric tumors, contrast-enhanced CT provided helpful information for characterizing gastric tumors based on the following criteria: early and late enhancement patterns, the site of origin of the mass lesion, and extent of local invasion and distant metastases. Lymphoma should be considered for canine gastric tumors with low mean attenuation values during early- and delayed-phase postcontrast images, and widespread, bulky, and rounded lymphadenopathy.

Haemangiomas of the Small Intestine: Poorly Known Cause of Gastrointestinal Bleeding of Uncertain Origin

Small bowel haemangiomas are benign vascular tumours that may cause gastrointestinal bleeding of uncertain origin, are frequently chronic, and are rarely acute. We report a case of an haemangioma located in the distal ileum of a 29-year-old male with a history of chronic anemia since childhood. Imaging studies showed a mural thickening in the distal ileum with phleboliths, which is a key finding of haemangioma. Surgery was performed, and histology confirmed the diagnosis.

Evaluating the Sensitivity of Arterial Phase CT Images for Detection of Hepatic GIST Metastases

Gastrointestinal stromal tumor (GIST) frequently metastasizes to the liver, and conventional staging computed tomography (CT) protocols use multiphasic contrast enhancement for detection of hepatic lesions. We evaluated the sensitivity of arterial phase CT imaging for hepatic GIST metastases compared with that of standard (portal venous [PV]) phase imaging. We conducted a retrospective review of patients who presented with hepatic GIST metastases identified on staging CT examinations between 2005 and 2015. Arterial and PV phase CT images were randomized and reviewed by 2 radiologists blinded to clinical history, correlative imaging, and number of controls. In total, 32 patients had hepatic metastases identified on multiphasic (arterial and PV) staging CT examinations. There was no significant difference in identification of metastases between arterial and PV phase imaging (31 vs 32, P = .32). Lesion size measurements did not significantly differ (P = .58). Arterial phase CT imaging did not significantly increase the sensitivity for hepatic GIST metastases compared with PV phase imaging alone.

Heterotopic Pancreas: Histopathologic Features, Imaging Findings, and Complications

Heterotopic pancreas is a congenital anomaly in which pancreatic tissue is anatomically separate from the main gland. The most common locations of this displacement include the upper gastrointestinal tract-specifically, the stomach, duodenum, and proximal jejunum. Less common sites are the esophagus, ileum, Meckel diverticulum, biliary tree, mesentery, and spleen. Uncomplicated heterotopic pancreas is typically asymptomatic, with the lesion being discovered incidentally during an unrelated surgery, during an imaging examination, or at autopsy. The most common computed tomographic appearance of heterotopic pancreas is that of a small oval intramural mass with microlobulated margins and an endoluminal growth pattern. The attenuation and enhancement characteristics of these lesions parallel their histologic composition. Acinus-dominant lesions demonstrate avid homogeneous enhancement after intravenous contrast material administration, whereas duct-dominant lesions are hypovascular and heterogeneous. At magnetic resonance imaging, the heterotopic pancreas is isointense to the orthotopic pancreas, with characteristic T1 hyperintensity and early avid enhancement after intravenous gadolinium-based contrast material administration. Heterotopic pancreatic tissue has a rudimentary ductal system in which an orifice is sometimes visible at imaging as a central umbilication of the lesion. Complications of heterotopic pancreas include pancreatitis, pseudocyst formation, malignant degeneration, gastrointestinal bleeding, bowel obstruction, and intussusception. Certain complications may be erroneously diagnosed as malignancy. Paraduodenal pancreatitis is thought to be due to cystic degeneration of heterotopic pancreatic tissue in the medial wall of the duodenum. Recognizing the characteristic imaging features of heterotopic pancreas aids in differentiating it from cancer and thus in avoiding unnecessary surgery. ^© RSNA, 2017.

