Assessment of Lymph Node Metastases by Contrast-Enhanced MR Imaging in a Head and Neck Cancer Model

OBJECTIVE: We wanted to investigate the accuracy of contrast-enhanced MR imaging for the detection of lymph node metastases in a head and neck cancer rabbit model. MATERIALS AND METHODS: The metastatic lymph node model we used was created by inoculating VX2 tumors into the auricles of six New Zealand White rabbits. T1-weighted MR images were obtained before and after injecting gadopentetate dimeglumine at three weeks after tumor cell inoculation. The sizes, signal intensity ratios (i.e., the postcontrast signal intensities of the affected nodes relative to the adjacent muscle) and the enhancement patterns of 36 regional lymph nodes (parotid and caudal mandibular nodes) were evaluated on MR images and then compared with the histopathologic findings. RESULTS: No statistical difference was found between the sizes of 12 metastatic (10.5+/-3.2 mm) and 24 hyperplastic (8.0+/-3.6 mm) lymph nodes (p > 0.05). On the contrast-enhanced T1-weighted MR images, nine metastatic and four hyperplastic lymph nodes had peripheral high and central low signal intensity, whereas three metastatic and 20 hyperplastic lymph nodes had homogeneous high signal intensity. Using a signal intensity ratio less than one as a diagnostic criterion for a metastatic lymph node, the sensitivity, specificity and positive and negative predictive values of the enhanced MR images were 75% (9/12), 83% (20/24), 69% (9/13) and 87% (20/23), respectively, with areas under receiver-operating-characteristic curve values of 0.81. CONCLUSION: This experimental study confirms that metastatic and hyperplastic lymph nodes can be differentiated using MR images on the basis of the contrast uptake patterns, but that they cannot be differentiated using any particular size criteria.

Retroperitoneal Lymphangiomyoma in a Patient with Pulmonary Lymphangiomyomatosis: Case Report

Retroperitoneal lymphangiomyoma is rare abdominal finding of lymphangiomyomatosis (LAM). We report here on a case of retroperitoneal lymphangiomyoma and this is the first case that? been seen in the Korean literature. Retroperitoneal lymphangiomyoma associated with pulmonary LAM has rarely been reported in radiologic literature. The charateristic findings of this case are a prominent solid component and retroperitoneal lymphadenopathy mimicking a malignant tumor. A 45-year-old woman was admitted for further evaluation of a lower abdominal mass that could be palpated for 2 weeks. US findings showed relatively well-defined mass with septated cystic portions and echogenic solid portions in the lower abdomen. CT findings revealed a well-demarked retroperitoneal mass with septated cystic portions and enhancing solid portions at the right lower abdomen, and there were multiple retroperitoneal lymphadenopathy at the lower abdomen. The patient underwent a mass excision. The pathologic findings were retroperitoneal lymphangiomyoma with multiple lymph node involvement.

Imaging Findings of Castleman's Disease Localized in the Axilla: A Case Report

Castleman's disease is a rare benign lymphoproliferative disorder of uncertain origin which most commonly involves the mediastinum but rarely affects the axilla. We report a case of localized Castleman's disease involving the axillary lymph node. Mammography revealed a well-defined, homogeneously dense ovoid mass, 3 cm in size, in the left axilla, while gray-scale ultrasonography (US) demonstrated a well-defined, uniformly hypoechoic ovoid mass with good through transmission. Peripheral hypervascularity was observed at power Dopper US, and early rapid homogeneous enhancement at contrast-enhanced dynamic CT.

The Clinical Significance of Epitrochlear Lymphadenopathy on Elbow Radiographs in Rheumatoid Arthritis

PURPOSE: To evaluate the radiographic findings of epitrochlear lymphadenopathy with regard to the distribution and severity of the disease and clinal parameters in patients with rheumatoid arthritis. MATERIALS AND METHODS: Forty six patients with rheumatoid arthritis in whom epitrochlear oval-shaped densi-ties were seen on radiographs were involved in this study. There were 14 cases of unilateral epitrochlear lym-phadenopathy in which bilateral arthritic evidence was revealed by radiographs (mixed group), and 32 of bilat-eral lymphadenopathy in which there was arthritic evidence (positive group). Twenty-three patients in whom lymphadenopathy was not seen on radiographs of the elbow and who were diagnosed as suffering from rheumatoid arthritis functioned as controls (negative group). For scoring the degree of arthritis using the sim-plified scoring method proposed by Kaye et al., joints were divided into six groups, as follows: Joint 1, elbow; Joint 2, wrist; Joint 3, radial (1st and 2nd) PIP and MCP; Joint 4, ulnar (3rd, 4th, 5th) PIP and MCP; Joint 5, Joints 1+2+3+4; Joint 6, Joints 1+4. For each joint, scores were compared with those on the contralateral side in the mixed group. Differences in clinical parameters (disease duration, rheumatoid factor, ESR, and CRP), and scores for each joint in each arm were statistically compared between be positive and negative group. The number, mean diameter, and maximal diameter of epitrochlear lymph nodes were calculated and correlated with clinical parameters and scores for each joint. To evaluate the incidence of epitrochlear lym-phadenopathy without radiographic evidence of arthritis in 46 patients (78 arms) with lymphadenopathy, the frequency of cases in which the score for the joint was zero was assessed. RESULTS: In the mixed group, the mean score for Joint 6 of the arm with epitrochlear lymphadenopathy was significantly higher than that for the contralateral side in the mixed group (p = 0.022). Only CRP was signifi-cantly higher in the positive group than in the negative (p = 0.02). At joints 1, 2, 3, 5 and 6 of the left arm, and at joints 1, 4, 5 and 6 of the right arm, the mean score for each joint was significantly higher in the positive group than in the negative. Among 78 arms in which radiographs revealed epitrochlear lymphadenopathy, the score was zero for all joints in nine cases (11.6%). CONCLUSION: In patients with rheumatoid arthritis, evidence of epitrochlear lymphadenopathy, as seen on radi-ographs of the elbow, appears to be related to the distribution and severity of the disease and to CRP levels.

