A case of tricuspid valve infective endocarditis presenting with multiple nodular shadows in both lungs without known predisposing factors]

A 56-year-old woman was admitted to our hospital with fever, cough, and sputum production. Her chest radiograph and chest computed tomography showed multiple nodules. Laboratory findings revealed leukocytosis and an increased C-reactive protein concentration. Physical examination revealed a systolic murmur. Transesophageal echocardiography demonstrated a 1.5-cm area of vegetation on the tricuspid valve. Blood cultures grew Staphylococcus aureus. Tricuspid valve endocarditis and septic pulmonary embolism were diagnosed. She was treated successfully with intravenous ampicillin/sulbactam. This was a rare case of tricuspid valve infective endocarditis in an adult patient without known predisposing factors.     

A case of Ewing's sarcoma of the right femur associated with pulmonary metastases detected by fluorodeoxyglucose positron emission tomography

A 32-year-old man was referred to our hospital because of a nodular shadow on his chest x-ray film. Chest computed tomography scan revealed multiple nodules in both lungs. Video-assisted thoracoscopic surgery was performed to diagnose the tumor. Microscopic examination of the resected specimen showed tumor connecting of small round cells. Fluorodeoxyglucose positron emission tomography demonstrated strongly increased uptake in the right femur. Subsequently, magnetic resonance imaging showed a well defined mass, approximately 5cm in diameter, in the right lateral femur with isointensity on T1-weighted images and high intensity on T2-weighted images. A needle biopsy of the tumor of the right femur was performed. Pathological examination revealed the same findings of the pulmonary lesions. Immunohistochemical staining was positive for CD99 in the tumor cells. Ewing's sarcoma gene rearrangement was found using fluorescence in situ hybridization on frozen-section specimens. Based on these findings, a diagnosis of Ewing's sarcoma was made. The patient died 13 months after the initial detection of the disease despite intensive chemotherapy. In cases of multiple pulmonary nodular lesions in a young patient, metastatic tumors arising from bone soft tissue should be included in the differential diagnosis.     

A case of infective endocarditis accompanied with pulmonary complications in a drug addict]

A 21-year-old man who had a history of intravenous drug addiction was admitted with complaints of high fever and a productive cough. Chest CT on admission showed multiple consolidations, and pneumonia was initially diagnosed and treated. Because echocardiography after admission showed vegetation, with no bacteriological findings, attached to the tricuspid valve, right-sided infective endocarditis was diagnosed. After antibiotic therapy was changed, his fever was reduced and the inflammatory findings were eliminated. In the western world, most cases of right-side infective endocarditis are caused by drug addicts, but in Japan, this disease is very rare. Right-side infective endocarditis in drug addicts causes a high rate of pulmonary complications, in particular, septic pulmonary embolism. Many drug addicts suffering from pulmonary complications may consult doctors, but if the latter are not well-informed about this disease, it may not be possible to give an accurate diagnosis or proper treatment.     

Septic pulmonary embolism associated with periodontal disease: reports of two cases and review of the literature

We report two cases of septic pulmonary embolism associated with periodontitis. Chest CT revealed multiple nodular shadows with features characteristic of septic pulmonary embolism in both patients. Both patients had toothache, fever, and chest pain, and showed findings of periodontitis at initial presentation. Antimicrobial agents combined with dental surgery were successful in treatment. While septic pulmonary embolism from the lesions of periodontitis appears to be rare, periodontitis remains important in the differential diagnosis of septic pulmonary embolism.     

Intrathoracic neurofibroma originating in the left vagus nerve]

A 20-year-old man was admitted because of an abnormal mass shadow on chest X-ray film. Computed tomography (CT) and magnetic resonance imaging (MRI) disclosed a mass lesion in the superior portion of the left mediastinum. CT scans showed a well-defined mass with low density. Axial MRI rendered the mass lesion with intermediate signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The preoperative diagnosis was bronchogenic cyst. Video-assisted thoracic surgery revealed that the tumor originated in the truncus of the left vagus nerve. The resected tumor was 90 x 24 x 18 mm in size. The postoperative course was uneventful and hoarseness did not develop. The pathologic diagnosis was benign mediastinal neurofibroma without von Recklinghausen's disease. Such cases are extremely rare in the Japanese literature.     

