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Biomedical subjects

K S Song

Publications and source records attributed to K S Song.

105 records · Page 6Linked to original sources

Mediastinal tuberculous lymphadenitis: CT manifestations.

An analysis was done of computed tomographic (CT) scans of 23 Korean patients who had presented with a mediastinal or hilar mass on plain chest radiographs and had subsequently been found to have tuberculous lymphadenitis. Most patients were young adults. Findings of pulmonary tuberculosis were seen on plain radiographs in 14 patients. On CT, findings were of an overwhelming preponderance of involvement of the right paratracheal and tracheobronchial nodes. After injection of contrast medium, nodes larger than 2 cm in diameter invariably showed central areas of relative low density and peripheral rim enhancement. Enhanced walls were usually irregular in thickness. Some smaller nodes did not show low-density areas, but instead showed varying degrees of homogeneous enhancement. Although metastatic nodes can be of low density, experience in this study suggests that mediastinal lymphadenopathy in a young adult with the CT findings described above is characteristic enough to support a diagnosis of tuberculosis.

Adolescent↗

Anomalous insertion of the medial menisci.

Many types of meniscal anomalies have been reported. The authors encountered two cases of anomalous insertion of the anterior horn of the medial menisci to the lateral femoral condyle, which ran up along the course of the anterior cruciate ligament (ACL), but was independent of the ACL. These anomalies were noted during arthroscopic examination and surgery of the ipsilateral knee for a torn discoid meniscus and a patellar fracture. A 34-year-old woman had a horizontal tear of the lateral discoid meniscus. We performed arthroscopic partial meniscectomy of the inner torn portion of the lateral discoid meniscus and contoured it to resemble a normal meniscus. An anomalous insertion of the medial meniscus was found on examination of the joint during surgery. A 32-year-old man had a patellar fracture and we performed reduction under arthroscopy and internal fixation with cannulated screws. The same anomalous insertion of the medial meniscus was also found on examination of the joint during surgery. We report the cases with a review of the literature.

Adult↗

Cell death in retinoblastoma: electron microscopic, immunohistochemical, and DNA fragmentation studies.

Apparent cell loss by apoptosis occurs in carcinomatous tissue. To investigate cell death in retinoblastoma (Rb), ultrastructural examination, ApopTag staining, electrophoresis to detect apoptotic DNA fragmentation, and flow cytometric studies were performed. Immunostaining for the oncogenic products bcl-2 and p53 was also carried out. Relationships between the proliferation fraction (PF), apoptotic index (AI), and the distribution of bcl-2 and p53 were investigated according to the degree of histologic differentiation of Rb. Ultrastructurally, two patterns of cell death were seen. Necrotic cells exhibited vacuolation of cytoplasmic organelles with a marked lytic change in the karyoplasm and cytoplasm. In contrast, apoptotic cells were characterized by crescentic margination of chromatin, condensation of karyoplasm and cytoplasm, and fragmentation of the nucleus. Differentiated Rb had a low AI value (< 1%), whereas undifferentiated Rb had a high AI value (> 8%). The PF of undifferentiated RB (31%) was significantly higher than that of differentiated RB (14%). Analysis of DNA fragmentation using 3'-end labeling with terminal transferase indicated that undifferentiated Rb has increased DNA cleavage. The distribution of apoptotic bodies within Rb was inversely correlated with the expression of bcl-2. A majority of tumor cells of differentiated Rb were negative for p53, whereas 20-40% of tumor cells of undifferentiated Rb showed a positive reaction for p53. These findings suggest that the degree of susceptibility to apoptosis is closely related to PF, is inversely related to the degree of differentiation of Rb, and is protected by oncogene bcl-2.

Apoptosis↗

Spontaneous regression of osteochondromatosis of the radius after lengthening of the ulna: a case report.

Despite the high incidence, the natural biologic behavior of the osteochondroma is not yet known. In particular, the spontaneous regression of the exostosis is very rare and as yet an undefined phenomenon. Since the first description by Hunter in 1835, only 11 cases have been reported. On reviewing the reports in the literature, all cases were regressed spontaneously without significant mechanical stimuli such as surgical procedures. The reasons for the spontaneous regression were not explained sufficiently. This study describes one additional case of the spontaneous regression of osteochondromatosis of the radius and ulna after change of the mechanical strain or stress with lengthening of the ulna in a patient with multiple hereditary exostosis. The radiographic findings in this study are presented with some hypotheses explaining this interesting phenomenon.