[The Diagnosis of Metastatic Malignant Melanoma Incidentally Found during a National Health Screening Endoscopy: A Case Report]

Malignant melanoma is one of the most common malignant diseases of the gastrointestinal tract. It has been reported that the malignant melanoma metastasizes not only to the small intestine due to the abundant blood supply, but also to the stomach, colon, and esophagus. Gastrointestinal metastasis is usually suspected depending on the clinical symptoms, as well as based on radiological or endoscopic findings. Imunohistochemical stains, such as Melan-A/Melanoma antigen recognized by T cell-1 or human melanoma black-45, are useful for confirming the diagnosis of malignant melanoma. A 44-year-old male received an operation due to a malignant melanoma at the left thumb two years ago. On the national health screening endoscopy, a submucosal tumor with hyperemic change on the top was found. The final diagnosis was a metastatic malignant melanoma in the stomach, pancreas, and pelvic bone. We recommend that endoscopists should consider the potential malignancy of subepithelial tumor with mucosa change, despite the tumor size being less than 1 cm.

[Obscure gastrointestinal bleeding due to gastrointestinal stromal tumors]

BACKGROUND

The gastrointestinal stromal tumours (GIST) are the most common soft tissue sarcomas of the digestive tract. They are usually found in the stomach (60-70%) and small intestine (25-30%) and, less commonly, in the oesophagus, mesentery, colon, or rectum. The symptoms present at diagnosis are, gastrointestinal bleeding, abdominal pain, abdominal mass, or intestinal obstruction. The type of symptomatology will depend on the location and size of the tumour. The definitive diagnosis is histopathological, with 95% of the tumours being positive for CD117.

CLINICAL CASES

This is an observational and descriptive study of 5cases of small intestinal GIST that presented with gastrointestinal bleeding as the main symptom. The period from the initial symptom to the diagnosis varied from 1 to 84 months. The endoscopy was inconclusive in all of the patients, and the diagnosis was made using computed tomography and angiography. Treatment included resection in all patients. The histopathological results are also described.

CONCLUSION

GIST can have multiple clinical pictures and unusual symptoms, such as obscure gastrointestinal bleeding. The use of computed tomography and angiography has shown to be an important tool in the diagnosis with patients with small intestine GISTs.

Computed tomography features and predictive findings of ruptured gastrointestinal stromal tumours

OBJECTIVES

To evaluate the CT features of ruptured GISTs and factors that might be predictive of rupture through comparison with CTs taken prior to rupture and CTs of non-ruptured GIST.

METHODS

Forty-nine patients with ruptured GIST and forty-nine patients with non-ruptured GIST matched by age, gender and location were included. Clinical data including pharmacotherapy were reviewed. The imaging features were analyzed. Prior CT obtained before rupture were evaluated.

RESULTS

The most common location of ruptured GIST was small bowel with mean size of 12.1 cm. Ruptured GIST commonly showed wall defects, >40 % eccentric necrosis, lobulated shaped, air density in mass, pneumoperitoneum, peritonitis, hemoperitoneum and ascites (p < 0.001-0.030). Twenty-seven of 30 patients with follow up imaging received targeted therapy. During follow-up, thickness of the tumour wall decreased. Increase in size and progression of necrosis were common during targeted therapy (p = 0.017). Newly developed ascites, peritonitis and hemoperitoneum was more common (p < 0.001-0.036).

CONCLUSION

Ruptured GISTs commonly demonstrate large size, >40 % eccentric necrosis, wall defects and lobulated shape. The progression of necrosis with increase in size and decreased wall thickness during targeted therapy may increase the risk of rupture. Rupture should be considered when newly developed peritonitis, hemoperitoneum, or ascites are noted during the follow-up.

KEY POINTS

• Ruptured GISTs demonstrate large size, eccentric necrosis, wall defects, and lobulated shape. • Rupture should be considered when peritonitis or hemoperitoneum/adjacent hematoma newly appears. • Progression of necrosis with increase in size increases the risk of rupture.