Gorham's disease of the chest wall: CT and MR characteristics

We report a case of Gorham's disease of the chest wall in a 29-year-old man. A chest radiograph showed osteolysis of the left first, second, and third ribs. CT and MR images revealed a soft tissue mass around the affected ribs. The mass presented as having heterogeneous high signal intensity on T2-weighted MR images, and it showed minimal enhancement on contrast-enhanced MR images. A histologic specimen obtained by incisional biopsy from the left third rib revealed proliferation of lymphangiomatous tissue in the bone marrow. A diagnosis of Gorham's disease was made based on these clinical, radiologic, and histologic findings.     

Pulmonary embolism associated with a large tricuspid-related mass.

The case of a 43-year-old man with diabetes and alcoholism admitted to the emergency room with shock, fever, pleuritic chest pain and systemic symptoms is presented. Laboratory tests revealed anemia, leukocytosis, thrombocytopenia, high sedimentation rate and D-dimers, hypoxemia and hypocapnea. He also had sinus tachycardia, rSR' in V1 and an opacity on the periphery of the right pulmonary field. Blood and urine cultures were negative, as were serological markers. The echocardiogram showed a large mass adhering to the tricuspid valve, suggestive of myxoma. The patient underwent surgery, and anatomopathological examination of the mass showed it to be a bacterial vegetation, with no agent isolated. It is pointed out that differential diagnosis is difficult between a myxoma with systemic symptomatology associated with a possible pulmonary embolism, and tricuspid endocarditis with negative blood culture associated with a septic pulmonary embolism, which turned out to be the diagnosis in this patient.     

A case of primary leiomyosarcoma of the pulmonary artery]

A 74-year-old woman was admitted to our hospital because of right chest pain. The chest radiograph showed right hilar pulmonary artery dilatation. A mass exhibiting low intensity in T1-weighted images and high intensity in T2-weighted images was disclosed in the right pulmonary artery. Because of its clinical course and the MRI findings, the mass was thought to be tumorous tissue, and so pneumonectomy was performed. Leiomyosarcoma was diagnosed from the histological findings. Primary artery sarcoma is rare and the prognosis is considered to be extremely poor. The patient was successfully treated and had a good clinical outcome.     

MRI and CT in the differential diagnosis of pleural disease

STUDY OBJECTIVE: To explore the role of MRI in the differential diagnosis of pleural disease. PATIENTS: Forty-two patients with pleural disease were included. METHOD: Retrospective study. All patients were examined with both CT and MRI. The morphologic features of pleural lesions and magnetic resonance signal intensity on T1-weighted, T2-weighted, and contrast-enhanced T1-weighted images were evaluated. RESULTS: Mediastinal pleural involvement, circumferential pleural thickening, nodularity, irregularity of pleural contour, and infiltration of the chest wall and/or diaphragm were most suggestive of a malignant cause both on CT and MRI. Pleural calcification on CT was suggestive of a benign cause. Contrary to what has been previously reported in the literature, neither on CT nor on MRI, pleural thickness >1 cm revealed significant difference between malignant and benign pleural disease (p>0.05, chi(2) test). High signal intensity in relation to intercostal muscles on T2-weighted and/or contrast-enhanced T1-weighted images was significantly suggestive for a malignant disease. Using morphologic features in combination with the signal intensity features, MRI had a sensitivity of 100% and a specificity of 93% in the detection of pleural malignancy. CONCLUSION: When signal intensity and morphologic features are assessed, MRI is more useful and therefore superior to CT in differentiation of malignant from benign pleural disease.     