Adolescent↗

Localized amyloidosis of the respiratory system: CT features.

PURPOSE: Amyloidosis includes a spectrum of diseases associated with an abnormal extracellular deposition of amyloid. The respiratory system is involved in approximately 50% of patients with amyloidosis. The purpose of this review is to present the CT findings of localized amyloidosis of the respiratory system. METHODS: We reviewed the CT findings of localized amyloidosis of the respiratory system from the previous reports and our experiences. RESULTS: Three patterns of involvement in respiratory system are presented: tracheobronchial nodular and diffuse parenchymal. CT demonstrates nodules, plaques, or diffuse thickening of the airways with calcification. Postobstructive collapse is associated in case of diffuse airway involvement. Parenchymal nodules have sharp and lobulated margins with peripheral or subpleural locations. High-resolution CT shows reticular opacities, interlobular septal thickening, and small, well-defined nodules of 2 to 4-mm in diameter predominantly in the subpleural regions. CONCLUSION: Amyloidosis of respiratory system has variable findings and CT scans clearly depict extent and distribution of the disease, its postobstructive pulmonary complication, and other associated findings such as calcification and lymphadenopathy.

Aged↗

Parietal pleura and extrapleural space in chronic tuberculous empyema: CT-pathologic correlation.

PURPOSE: The purpose of this work was to describe CT findings of the parietal pleura and extrapleural space in patients with chronic tuberculous empyema and to compare them with histopathologic findings following decortication. METHOD: Chest CT scans obtained from 13 patients with chronic tuberculous empyema who underwent decortication were retrospectively reviewed. All patients were men from 18 to 67 years old (mean 42 years old). CT findings of the parietal pleura and extrapleural space were correlated with histopathologic findings in all patients. RESULTS: Histopathologically, the enhanced parietal pleural peel on CT was fibrous collagenous tissue, and a low attenuated layer with 2 mm thickness within the parietal pleural peel (n = 2) was either a layer of histiocytes or caseation necrosis. The extrapleural space seen as an intermediate attenuation in six patients on CT was the proliferation of vessels, inflammatory cells, and granulomas in loose collagen background. The linear soft tissue attenuation interrupting the extrapleural fat (n = 5) on CT was a collagenous fibrous layer with proliferation of vessels and inflammatory cells. CONCLUSION: A layer of low attenuation in the parietal pleural peel may be due to different episodes of infection. The extrapleural space with intermediate attenuation may indicate ongoing inflammation. Linear soft tissue attenuation interrupting the extrapleural fat represents a fibrous layer rather than the subcostalis muscle.

Adolescent↗

Useful CT findings for predicting the progression of aortic intramural hematoma to overt aortic dissection.

PURPOSE: The purpose of this work was to assess useful CT findings for predicting the progression of aortic intramural hematoma to aortic dissection. METHOD: We analyzed the CT findings of 29 patients with aortic intramural hematoma with regard to the following: involved site, maximum thickness of hematoma, presence or absence of compression of true lumen, and pericardial and pleural effusion. CT findings were compared with those of the patients who progressed to aortic dissection (Group I) and those who did not (Group II). Each CT finding was evaluated with independent t test and Mann-Whitney U test (p < 0.05). RESULTS: Seven of 8 cases of Type A aortic intramural hematoma and 3 of 21 cases of Type B aortic intramural hematoma progressed to aortic dissection. The type of aortic intramural hematoma, maximum thickness of hematoma, compression of true lumen, and pericardial or pleural effusion were significantly different in Groups I and II. CONCLUSION: Type A aortic intramural hematoma, maximum thickness of hematoma, compression of true lumen, and pericardial or pleural effusion are the useful CT findings for predicting the progression of aortic intramural hematoma to aortic dissection.

Aged↗

Thoracic sequelae and complications of tuberculosis.