Inflammatory fibroid polyps of the gastrointestinal tract: a 14-year CT study at a single institution

PURPOSE

To investigate the computed tomography (CT) features of pathology-proven inflammatory fibroid polyps (IFPs) in the gastrointestinal tract.

METHODS

This retrospective series study included 27 patients with pathology-proven IFPs in the stomach (n = 16), small (n = 9), and large (n = 2) intestine, who underwent contrast-enhanced CT. Two radiologists reviewed the CT images of the patients to determine in consensus the long diameter, shape, margin, contour, and growth pattern of the lesions, the presence of an ulcer and overlying mucosal hyperenhancement, the lesion enhancement patterns including the homogeneity and the degree of contrast enhancement, and the presence of intussusception and obstruction. The CT results and clinical data of the gastric and intestinal lesions were compared.

RESULTS

The IFPs typically manifested as well-defined (89%), round or ovoid (81%), slightly lobulated-contoured (70%) masses with a purely endoluminal growth pattern (96%) and an overlying mucosal hyperenhancement (67%). Lesion homogeneity and the degree of contrast enhancement varied. The intestinal IFPs were significantly larger (3.5 vs. 2 cm), more symptomatic (82% vs. 19%), and more frequently associated with intussusception (73% vs. 0%) and obstruction (46% vs. 6%) than the gastric lesions (p ≤ 0.027).

CONCLUSIONS

The characteristic CT features of IFPs were well-defined, round or ovoid, lobulated-contoured, and endoluminal masses with overlying mucosal hyperenhancement and various enhancement patterns. IFP should be included in the differential diagnosis of patients with a soft-tissue mass in the gastrointestinal tract, especially if a large endoluminal mass in the small intestine is accompanied by intussusception.

Combined Undifferentiated and Neuroendocrine Carcinomas of the Gallbladder Appearing as Two Separate Lesions: A Case Report with Radiological-Pathological Correlation

We report herein a rare case of incidentally detected combined undifferentiated and neuroendocrine carcinomas of the gallbladder. An incidental gallbladder malignancy was revealed on abdominal ultrasound and multi-detector computed tomography in a 54-year-old man. A short distance from the main polypoid hypoechoic mass at the fundus of the gallbladder, focal wall thickening was noted with prominently increased power Doppler flow. Extended cholecystectomy was performed, and histology confirmed the main polypoid mass as undifferentiated carcinoma and the separate nodule as neuroendocrine carcinoma. To our knowledge, this is the first report presenting two separate lesions of combined gallbladder carcinomas by radiological features.

Heterotopic pancreas of the jejunum: associations between CT and pathology features

PURPOSE

To investigate the computed tomography (CT) features of heterotopic pancreas of the jejunum (HPJ) and to assess their associations with HPJ pathology features.

METHODS

In this retrospective series analysis, two radiologists reviewed the CT images of 17 patients with surgically proven HPJ in order to determine in consensus the location, long diameter, margin, shape, contour, and growth pattern of the lesions, the presence of a duct-like structure, the lesion enhancement patterns, including the homogeneity, and the degree of contrast enhancement compared with that of the main pancreas. The pathology features of the surgical specimens were reviewed and their associations with the CT features were assessed.

RESULTS

On CT, the HPJs typically appeared as a small (<3 cm), well-defined, ovoid or flat-shaped mass in the proximal jejunum with multiple and tiny lobulations. The growth pattern varied and the duct-like structure was rarely visible. The HPJs mostly appeared to be homogeneous and exhibited hyper- or isoattenuation compared to the main pancreas in the arterial and portal phases. However, these enhancement patterns varied slightly depending on the microscopic composition of the lesions (i.e., acinar vs. ductal predominance). Most HPJs comprised histologically of large acini, some ducts, and small islet cells, and had ductal communication with the jejunum.

CONCLUSIONS

HPJs typically manifested as small, well-defined, ovoid or flat-shaped, homogeneous, and well-enhancing masses with a microlobulated contour in the proximal jejunum on CT, and their enhancement patterns associated with their microscopic composition. The pathology features of HPJs generally mimic those of the normal pancreas.