Mosaic pattern of encapsulated hepatocellular carcinoma: correlation of magnetic resonance imaging and pathology

Internal architecture of an encapsulated hepatocellular carcinoma (HCC) was studied with magnetic resonance imaging and histologic correlation. The capsule of HCC showed low intensity relative to liver on both T1- and T2-weighted images. The T1-weighted images were superior to the T2-weighted images in delineating the capsule of HCC. The tumor showed a mosaic pattern, which was a configuration composed of multiple compartments of different intensities, reflecting viable tumor nodules and a necrotic portion. Viable tumor nodules, composed of trabeculae of polygonal cells resembling the normal liver cell with well-formed sinusoids, showed low intensity relative to liver on T1-weighted images and high intensity on T2-weighted images. The necrotic portion, composed of coagulation of amorphous, thick eosinophilic material without hemorrhage or inflammatory reaction, showed low intensity relative to liver on both T1- and T2-weighted images. The T2-weighted images were superior to the T1-weighted images in demonstrating the mosaic pattern of HCC.     

Spontaneous pneumothorax as a complication of septic pulmonary embolism in an intravenous drug user: a case report

Infective endocarditis has been the major cause of morbidity and mortality among intravenous drug users (IDUs) with infections, mostly involving the tricuspid valve and presenting multiple septic pulmonary embolisms. Numerous pulmonary complications of septic pulmonary embolism have been described, but only a few have reported spontaneous pneumothorax. Our patient, a 23-year-old heroin addict, was hospitalized for tricuspid endocarditis and septic pulmonary embolism. Acute onset of respiratory distress occurred on his seventh hospital day and rapidly resulted in hypoxemia. Immediate bedside chest radiograph demonstrated left pneumothorax. It was thought to be a spontaneous pneumothorax, because he had not undergone any invasive procedure before the occurrence of pneumothorax. His clinical condition improved after the insertion of an intercostal chest tube. He later underwent surgery to replace the tricuspid valve as a result of the large size of the vegetation and poor control of infection. He ultimately survived. Pneumothorax is a possible lethal complication of septic pulmonary embolism in IDUs with right-sided endocarditis and should be considered in such patients when respiratory distress occurs acutely during their hospitalization.     

静脉应用毒品致脓毒性肺栓塞的临床特点与治疗

目的探讨静脉应用毒品致脓毒性肺栓塞（SPE）的临床特点和诊治经过，提高对该病的诊断和治疗水平。方法回顾性分析1994年1月至2006年12月收治的22例静脉应用毒品致脓毒性肺栓塞患者的临床表现、胸部影像学特点、血培养结果、超声心动图结果和诊治经过。结果临床表现为发热（22／22）、呼吸困难（20／22）、咳嗽（18／22）、胸痛（10／22）和咯血（8／22）。X线胸片和CT表现为结节（15／22）、局灶浸润影（12／22）、楔型阴影（5／22）、气囊（18／22）、空洞（11／22）及胸膜病变（11／22）。病灶分布在外周或胸膜下（20／22），CT较X线胸片可更清晰地显示病灶。血标本可培养出金黄色葡萄球菌（22／22）。超声心动图可见三尖瓣赘生物（22／22）。所有患者静脉使用2—4周耐酶青霉素、丁胺卡那霉素、万古霉素或左氧氟沙星，同时分别给予呼吸、循环支持和胸腔闭式引流。14例患者痊愈出院，8例好转出院。结论病情隐匿，缺乏特异性。高危人群如静脉吸毒者出现发热、影像学表现为多发和散在的胸膜下或周边气囊、结节影伴或不伴有空洞形成提示本病。早期诊断、及时给予抗生素治疗、控制肺外感染灶、给予呼吸支持，多数患者预后良好。     

A case of Morgagni's foramen hernia difficult to differentiate from lipoma]

