US and CT findings of small bowel neoplasms

Small bowel (SB) neoplasms are very rare tumours, but are still associated with high mortality rates, since the tumour-related symptoms occur late and are non-specific. In addition, endoscopy is not feasible in most cases, and radiological contrast studies do not reach the high accuracy obtained in the evaluation of upper and lower gastrointestinal tract. Cross-sectional imaging, and particularly CT, is becoming increasingly relevant in the diagnosis of these tumours. Both US and CT allow tumour detection, even when performed on an emergency basis, and are capable of showing the lesion as well as possible complications. Moreover, CT offers the possibility of a preoperative staging by evaluating tumour extension through the bowel wall, lymph node involvement and possible metastases. Finally, in most cases a direct correlation between cross-sectional findings and histology can be found, thus permitting tumour characterisation. Received 27 June 1996; Revision received 11 October 1996; Accepted 4 February 1997     

Abdominal wall lipoma--CT and MRI appearance.

Although soft tissue lipomata are common tumours, a large lipoma arising from the deep layers of the abdominal wall would appear to be excessively rare and the site of origin may be difficult to determine. The CT and MRI appearances of such a tumour are described.     

CT and MRI findings of intraosseous schwannoma of the mandible: a case report

We report the radiographical findings of a rare case of intraosseous schwannoma of the mandible. The tumour that presented as a unilocular, well-defined, radiolucent lesion on plain radiography was located in the molar region. On CT, the tumour was a well-demarcated mass with no periosteal reaction and no destruction of the bone cortex. Destructive changes in the cortical wall of the mandibular canal by the tumour were observed on CT, but no evidence of dilatation and shift in the inferior mandibular canal was seen. MR imaging revealed that the mandibular canal was encased by the tumour as a solid mass without cystic parts. The signal intensity of the tumour was non-specific on MRI. Characteristics of intraosseous schwannoma in the mandible are the encasement of the canal by a well-demarcated tumour without periosteal reaction and the destruction of mandibular bone cortex. The destructive change of the inferior mandibular canal can be observed on CT and MRI. However, a biopsy is necessary to make the final diagnosis because of the non-specificity of the findings.     

Tumour of the diaphragm mimicking liver lesion.

Tumours of the diaphragm bordering the liver may impose diagnostic difficulties. We report the case of a 46-year-old patient diagnosed with a tumour of the liver based on ultrasound and CT. MRI of the liver depicted a tumour growing from the chest wall towards the liver. Surgery revealed the rare entity of a malignant fibrous histiocytoma of the diaphragm.     

Fat-forming variant of solitary fibrous tumour of the pleura: CT findings

The fat-forming variant of solitary fibrous tumour (SFT) was previously called lipomatous haemangiopericytoma and is a rare variant of solitary fibrous tumour. It predominantly occurs in the deep soft tissues of the retroperitoneum and thigh. Only a handful of cases involving the perineum, spine, thoracic wall and pelvic cavity have been reported in the radiological literature and the fat-forming variant of SFT involving the pleura has not been previously reported. Herein, we report the CT findings of a case of the fat-forming variant of SFT involving the pleura that was treated by excision. Chest CT showed a large lobulated heterogeneous fatty mass with a multifocal enhancing soft-tissue component in the left lower hemithorax. Although rare, the fat-forming variant of SFT of the pleura should be added to the differential diagnosis of fat-containing pleural soft-tissue tumours.     

A giant malignant peripheral nerve sheath tumour of the breast: CT and pathological findings

Malignant peripheral nerve sheath tumour (MPNST) is a rare soft tissue sarcoma. In particular, primary MPNST of the breast is extremely rare. We report a case of a giant malignant peripheral nerve sheath tumour involving the entire right breast, which was not associated with neurofibromatosis type 1 (NF-1) or previous radiation therapy. A CT scan showed a huge heterogeneous soft tissue mass with well-enhanced nodules at its periphery and low-density internal necrosis, which was confirmed by modified radical mastectomy.     