Endoscopic ultrasound-guided sampling of a metastatic mucinous adenocarcinoma mimicking a gastric subepithelial tumor

Metastatic mucinous adenocarcinoma of appendix origin and mimicking a gastric subepithelial tumor (SET) is very rare. Endoscopic ultrasound (EUS)-guided sampling is a useful diagnostic method for SETs. However, the cytologic findings of metastatic mucinous adenocarcinoma are unfamiliar to many pathologists and gastroenterologists. These findings present a diagnostic challenge because the introduction of gastric epithelium and mucin into the specimen during the procedure can be misleading. This is the first reported experience of an EUS-guided sampling of a gastric SET in a patient with suspected appendiceal tumor, to make the diagnosis of a mucinous adenocarcinoma.

Computed tomography and clinical characteristics of gastric glomus tumors

OBJECTIVE

To provide a retrospective assessment of clinical characteristics of the patients with gastric glomus tumors and the imaging features of the tumors on multidetector row computed tomography (MDCT).

METHODS

Consecutive patients with gastric glomus tumor which was confirmed by postoperative pathology from January 2004 to January 2012 in a tertiary hospital were included in the study. The MDCT images and medical records of the patients including the imaging features of the tumor on MDCT such as its location, number, shape, growth pattern, size, density and enhancement pattern were retrospectively reviewed.

RESULTS

Altogether ten patients were included in the study, including seven women and three men, with a mean age of 46.6 years (range 25-67 years). Most patients had nonspecific clinical symptoms. All lesions were located at the gastric antrum, with a mean diameter of 2.7 cm. The gastric glomus tumor showed strong enhancement at the arterial phase, a progressive filled-in enhanced pattern and prolonged enhancement during multiphasic scans.

CONCLUSIONS

Gastric glomus tumor is clinically an extremely rare disease. The combination of tumor location, size and the characteristic enhancement pattern of the subepithelial lesion may suggest a diagnosis of gastric glomus tumor.

Imaging findings of primary gastric plasmacytoma: A case report

Primary gastric plasmacytoma (GP) is a rare extramedullary plasmacytoma with clinical and imaging features that are common among other gastric tumors, such as gastric adenocarcinomas, gastric stromal tumors, and lymphomas. Here, we present a histologically confirmed case of primary GP examined with biphasic computed tomography (CT), magnetic resonance imaging (MRI), and endosonography. A well-circumscribed extraluminal mass appearing as homogeneous attenuation/intensity with gradual enhancement was identified on biphasic enhancement CT and MRI. This mass was hyperintense on diffusion-weighted imaging and hypointense on the apparent diffusion coefficient map, implying that water diffusion in the mass was restricted. In addition, endosonography indicated a low echogenic mass in the gastric wall. These imaging findings increase the available knowledge about imaging of this disease and provide valuable information for differentiating primary GP from common gastric tumors.

Beyond the GIST: mesenchymal tumors of the stomach

Intramural gastric masses arise in the wall of the stomach (generally within the submucosa or muscularis propria), often with intact overlying mucosa. These tumors are typically mesenchymal in origin and have overlapping radiologic appearances. A combination of features such as location, attenuation, enhancement, and growth pattern may suggest one diagnosis over another. Gastrointestinal stromal tumors (GISTs) account for the majority of intramural tumors and can vary widely in appearance, from small intraluminal lesions to exophytic masses that protrude into the peritoneal cavity, commonly with areas of hemorrhage or necrosis. A well-circumscribed mass measuring -70 to -120 HU is a lipoma. Leiomyomas usually manifest as low-attenuation masses at the gastric cardia. Homogeneous attenuation is a noteworthy characteristic of schwannomas, particularly for larger lesions that might otherwise be mistaken for GISTs. A hypervascular mass in the antrum is a common manifestation of glomus tumors. Hemangiomas are also hypervascular but often manifest in childhood. Inflammatory fibroid polyps usually arise as a polypoid mass in the antrum. Inflammatory myofibroblastic tumors are infiltrative neoplasms with a propensity for local recurrence. Plexiform fibromyxomas are rare, usually antral tumors. Carcinoid tumors are epithelial in origin, but often submucosal in location, and therefore should be distinguished from other intramural lesions. Multiple carcinoid tumors are associated with hypergastrinemia, either in the setting of chronic atrophic gastritis or Zollinger-Ellison syndrome. Sporadic solitary carcinoid tumors not associated with hypergastrinemia have a higher rate of metastasis. Histopathologic analysis, including immunohistochemistry, is usually required for diagnosis of intramural masses.