A 61-year-old woman was admitted for chest discomfort. She had been admitted before, in March 1995, because of a lesion detected on chest roentgenograms. At that time, she was given a diagnosis of mediastinal lipoma based on the findings of chest computed tomography (CT) and magnetic resonance imaging (MRI), but was discharged without active intervention due to lack of subjective symptoms. During follow-up, the patient again reported chest discomfort beginning in March 1998. Because chest radiography disclosed. The tumor had enlarged, the patient was admitted to the hospital by our department. Chest MRI disclosed a mass with a signal intensity equal to that of subcutaneous fat in the pericardial space on both T1-weighted and T2-weighted images. Although sagittal images demonstrated continuity of the mass into intraperitoneal fat, a conclusive diagnosis of diaphragmatic hernia could not be made at that time. On April 30, 1998, a thoracotomy was performed on the basis of a preoperative diagnosis of mediastinal lipoma. During surgery, a hernial ring was observed slightly to the right and behind the sternum. The hernia consisted only of greater omentum, and was diagnosed as Morgagni's foramen hernia.     

Hepatic epithelioid hemangioendothelioma: MR imaging findings

We describe the sonographic, computed tomography and magnetic resonance imaging findings of two patients with histologically proven hepatic hemangioendothelioma. Both patients presented with multiple liver nodules. Color Doppler ultrasound demonstrated moderate vascularity at the periphery of the nodules, as well as central neovascularity. On enchanced computed tomography images, the lesions showed peripheral enhancement only. On magnetic resonance images, tumor signal was low on T1-weighted and moderately high on T2-weighted images. The distinction between normal liver and tumor was difficult on all sequences. Administration of superparamagnetic iron oxide particles delineated well the tumor by suppressing the signal of the normal liver and better depicted areas of remaining healthy parenchyma.     

Cystic lesion of the calcaneus. Intraosseous lipoma

We report two cases of intraosseous lipoma in the calcaneus of a 38 year old man, complaining about heel pain and a 27 year old woman with no pain. Plain radiographs showed a well-defined cystic lesion in the calcaneus with sclerotic margins. Computed tomography (CT) detected a well-defined, low-density lesion with attenuation values equal to adipose tissue. Magnetic resonance (MR) findings show similar signal intensity with subcutaneous adipose tissue on T1-weighted and T2-weighted images, and STIR-T2 imaging showing low signal intensity with complete suppression indicating the presence of normal fat. As a result, at first intraosseous lipomas could only be identified pathologically, but now it is easy to perform radiological diagnosis using MR.     

A case of thymic cyst with thymic hyperplasia]

A 70-year-old man was admitted to our hospital for treatment of an anterior mediastinal tumor. Although he was asymptomatic, an abnormal shadow was visible on chest radiography. CT revealed a heterogeneous tumor located in the anterior mediastinum. On MRI, the tumor demonstrated low signal intensity in T1-weighted images and high signal intensity in T2-weighted images. Laboratory data, including tumor markers, were mostly within the reference ranges. Although a CT-guided needle biopsy was performed, histologic diagnosis could not be confirmed. We resected the tumor with the thymus by median sternotomy. Histopathological examination demonstrated that the tumor was a multilocular thymic cyst with thymic hyperplasia and numerous lymphocytes. The lining epithelial cells gave positive reactions to immunohistochemical staining for carbohydrate antigen 19-9. Carcinoembryonic antigen and squamous cell carcinoma antigen levels in the cystic fluid were elevated. This case appeared to be an acquired thymic cyst with thymic hyperplasia. There are few reports of such cysts.     

Thoracic hemangiomas: imaging via CT, MR, and PET along with pathologic correlation

PURPOSE: To characterize the imaging features of thoracic hemangioma, including findings on computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) using 18F-fluoro-2-deoxy-D-glucose (FDG). METHODS: Six patients with thoracic wall hemangioma and 2 patients with mediastinal hemangioma were included in this study. Preoperative evaluation was performed using CT (n=7), MRI (n=8), and FDG-PET (n=2). Five cases were pathologically confirmed by surgery and the remaining 3 cases were diagnosed clinically. RESULTS: On CT, characteristic finding of phleboliths were depicted in 5 of 7 cases (71%). Fat component was demonstrated in 3 of 7 cases with CT (3/7-43%) and 5 of 8 cases with MRI (5/8-63%). On MRI, characteristic finding of high intensity on T2-weighted images was demonstrated in all 8 cases and the high signal intensity was emphasized in all 4 cases on fat-suppression T2-weighted images. Both of two PET scans showed mildly elevated accumulation of FDG. CONCLUSIONS: Phleboliths, fat component, and high intensity on T2-weighted and fat-suppression T2-weighted image were thought to be characteristic findings reflecting the histologic findings. It might be useful to recognize these findings for differentiating hemangiomas from other soft tissue tumors, particularly malignant neoplasms.     