Comparision between transrectal ultrasonography and computed tomography with rectal inflation of gas in preoperative staging of lower rectal cancer

Computed tomography with rectal air insufflation was compared with transrectal ultrasonography (TRUS) in 63 patients. The CT protocol involved pre- and postcontrast scans with 5 mm slice thickness following air insufflation in IV antiperistaltic agent. Of the patients, 79 % were scanned in the prone position. Results of the preoperative examinations were compared with the histological findings. The CT examination had an accuracy rate of 74 %, predicting perirectal spread with a sensitivity of 83 % and a specificity of 62 %, whereas the corresponding figures for TRUS were 83, 91 and 67 %. The accuracy, sensitivity and specificity of CT and TRUS for nodal involvement were 57, 56, 57, 66, 68 and 64 %-respectively. These findings confirm that TRUS is more accurate than CT in local tumour (T) staging and in detecting nodal (N) spread. However, the appropiate CT technique shows spread of tumour outside the rectal wall and locoregional lymph nodes with reasonable accuracy. Lymphatic spread correlated with nodal size. TRUS and CT correctly staged only 57 and 43 %, respectively, of cases with nodal metastases with maximum diameter of 5 mm. TRUS sometimes overstaged perirectal growth of tumour in 7 patients, due to inflammation (5 patients) or incorrect positioning of the ballon in relation to the tumour surface (2 patients). Received 11 April 1995; Revision received 22 January 1996; Accepted 24 January 1996     

Pedunculated malignant peripheral nerve-sheath tumour of the diaphragm presenting as recurrent lung infection: ultrasound diagnosis

We report a rare case of malignant peripheral nerve-sheath tumour of the diaphragm in a 12-year-old boy with neurofibromatosis presented clinically and radiographically as recurrent lung infection. Ultrasound revealed a pedunculated diaphragmatic tumour invading the posterior chest wall. This case highlights that this unusual tumour may limit diaphragmatic excursion leading to, and even being masked by, superimposed lung infection. In patients with neurofibromatosis, ultrasound is recommended when chest radiography shows a basal lung opacity.     

PET/CT appearance of desmoid tumour of the chest wall

Desmoid tumours are rare, poorly circumscribed tumours that have a firm consistency and, although benign, have a remarkable tendency to infiltrate into surrounding structures. Extra-abdominal desmoid tumours involve mainly the extremities or the chest wall and are usually managed by wide radical resection. Moreover, desmoid tumours involving the chest wall are locally aggressive tumours with a high recurrence rate. We report a case of a pathologically proven desmoid tumour of the chest wall in a patient with a history of bilateral breast cancer and oesophageal cancer. We discuss the imaging appearances of this tumour on positron emission tomography combined with computed tomography (PET/CT) and magnetic resonance imaging.Desmoid tumours are poorly circumscribed tumours that are firm, rubbery and have a remarkable tendency to infiltrate into surrounding structures with a strong propensity to recur locally after resection [1]. Desmoid tumours of the chest wall are uncommon tumours that have been described extensively in the pathological and surgical literature.¹⁸F-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography combined with computed tomography (FDG-PET/CT) has been shown to be very useful in the staging of patients with breast cancer and oesophageal cancer, as well as in the evaluation of treatment response [2]. It has a specific ability to discriminate responders from non-responders more accurately and earlier than conventional imaging methods [2]. PET/CT also plays an important role in the assessment of malignant soft-tissue tumours of the chest wall, such as sarcoma, by improving the accuracy of staging and helping to determine the appropriate therapy [3]. The PET/CT imaging characteristics of chest wall desmoid fibromatosis, a benign condition that may clinically mimic metastatic disease or sarcomatous degeneration, has not yet been reported to our knowledge.We describe the PET/CT and MRI appearances of a biopsy-proven desmoid tumour of the chest wall in a patient with a history of bilateral breast cancer and oesophageal cancer.     

Malignant pleural mesothelioma: the spectrum of manifestations on CT in 70 cases.