Multimodality imaging evaluation of an uncommon entity: esophageal heterotopic pancreas

A 25-year-old male was referred to the Radiology Department with new onset of right upper quadrant and epigastric abdominal pain. He had no past medical or surgical history. Physical exam was unremarkable. The patient underwent computed tomography (CT), fluoroscopic upper gastrointestinal (GI) evaluation, endoscopic ultrasound (EUS), and positron emission tomography (PET) evaluation, revealing the presence of a heterogeneous esophageal mass. In light of imaging findings and clinical workup, the patient was ultimately referred for thorascopic surgery. Surgical findings and histology confirmed the diagnosis of esophageal heterotopic pancreas.

From the radiologic pathology archives: esophageal neoplasms: radiologic-pathologic correlation

Esophageal neoplasms have a wide spectrum of clinical features, pathologic findings, and imaging manifestations. Leiomyomas are the most common benign esophageal neoplasm, typically appearing as smoothly marginated intramural masses. Fibrovascular polyps arise in the cervical esophagus, gradually elongating as they are pulled inferiorly by esophageal peristalsis. Granular cell tumors are generally incidental small intramural masses with an appearance similar to that of leiomyomas. Malignant esophageal neoplasms are a common cause of cancer mortality, particularly squamous cell carcinoma (SCC) and adenocarcinoma. Both of these tumors occur in older men, most often appearing as irregular infiltrative lesions at barium examination, with evidence of tumor spread beyond the esophagus at cross-sectional imaging. Adenocarcinoma arises from Barrett esophagus and is much more likely than SCC to involve the gastroesophageal junction. Esophageal involvement by lymphoma is usually secondary to tumor spread from the stomach or mediastinum. Spindle cell carcinoma is a biphasic malignancy with carcinomatous and sarcomatous elements that forms a bulky polypoid intraluminal mass. Neuroendocrine carcinoma is an aggressive neoplasm that may be hypervascular and is usually associated with metastatic disease at presentation. Understanding the imaging appearances and pathologic bases of esophageal neoplasms is essential for their detection, differential diagnosis, staging, and treatment planning.

Case 200: Gastric enterochromaffinlike cell tumors in a patient with type 1 multiple endocrine neoplasia

History A 55-year-old man presented with chronic epigastric pain lasting for about 1 year and without fever or vomiting. The abdomen was soft and tender at physical examination. Laboratory tests revealed unremarkable liver function, normal hemoglobin level, and normal amylase level. White blood cell count was normal, and there was no inflammatory syndrome. The patient's medical history included pancreatic gastrinoma resected by means of left pancreatectomy 31 years before, hyperparathyroidism treated with subtotal parathyroidectomy 24 years before, and a slowly growing lung mass known for 9 years. Esophagogastroduodenoscopy was performed because of a suspected gastroduodenal ulcer. The results showed numerous small (<10 mm) gastric and duodenal ulcers and multiple 10-15-mm polypoid gastric masses. Contrast material-enhanced dual-phase multidetector row computed tomography (CT) of the chest and abdomen was performed with a 64-section CT scanner (LightSpeed VCT; GE Healthcare, Milwaukee, Wis). Technical parameters for CT were as follows: pitch, 0.98; section thickness and reconstruction interval, 1.25 mm; 120 kVp; and variable milliamperage determined by x-, y-, and z-axis dose modulation. After an unenhanced abdominal scan, iobitridol, a nonionic iodinated contrast agent containing 350 mg of iodine per milliliter (Xenetix 350; Guerbet, Aulnay-sousbois, France), was administered intravenously through a 16-18-gauge catheter. A 120-mL dose of the contrast agent was injected via an antecubital vein at a rate of 4 mL/sec. No oral contrast medium was administered. After preliminary unenhanced abdominal scanning, arterial and portal venous phase acquisitions were obtained 45 and 80 seconds after initiation of contrast medium injection.