Idiopathic Saccular Aneurysm of the Azygos Vein

A bstract Idiopathic saccular aneurysm of the azygos vein is a rare condition. We report the case of a 52-year-old man with saccular aneurysm of the azygos vein who underwent surgical resection. Preoperative dynamic computed tomography revealed strong and rapid enhancement of the chest mass. Magnetic resonance imaging showed a thoracic tumor with low signal intensity on the T1-weighted image and coexistence of low and high signal intensity on the T2-weighted image. lntraoperative findings showed cystic dilatation of the azygos vein. Although an accurate preoperative diagnosis of saccular azygos vein aneurysm is difficult, especially differential diagnosis between this anomaly and mediastinal tumors, a markedly enhanced mass shown by dynamic computed tomography was useful for the preoperative diagnosis of this anomaly.     

Bone cement cardiac and pulmonary embolism

This case describes a complication of bone cement use. A 65‐year‐old male patient with back spine trauma caused by a fall, underwent a percutaneous vertebroplasty. Five years later, he consulted for palpitations, and the electrocardiogram showed supraventricular arrhythmia. A transthoracic two‐dimensional echocardiography showed a hyperechogenic linear structure of 7 cm length, running from the lateral wall of the right ventricle to the right atrium through the tricuspid valve. This foreign body, which was suspicious for bone cement embolism, appeared rigid and was attached at the lateral wall of the right ventricle, with its proximal end free in the right atrium. The tip of the cement embolus was inside the myocardium of the lateral wall of the right ventricle, with risk of cardiac perforation. A fluoroscopy was performed, which confirmed the presence of cement within the right heart, with great mobility in each cardiac cycle. Chest computed tomography (CT) and multidetector CT three‐dimensional reconstruction confirmed the presence of cement within the right heart. Chest CT showed two pulmonary embolisms, one in the right upper lobe and one in the left lower pulmonary lobe. This case emphasizes the risk of late clinical manifestations of cardiac and pulmonary embolism of methylmethacrylate after percutaneous vertebroplasty, suggesting that the risk of such embolism might be underestimated. We propose routine chest radiography, two‐dimensional echocardiography, and chest CT after every percutaneous vertebroplasty, to detect asymptomatic cardiac and pulmonary embolism and thereby prevent serious delayed cardiopulmonary failures.     

A case of pulmonary actinomycosis with a unique finding in the chest MR image]

A 57-year old man, who was complaining of a productive cough and right shoulder pain, was admitted to our hospital because of an irregularly shaped mass located at rt. S1 on a chest radiograph. Bronchoscopy revealed no evidence suggesting lung cancer or any specific infection, either pathologically or microbiologically. CT-guided biopsy revealed changes resembling lymphocytic or plasmocytic interstitial pneumonitis with thickening of the alveolar septum and with accumulations of mononuclear cells and plasma cells, indicating the proliferation of bronchus-associated lymphoid tissue (BALT system). Since no definitive diagnosis was considered possible, a right upper lobectomy was performed. Histopathologic examination of tissue from the right upper lobe revealed sulfur granules and branching Gram-positive filamentous bacteria, and the condition was pathologically diagnosed as pulmonary actinomycosis. In the center of the mass lesion, the patient's chest MRI showed a very small area with a low signal intensity in T1- and a high signal in T2-weighted images, which suggested an accumulation of fluid in the actinomycotic abscess. As detailed MR findings in this condition have not been well described in the literature, the MRI evidence seen in this case may be useful for the diagnosis of actinomycosis.