AIM: The aim of this pictorial review is to illustrate the spectrum of manifestations on computed tomography (CT) of malignant pleural mesothelioma. Malignant pleural mesothelioma is the most common primary neoplasm of the pleura, but nevertheless is a rare tumour. It has a strong association with previous occupational exposure to asbestos and has a bleak prognosis. MATERIALS AND METHODS: The pre-treatment CT findings of 70 patients at our institution, and the subsequent findings of the 35 patients who had follow-up CT, have been reviewed by three observers by consensus. 16 patients had surgical resections. RESULTS: The most common pre-treatment findings were pleural thickening (94%) and pleural effusions (76%). Both contraction (27%) and enlargement (10%) of the ipsilateral hemithorax were identified. Extension of disease to the chest wall, mediastinum, thoracic lymph nodes, and below the diaphragm were identified. Concurrent bilateral pleural calcification and plaques indicative of previous asbestos exposure were identified in 16% of patients. CT failed to identify chest wall and mediastinal invasion in a number of patients who underwent surgical resections. CONCLUSION: CT plays an important role in the diagnosis, assessment, and evaluation of treatment response of this tumour, although it has some limitations in specific areas in evaluating patients for surgical resection.     

Meningioangiomatosis: advanced imaging and pathological study of two cases

Meningioangiomatosis (MA) is a rare benign intracranial tumour of uncertain pathogenesis, with only 33 cases reported in the literature. Imaging features have been described in 21 cases, only 3 with contrast-enhanced MRI. We present two cases of MA with MRI and/or CT findings and gross, ultrastructural, and immunohistochemical characteristics. MRI is particularly helpful for establishing the origin of the lesion and its anatomical location, while CT shows calcification, if present. The pathological characteristics establish the diagnosis and underline the differences from other entities such as malignant meningioma, one of the most important differential diagnostic considerations.     

Radiologic findings in peripheral neurilemoma

Neurilemoma is a primary nerve sheath tumour that usually arises from a peripheral nerve. In a series of eight solitary neurilemomas four benign and four malignant tumours are observed. Three neoplasms are of intrathoracic origin, four tumours arise in the retroperitoneal space and one tumour develops in the duodenal wall. Radiographic findings using computed tomography, ultrasonography and arteriography are presented. All neurilemomas show relatively low density in CT compared with other parenchymal tumours. All benign and three of the malignant neurilemomas reveal good contrast enhancement. Arteriography has an important role in defining the tumour's blood supply and establishing the origin of the tumour. Five of six neurilemomas show hypervascularity in arteriography. Ultrasonography shows cystic degeneration in three malignant and in one benign neurilemoma. Pathologic correlation of peripheral neurilemoma is discussed by using a special immunoperoxidase technique.     

Incidental localized (solitary) mediastinal malignant mesothelioma

Primary mediastinal mesotheliomas are rare tumours. The mesothelial lining cells of the the pericardium are suggested as the most probable cells of origin. Most of these tumours appear either as a diffuse or nodular thickening of the pericardium that encase and even invade the heart. Localized mediastinal mesotheliomas are distinctly uncommon. We report the imaging findings of a solitary malignant mediastinal mesothelioma that presented mainly as a cystic anterior mediastinal mass. On chest radiography, the tumour appeared as a right paramediastinal soft tissue mass located adjacent to the right middle and lower lobes. On CT, a large, well-circumscribed, right anterior mediastinal mass with a central zone of fluid attenuation was observed. This mass had a thin, smooth wall of uniform thickness as well as a small component that demonstrated soft tissue attenuation. There was no plane of separation between the tumour and aorta/superior vena cava. At surgery the tumour could be dissected easily free from the pericardium and great vessels and it was removed totally. Histopathological examination of the tumour revealed a malignant epitheloid mesothelioma.     