CT and MR imaging of gastrointestinal stromal tumor of stomach: a pictorial review

This pictorial review illustrates CT and MR imaging appearance of gastrointestinal stromal tumor (GIST) of the stomach and other lesions with similar imaging appearance. GIST of the stomach appears as well-defined enhanced masses with characteristics of subeppthial neoplasms. Majority are exophytic growth, but can also be of intra-luminal growth. GIST can growth into a large mass without gastrointestinal tract obstruction. Necrosis is often seen in GIST and results in heterogeneous enhancement and communication with gastrointestinal tract. CT and MRI features of several other neoplasms mimicking GISTs in the stomach are also described in this review.

Gastric subepithelial masses: evaluation of multidetector CT (multiplanar reconstruction and virtual gastroscopy) versus endoscopic ultrasonography

OBJECTIVES

To assess the role of multidetector computed tomography (MDCT) with multiplanar reconstruction (MPR) and virtual gastroscopy (VG) for detection and differentiation of gastric subepithelial masses (SEMs) by comparison with endoscopic ultrasonography (EUS).

METHODS

Forty-one patients with a suspected SEM were evaluated using EUS and MDCT. MDCT findings were analyzed based on the consensus of two radiologists who were blinded to the EUS findings. The analysis of the CT features included the location, size, and contours of the tumor, the presence of central dimpling, as well as the growth pattern, enhancement pattern, and enhancement degree. The long diameter (LD) and the short diameter (SD) of each lesion were measured and the LD/SD ratios were calculated. EUS and MDCT results were compared with histopathology for the pathologically proven lesions. For the non-pathologically proven lesions, MDCT results were compared with EUS.

RESULTS

Among the 41 patients, 34 SEMs were detected using EUS. For the detection of SEMs with MDCT, a sensitivity of 85.3%, a specificity of 85.7%, a positive predictive value of 96.7%, and a negative predictive value of 54.5% were calculated. The overall accuracy of MDCT for detecting and classifying the SEMs was 85.3 and 78.8%, respectively.

CONCLUSIONS

MDCT with MPR and VG is a valuable method for the evaluation of SEMs. Specific MDCT criteria for various SEMs may be helpful in making an accurate diagnosis.

Gastric glomus tumor: analysis of endosonographic characteristics and computed tomographic findings

Among submucosal tumors (SMT), gastric glomus tumors are rare vascular tumors, and only a few cases where glomus tumors have been differentiated from other mesenchymal tumors by endoscopic ultrasonography (EUS) or computed tomography (CT) have been reported. In this case series, we aimed to analyze the EUS and CT characteristics of gastric glomus tumors. Seven patients with gastric glomus tumors were retrospectively enrolled in this study. EUS showed that all the tumors were located in the fourth EUS layer (muscularis propria) and had distinct borders. The tumors had a heterogeneous appearance with either hypo- or hyperechogenicity, and all the tumors except one had the characteristic peripheral halo around them. On CT scans,all the tumors appeared as well-defined SMT with a clear margin and showed the same characteristics in the different phases of CT. During dynamic contrast-enhanced CT, the tumors showed strong enhancement in the arterial phase and prolonged enhancement in the delayed phase. This case series shows the characteristic EUS findings and the distinguishing features of CT scans for gastric glomus tumors; these findings will help in differentiating gastric glomus tumors from other SMT.