Computed tomography of amyloidosis involving retroperitoneal lymph nodes mimicking lymphoma

A 74-year-old woman had multiple enlarged periaortic nodes with inhomogeneous enhancement on CT. Although a malignancy such as lymphoma was considered, amyloidosis involving retroperitoneal lymph nodes was confirmed on biopsy.     

Computed tomography enhancement characteristics of lymphomatous lymph nodes of the neck

OBJECTIVES: The objective of this study was to investigate prospectively CT contrast medium enhancement curves of lymphomatous lymph nodes of the neck. MATERIALS AND METHODS: Eleven patients with biopsy-proven lymphoma had their enlarged cervical lymph nodes examined with dynamic CT and compared with a control group. RESULTS: The mean contrast medium enhancement of the lymphomatous nodes was significantly lower than that of the control group in the time interval from 40 s to 180 s after injection. DISCUSSION: The enhancement pattern previously suggested from studies of retroperitoneal lymph nodes was confirmed in this prospective study of cervical nodes.     

Computed tomography of malignant lymphoma of the brain

Summary Correct diagnosis of malignant lymphoma of the brain and differentiation from malignant glioma, metastases, meningeoma and infection is often difficult. With the aim of finding characteristics pointing to the correct diagnosis all CT examinations from 16 patients with primary or secondary lymphoma of the brain were analysed. In 3 of 10 patients with primary lymphoma and 4 of 6 with secondary lymphoma the tumors were multiple. No differences between the CT appearance of primary and secondary lymphoma were found except that secondary lymphomas were generally smaller and more often multiple. The lymphomas were most often well demarcated, had a density equal to or slightly higher than normal brain tissue, were surrounded by no or slight edema and showed a moderate to marked contrast enhancement. The tumors were situated in the basal ganglia, corpus callosum or cerebellum in high frequency and were always in contact with either the ependyma of the ventricles or the superficial subarachnoid space. A tumor with widespread infiltration of the surroundings of the ventricles seen in 6 patients in the material is highly characteristic of lymphoma.     

Sonography of neck lymph nodes. Part II: abnormal lymph nodes

Assessment of cervical lymph nodes is essential for patients with head and neck carcinomas, and ultrasound is a useful imaging technique. Sonographic features that help distinguish between the causes of neck lymphadenopathy, including grey scale and Doppler features, are discussed. In addition to the distribution and location of nodes, the useful grey-scale features are: size, shape, internal architecture, intranodal necrosis, absence of hilar structure and calcification. The useful Doppler features are: distribution of vascularity and intranodal resistance. Ancillary features such as oedema of soft tissue and nodal matting are particularly helpful to identify tuberculous nodes.     

Sonography of neck lymph nodes. Part I: normal lymph nodes

Grey scale and power Doppler sonography play an important role in assessment of cervical lymphadenopathy. However, before examination of pathological nodes, a clear understanding of the anatomy of cervical nodes, scanning technique and sonographic appearances of normal cervical nodes is essential. This article reviews these topics in order to provide a baseline for sonographic examination of cervical lymphadenopathy.     

Computed tomography of malignant lymphoma involving the skull

The CT findings in two patients with the unusual presentation of malignant lymphoma in the skull are described. The dominant CT findings were contrast enhanced large soft tissue masses without calcifications on both sides of the bone with very little or no changes in the bone itself. This characteristic CT appearance may be helpful to differentiate primary lymphoma of the skull from other bone tumors and osteomyelitis.     

Computed tomography of the cervical lymph nodes: use of intravenous contrast enhancement

Intravenous contrast administration increases the sensitivity of computed tomographic scanning for enlarged cervical lymph nodes but requires a detailed knowledge of neck anatomy, especially in order to distinguish certain normal vessels from involved nodal groups. Along the collar chain, relations between the parotid and submandibular salivary glands and the posterior and anterior facial veins and facial artery are analyzed. The digastric muscle is defined as a transitional landmark between collar and deep cervical nodes. Along the deep cervical chain, emphasis is on the internal jugular vein, its variability in size, and its relations to the anterior scalene and omohyoid muscles.     

Computed tomography of mediastinal lymph nodes. Anatomic review based on contrast enhanced nodes following foot lymphography

Normal lymph nodes of the mediastinum are often not visible at CT. Some nodes may become contrast filled after foot lymphography, and these are easily seen in the CT sections. In the present report contrast filling is used to locate the main groups of mediastinal nodes at CT. The anatomy is reviewed and involvement of different nodes in various diseases is discussed.     