Intracranial laterally based supratentorial neurenteric cyst

Neurenteric cysts are rare developmental cysts lined by endodermal derived epithelium. We present the case of a 68-year-old patient presenting with seizures who was found to have an extra-axial low density lesion with associated wall calcification on CT. Aspiration and biopsy of the cyst revealed a neurenteric cyst. Such lesions of the lateral supratentorial convexity are extremely rare and calcification has not been previously reported in these intracranial cysts.     

<Superscript>18</Superscript>F FDG PET/CT demonstration of IVC and right atrial involvement in adrenocortical carcinoma

Adrenocortical carcinoma is a rare and aggressive tumour. Inferior vena caval (IVC) involvement by the tumour thrombus is a rare phenomenon, and extension into the right atrium is even more rare. We describe a patient with Cushing’s syndrome for whom ¹⁸F-fluorodeoxyglucose (FDG) PET/CT showed FDG avid right adrenal mass with tumour extension to the IVC and right atrium.     

Case report: glomus tumour of the nasal cavity and paranasal sinuses

Glomus tumours are relatively rare in the head and neck. We present a glomus tumour of the nasal cavity and paranasal sinuses in a 55-year-old man and describe the CT appearances of this tumour and its histopathology. Received: 8 December 1997 Accepted: 22 December 1997     

Carcinosarcoma of the parotid gland: ultrasound and computed tomography findings

Carcinosarcoma is a rare tumour of the salivary gland. The ultrasound and CT appearances of a rapidly enlarging carcinosarcoma in the parotid are described. Both modalities revealed a 4-cm tumour with relatively benign features and no evidence of lymphadenopathy. Ultrasound showed a well-defined mass of homogeneous low echogenicity and posterior acoustic enhancement. Computed tomography showed a parotid mass of homogeneous attenuation similar to muscle, and homogeneous enhancement following contrast. The clue to the malignant nature of the lesion was a short indistinct superficial margin with tumour extension into the adjacent subcutaneous tissues.     

胃十二指肠平滑肌肿瘤的CT诊断

本文报导9例胃十二指肠平滑肌肿瘤,分析其CT表现与病理对照。CT检查补充了胃(肠)外型平滑肌肿瘤钡餐检查的不足,准确地显示出病变范围及有无其他器官的侵犯。胃外生型肿瘤可见肿块与胃壁有一段相连而胃外肿瘤则无。良恶性平滑肌肿瘤的CT表现有所不同。良性者肿块小,圆形、椭圆形或分叶状,密度均匀,静注造影剂后有均匀增强。恶性者肿块大,不规则分叶状,主要向腔外生长,常发生坏死,呈密度不均匀的低密度区,肿块与胃壁相连,对比增强后有边缘性增强。     

胰腺少见囊性病变的CT及MRI诊断

目的 探讨胰腺少见囊性肿瘤的影像学特征,提高诊断水平. 方法 回顾分析经手术病理证实的11例少见胰腺囊性肿瘤的临床特征及术前平扫和增强的CT、MRI表现,其中表皮样囊肿4例, 淋巴上皮囊肿4例,淋巴管瘤3例. 结果 (1)表皮样囊肿病变位于胰尾部,囊壁光滑完整,CT平扫囊性病变内的实质成分和脾的密度相同.CT和MRI增强后实质成分表现出和脾完全相同的强化方式.(2)淋巴上皮囊肿老年男性多见,病变呈现多房状境界清楚的肿块.CT平扫呈等密度,MRI T_1WI和T_2WI上混杂的等高信号,增强后囊壁分隔强化.(3)淋巴瘤表现为体尾部的分叶状多囊性病变,CT平扫密度略低于胰腺实质,MRI平扫呈长T_1长T_2信号.增强后分隔和囊壁轻度强化,肿瘤不与胰管交通,胰管轻度受压移位.结论胰腺少见的囊性病变具有一定的特征性的临床和影像学特征.     

Multiple imaging modalities in a case of hibernoma

Hibernoma is a rare hypervascular benign tumour that originate from brown fat. A case of hibernoma of the thigh, examined by xeroradiography, ultrasound, CT and angiography, is reported. The characteristics of this tumour are considered.