MR Findings of Cervical Lymphadenopathy: Tuberculosis Versus Metastasis

PURPOSE: To determine the MR findings of cervical lymphadenopathy which distinguish tuberculouslymphadenitis(TL) from metastatic lymphadenopathy(ML). MATERIALS AND METHODS: We retrospectively analyzed the MRfindings of 14 patients with TL and 19 with ML. Thirty-nine lesions in 14 patients with TL and 80 lesions in 19with ML were classified into three categories: conglomerate lesion (TL, 7; ML, 8); discrete lesion withoutnecrosis (TL, 3; ML, 15); and discrete lesion with necrosis (TL, 29; ML, 57). Between TL and ML, we compared age,sex, bilaterality, multiplicity, associated pulmonary tuberculosis, infiltration of adjacent fat, muscle, skin andsubcutaneous tissue, margin, and signal intensities on T1- and T2-weighted images. In discrete lesion, we alsocompared the minimal to maximal dimension ratio, and in discrete necrotic lesion, the thickness and evenness ofrim enhancement, and the location and extent of necrosis. RESULTS: There were statistically significantdifferences between TL and ML in age(34.7+/-13.1 years; 56.1+/-14.3 years), male to female ratio(3:11; 13:6),bilaterality(1/14; 10/19), multiplicity(5/14; 14/19), and associated active pulmonary tuberculosis(7/14; 1/19). OnT2-weighted images, TL showed predominantly homogeneous (30/39) or high (20/39) signal intensity, similar to thatof cerebrospinal fluid, but the signal inteusity of ML was predominantly heterogeneous(58/80), or lower than orsimilar to that of fat(41/80). Between TL and ML, however, there were no statistically significant differences ininfiltration of adjacent tissue, margin, signal intensity and its heterogeneity on T1-weighted image, minimal tomaximal dimension ratio, thickness and evenness of rim enhancement, or the location and extent of necrosis. CONCLUSION: In cervical lymphadenopathy, the existence of TL rather than ML is suggested by single or unilaterallesion in a young woman, by associated active pulmonary tuberculosis, or by homogeneous high signal intensity onT2-weighted MR images.

Radiologic Findings of lymphoproliferative Disorders of the Lung

Lymphoproliferative disorders of the lung consist of a spectrum of several entities from malignant lymphoma to variable non-lymphomatous lymphoproliferative disorders. While an entity may be histologically benign and can be cured without treatment or by surgical removal, malignancy may evolve, and aggressive treatment may thus be required. Radiographic and pathologic findings of an entity may overlap, but differential diagnosis of lymphoproliferative disorders of the lung is nonetheless important. In this paper we illustrate a variety of lymphoproliferative diseases of the lung that have been pathologically proven during the last ten years, and discuss their radiographic and pathologic characteristics.

An Unusual Manifestation of Pulmonary Lymphangiomyomatosis: Airspace Consolidation Masking Cystic Lung Lesions

We report a case of pulmonary LAM occurring in a 24-year-old pregnant woman in whom large areas of air-space consolidation partly masked interstitial lung disease on plain radiography. For correct dignosis, high resolutionCT was considered to still be a potent method for the disclosure of typical interstitial lung changes, including thin-walled cysts. Follow-up CT showed progressive worsening of these interstitial lung lesions.

Primary Amyloidosis Involving Mediastinal and Hilar Lymph Nodes: A Case Report

Amyloidosis is a rare systemic disease caused by extracellular accumulation of insolubel fibrillar material invarious tissues. The radiographic findings of amyloidosis involving the lymph nodes have not been previously reported in Korea, and we report a rare case of primary amyloidosis involving the mediastinal and hilar lymphnodes, with CT and radiographic appearances.