CT evaluation of cardiophrenic angle lymph nodes in patients with malignant lymphoma

Two hundred seventy-four computed tomographic (CT) scans of the thorax were obtained in 209 patients with malignant lymphoma (153 Hodgkin disease and 56 non-Hodgkin lymphoma). Fourteen patients (6.6%) were shown to have adenopathy involving the cardiophrenic angle lymph nodes on CT. Of these, only three were considered positive on the basis of chest radiography alone. The anatomy of these diaphragmatic lymph nodes and CT appearance of these nodes when pathologically enlarged are discussed.     

颈部恶性淋巴结的多层螺旋CT灌注研究

目的　分析颈部不同病理类型恶性淋巴结的动态强化特点和CT灌注参数 ,探讨其在颈部肿瘤中的鉴别诊断价值。方法　对 5 0例颈部间隙肿瘤患者行CT动态扫描 ,盲法分析不同病理类型的 33例恶性淋巴结的时间密度曲线特点和灌注参数 ,比较它们在时间密度曲线和灌注参数方面差异。结果　恶性淋巴结的血流量 (BF)值、血容量 (BV)值和表面通透性 (PS)值高于正常组织 (P <0 0 5 ) ,MTT值短于正常组织 (P <0 0 5 )。鳞癌、甲状腺癌转移淋巴结和淋巴瘤的峰值、强化值、BF值和BV值不同 (P <0 0 5 )。峰值时间、MTT值和PS值方面 ,三者有差异 ,但差异无显著性意义 (P >0 0 5 )。结论　颈部恶性淋巴结与正常组织以及不同病理类型恶性淋巴结的灌注特点不同 ,BF值、BV值、MTT值和PS值有助于恶性淋巴结与正常组织鉴别 ,峰值、强化值、BF值和BV值可帮助鉴别不同病理类型的恶性淋巴结。     

Improving specificity of computed tomography in diagnosis of malignant mediastinal lymph nodes

Four parameters of lymph node appearance on computed tomography were studied to improve specificity for malignancy in bronchogenic carcinoma: 1) node location, 2) homogeneity, 3) border definition, and 4) delineation by fat. Of 54 carcinoma patients, nodes were pathologically malignant in 21. Computed tomography showed enlarged nodes (over 1 cm) in 20 of these (true-positive rate, 96%), but also in 13 of the 33 patients with pathologically benign lymph nodes (false-positive rate, 39%). A combination of all four computed tomography parameters reduced the false-positive rate from 39 to 21% and decreased the true-positive rate from 96 to 86%. The criterion of border definition alone reduced the false-positive rate from 39 to 6%, but decreased the true-positive rate from 96 to 61%. The most useful computed tomography parameter was delineation, which reduced the false-positive rate to 15% and decreased the true-positive rate only to 86%. The computed tomography appearance of enlarged lymph nodes may be used to improve selection of patients with enlarged nodes for preoperative biopsy.     

Computed tomography of gastrointestinal lymphoma

From 275 computed tomographic (CT) examinations with positive findings of abdominal lymphoma, 26 patients were found to have gastrointestinal involvement by the disease. The stomach was most commonly involved, followed by small bowel, colon, and duodenum. CT was found to be accurate in detecting wall thickening and complications such as perforation and fistulization. False-negative examinations occurred in two patients with small submucosal gastric deposits ("bull's-eye" lesions). False-positive examinations were seen in two patients with hypertrophic gastritis. The CT manifestations of gastrointestinal lymphoma, correlated with the barium study appearance, are the subject of this report.     

Computed tomography of renal lymphoma

The CT studies of 29 patients with renal or perirenal lymphoma were retrospectively reviewed. Four patterns of disease were identified. Seventeen of 29 patients (59%) had bilateral renal masses. Only seven of these patients had associated enlarged retroperitoneal lymph nodes. Eight patients (28%) had single renal or perirenal lesions adjacent to or contiguous with bulky retroperitoneal lymphadenopathy. Three patients had infiltration of the perirenal space without significant renal parenchymal involvement, and one patient had a solitary renal mass. No patients in this series had diffuse involvement of the kidney without a focal mass. Renal involvement with lymphoma should be considered in any patient who develops multiple homogeneous solid renal or perirenal masses, even in the absence of other retroperitoneal disease.     