Pulmonary tuberculosis is caused by Mycobacterium tuberculosis when droplet nuclei laden with bacilli are inhaled. In accordance with the virulence of the organism and the defenses of the host, tuberculosis can occur in the lungs and in extrapulmonary organs. A variety of sequelae and complications can occur in the pulmonary and extrapulmonary portions of the thorax in treated or untreated patients. These can be categorized as follows: (a) parenchymal lesions, which include tuberculoma, thin-walled cavity, cicatrization, end-stage lung destruction, aspergilloma, and bronchogenic carcinoma; (b) airway lesions, which include bronchiectasis, tracheobronchial stenosis, and broncholithiasis; (c) vascular lesions, which include pulmonary or bronchial arteritis and thrombosis, bronchial artery dilatation, and Rasmussen aneurysm; (d) mediastinal lesions, which include lymph node calcification and extranodal extension, esophagomediastinal or esophagobronchial fistula, constrictive pericarditis, and fibrosing mediastinitis; (e) pleural lesions, which include chronic empyema, fibrothorax, bronchopleural fistula, and pneumothorax; and (f) chest wall lesions, which include rib tuberculosis, tuberculous spondylitis, and malignancy associated with chronic empyema. These varieties of radiologic manifestations can mimic other disease entities. Therefore, recognition and understanding of the radiologic manifestations of the thoracic sequelae and complications of tuberculosis are important to facilitate diagnosis.

Diagnosis, Differential↗

Stress fractures of the ribs in golfers.

During a collaborative review at three institutions, we documented 19 cases of stress fractures of the ribs in golfers. There were 13 men and 6 women with an average age of 39 years (range, 29 to 51). The 4th to 6th ribs were the most commonly injured. All fractures occurred along the posterolateral aspect of the ribs, and nine patients had fractures in more than one rib. Sixteen golfers sustained injury on the leading arm side of the trunk. Eighteen golfers were beginners, and the one experienced golfer had dramatically increased his practice time on the driving range before injury. Plain radiographs were usually diagnostic. However, bone scintigraphy was necessary to reach a diagnosis in three cases. A delay in diagnosis of 6 to 8 months occurred in two cases that were originally misdiagnosed as back strains. Stress fractures of the ribs in golfers may be more common than previously realized and may be incorrectly diagnosed as recalcitrant back strains. Based on the findings of other studies, we think fatigue of the serratus anterior is the mechanism of injury. We recommend strengthening the serratus anterior as rehabilitation after this injury and in a general conditioning program for golfers.

Adult↗

Focal fibrocartilaginous dysplasia of long bones: report of eight additional cases and literature review.

We report eight additional cases of focal fibrocartilaginous dysplasia (FFCD) in the proximal tibia (five), distal ulna (one), and distal femur (two). Spontaneous, complete resolution of the lesion was observed in two tibiae and one ulna. Three tibial lesions with genu varum deformity were managed with osteotomy. Two femoral FFCDs caused persistent or progressive deformity: one genu valgum with patellar dislocation, and one genu varum. These patients underwent concomitant deformity correction and lengthening by the Ilizarov method. The final results were satisfactory in all patients except one, who underwent valgus tibial osteotomy and developed mild postoperative genu valgum. The analysis of a total of 46 cases in the literature and our experience suggests that (a) FFCD has a wide histopathologic spectrum, ranging from purely dense, fibrous tendon-like tissue to benign fibrocartilaginous tissue; (b) at least 45% of tibial FFCD demonstrates progressive, spontaneous resolution; (c) in contrast, femoral and humeral FFCDs appear to have a slim possibility of spontaneous regression of the deformity; and (d) corrective osteotomy is indicated when the deformity is increasing or persistent, or when the existing deformity is severe enough to jeopardize adjacent joint mechanics and alignment.

Cartilage Diseases↗

Contiguous discitis and osteomyelitis in children.

Magnetic resonance imaging of 16 patients with contiguous discitis and osteomyelitis provided a specific diagnosis and defined the anatomic extent of vertebral and soft-tissue involvement. Altered signal changes were evident in the disc, adjacent vertebra in the end plate and metaphyseal equivalent regions, and the anterior prevertebral tissues. Significant posterior spread and disc herniation were not evident. Fourteen patients had lumbar involvement; two had cervical involvement. The patients were followed-up for an average of 4 years 5 months. Scoliosis has developed in one patient, and four continue to have a loss of lumbar lordosis. By comparing serial roentgenograms, the mean decrease of disc-space height after the acute episode was 43% (range, 51-61%). There was no restitution of normal disc-space height at the latest follow-up roentgenogram in any of the patients. A 14% (average) narrowing of the vertebral foramina was evident in seven cases. In one patient, a fusion progressively developed 7 years after the acute episode (before full skeletal maturity). However, several patients appear to be progressing toward fusion of adjacent vertebra. A study of histologic specimens elucidated vascular anatomy of the immature vertebra that further explain the disease characteristics.

Adolescent↗