Computed tomography of rectal lymphoma

We present two human immunodeficiency virus positive patients with rectal lymphoma who on CT both demonstrated similar appearances of the rectal tumour, consisting of concentric thickening of the rectal wall and thickening of the levator ani muscles.     

Computed tomography and ultrasonography of metastatic cervical lymph nodes in oral squamous cell carcinoma

OBJECTIVES: To define criteria for CT and US in differentiating cervical lymph node metastases in oral squamous cell carcinoma (SCC). MATERIALS AND METHODS: CT and/or US of 230 metastatic lymph nodes and 228 benign lymph nodes in 147 patients with oral SCC were retrospectively evaluated. The CT and US findings of each lymph node were compared with the histopathological findings. A metastasis was defined on CT as a lymph node with rim or heterogeneous enhancement, or measuring 10 mm or more in the short axis, regardless of enhancement pattern, and on US as having definite internal echoes, regardless of size, or without definite internal or hilar echoes, but measuring 10 mm or more in the short axis. A lymph node with hilar echoes or a ratio of the long to short axis (L/S ratio) of 3.5 or more was considered benign. A lymph node failing to comform to any of these categories was termed questionable. RESULTS: The positive predictive value (PPV) for CT was 90.8% and the negative predictive value (NPV) was 70.4%. However, 65.7% of all lymph nodes could not be classified as either metastastic or benign. PPV for US was 96.5% and NPV was 88.1%. 25.5% of all lymph nodes could not be classified as either metastatic or benign. CONCLUSIONS: Despite limitations in detecting metastases, by including a third category 'questionable' our criteria appear clinically more useful than other current methods based on two groups only.     

Segmentation of neck lymph nodes in CT datasets with stable 3D mass-spring models segmentation of neck lymph nodes

RATIONALE AND OBJECTIVES: The quantitative assessment of neck lymph nodes in the context of malignant tumors requires an efficient segmentation technique for lymph nodes in tomographic three-dimensional (3D) datasets. We present a stable 3D mass-spring model for lymph node segmentation in computed tomography (CT) datasets. MATERIALS AND METHODS: For the first time our model concurrently represents the characteristic gray value range, directed contour information, and shape knowledge, which leads to a robust and efficient segmentation process. RESULTS: Our model design and the segmentation accuracy were both evaluated with 40 lymph nodes from five clinical CT datasets containing malignant tumors of the neck. CONCLUSION: The segmentation accuracy proved to be comparable to that of manual segmentations by experienced users and significantly reduced the time and interaction needed for the lymph node segmentation.     

Intrapulmonary lymph nodes: computed tomography findings with histopathologic correlations

We retrospectively assessed the computed tomography (CT) features of 31 intrapulmonary lymph nodes (IPLNs) with histopathologic correlations. CT scans revealed that the IPLNs are located in the subpleural region, frequently below the level of the carina, and angular in shape. Most of the IPLNs are solid in texture but occasionally present with a ground-glass appearance. For pleura-attached and pleura-separated IPLNs, one or more and 3 or more linear opacities extending from the nodules can be identified, respectively. Histologically, the IPLNs are located either at the junction of the pleura and lung lobules or at the junction of adjacent lung lobules.     

Computed tomography findings of ovarian metastases from colon cancer: comparison with primary malignant ovarian tumors

OBJECTIVE: The computed tomography (CT) findings of ovarian metastases from colon cancer were evaluated and were compared with those of primary malignant ovarian tumors. METHODS: Sixteen patients with 21 masses from colon cancer and 20 patients with 31 primary malignant ovarian tumors were included in this study. The CT findings (laterality, size, margin, shape, mass characteristic, strong enhancement of cyst wall, enhancement of solid portion, amount of ascites, peritoneal seeding, lymph node enlargement, and metastasis) and ages of the patients in both groups were compared. Univariate analysis, the Pearson chi test, and the independent-samples t test were used to distinguish them. RESULTS: A smooth margin of the tumor (odds ratio=24.3, 95% confidence interval: 2.9-204.2) and cystic nature of the mass (Pearson chi=12.96, P=0.005) were strong predictors of ovarian metastasis from colon cancer. CONCLUSION: Ovarian metastases from colon cancer show a smooth margin and more cystic nature on CT compared with primary malignant ovarian tumors.