Hyun Jin Park

Pilomatricomas in children: imaging characteristics with pathologic correlation

BackgroundAlthough pilomatricoma commonly occurs in children, there is still a poor understanding of the imaging characteristics of pilomatricoma and lack of agreement regarding its imaging findings and histopathologic features.ObjectivesTo characterize the radiologic appearance of pilomatricomas on US, CT, and MR and to correlate the imaging findings with histopathologic features.Materials and methodsThe imaging findings of 47 pilomatricomas on US (n = 17), CT (n = 31), and MR (n = 5) were retrospectively evaluated. Pathologic specimens of all cases were reviewed and compared with imaging findings.ResultsAll lesions were well-circumscribed, subcutaneous nodules with partial attachment to the overlying skin. On US, the lesions were mostly hyperechoic with posterior acoustic shadowing and hypoechoic rim. On CT, they appeared as enhancing soft-tissue masses with varying amounts of calcification. MR findings were internal reticulations and patchy areas on T2-weighted images and contrast-enhanced T1-weighted images, corresponding to edematous stroma on pathology. Peritumoral inflammatory changes and connective capsule on pathology were well correlated with imaging findings.ConclusionPilomatricoma should be considered when US or CT shows a well-defined hyperechoic or calcific nodule in subcutaneous fat attached to the skin in children. MR images may be helpful in diagnosis. Pathologic findings are well correlated with imaging findings.

CT Differentiation of Anthracofibrosis from Endobronchial Tuberculosis

OBJECTIVE The purpose of this study was to use CT to differentiate anthracofibrosis from endobronchial tuberculosis (TB), both of which are major causes of benign bronchostenosis. MATERIALS AND METHODS We retrospectively reviewed the clinical and CT findings of 49 patients with anthracofibrosis and 35 patients with endobronchial TB diagnosed on the basis of bronchoscopic, microbiologic, and pathologic findings. Forty-five patients with anthracofibrosis and 32 patients with endobronchial TB had bronchostenosis on CT and were enrolled in the analysis. Nine (20%) of 45 patients with anthracofibrosis had coexistent active TB (two, endobronchial TB; six, pulmonary TB; one, TB pleurisy), and 13 (29%) had pulmonary infections other than TB. Two patients with anthracofibrosis and coexistent endobronchial TB were excluded from the analysis. The CT findings were analyzed with emphasis on the pattern, distribution, and location of bronchostenosis and the number of pulmonary lobes involved. RESULTS Anthracofibrosis was more common than endobronchial TB among elderly patients (p < 0.05). Statistically significant findings on CT were the pattern of bronchostenosis, presence of main bronchus involvement, and number of pulmonary lobes involved (p < 0.05). Bronchostenosis with anthracofibrosis usually involves multiple lobar or segmental bronchi. The main bronchus, however, tends to be preserved in anthracofibrosis. Most cases of endobronchial TB involve one lobar bronchus and the ipsilateral main bronchus with contiguity in extent. CONCLUSION Anthracofibrosis can be differentiated from endobronchial TB on CT. Furthermore, CT is helpful in the diagnosis of anthracofibrosis before bronchoscopy is performed.

Typical and Atypical Manifestations of Intrathoracic Sarcoidosis

Sarcoidosis is a systemic disorder of unknown cause that is characterized by the presence of noncaseating granulomas. The radiological findings associated with sarcoidosis have been well described. The findings include symmetric, bilateral hilar and paratracheal lymphadenopathy, with or without concomitant parenchymal abnormalities (multiple small nodules in a peribronchovascular distribution along with irregular thickening of the interstitium). However, in 25% to 30% of cases, the radiological findings are atypical and unfamiliar to most radiologists, which cause difficulty for making a correct diagnosis. Many atypical forms of intrathoracic sarcoidosis have been described sporadically. We have collected cases with unusual radiological findings associated with pulmonary sarcoidosis (unilateral or asymmetric lymphadenopathy, necrosis or cavitation, large opacity, ground glass opacity, an airway abnormality and pleural involvement) and describe the typical forms of the disorder as well. The understanding of a wide range of the radiological manifestations of sarcoidosis will be very helpful for making a proper diagnosis.

Two cases of pulmonary paragonimiasis on FDG-PET CT imaging

Positron emission tomography (PET) using18F-fluorodeoxyglucose (FDG) is useful in cancer diagnosis owing to its sensitivity to the differences in glucose metabolic rate between benign and malignant diseases, especially in the lung. One pitfall in PET imaging of lung disease, however, is the overlap in metabolic rate of inflammatory and neoplastic entities. Paragonimiasis is a food-borne parasitic disease that causes the pulmonary and pleural inflammation. We present two cases of pulmonary paragonimiasis that showed high uptake suggestive of tumor on FDG-PET CT images, both confirmed on histopathology by visualization ofParagonimus westermani eggs in the involved tissues.

Early CT findings of tomotherapy-induced radiation pneumonitis after treatment of lung malignancy.

OBJECTIVE The objective of our study was to evaluate the early CT findings of tomotherapy-induced radiation pneumonitis. MATERIALS AND METHODS Tomotherapy was performed during the study period in 31 patients with peripheral pulmonary malignancies, 25 of whom underwent follow-up CT within the first 3 months after tomotherapy. These 25 patients, with a total of 77 target lesions, were enrolled for the analysis. We evaluated pulmonary toxicity by the Common Toxicity Criteria for Adverse Events (CTCAE) method and retrospectively analyzed the CT findings of radiation pneumonitis, focusing on the appearance (attenuation, shape, degree of fibrosis) and location (concentric vs eccentric, centrifugal vs centripetal) of radiation pneumonitis relative to the target lesions. RESULTS Radiation pneumonitis developed around 34 target lesions (34/77, 44%) in 13 patients (13/25, 52%) during the first 3 months after tomotherapy. Five patients needed steroid therapy (CTCAE grade 2, 5/25 [20%]) and the remaining eight patients required no additional treatment (CTCAE grade 0 or 1, 20/25 [80%]). In appearance, the common CT findings were irregular shape (18/34), ground-glass attenuation (19/34), and no or minimal fibrosis (33/34). The location of the radiation pneumonitis was eccentric (22/34) and centrifugal (19/34) relative to the target lesions. CONCLUSION Radiation pneumonitis commonly developed with minimal clinical findings within 3 months after tomotherapy. The CT findings were nonspecific: focal, irregular-shaped ground-glass opacities with minimal fibrosis. However, the location of the radiation pneumonitis tended not to correspond to the planned target volume and had a centrifugal distribution. In addition, the immediate area around the target tended to be spared.

Extranodal marginal zone lymphoma occurring along the trachea and central airway.

Extranodal marginal zone lymphoma is a low-grade B cell lymphoma that presents with an indolent clinicopathologic nature. Although this tumor can occur in various sites, including the gastrointestinal tract and lungs, it develops and spreads extremely rarely along the trachea and central airway. We report a case of extranodal lymphoma of mucosa-associated lymphoid tissue with tracheobronchial involvement. An 83-year-old woman presented with a cough and dyspnea. Bronchoscopic evaluation confirmed diffuse, multiple nodular lesions in both the trachea and large bronchi, and she was diagnosed with an extranodal marginal zone lymphoma of the tracheobronchial tree. After systemic chemotherapy, she survived for more than 18 months.

Pulmonary Changes of Pleural TB: Up-to-Date CT Imaging

BACKGROUND The objective of this study was to evaluate pulmonary abnormalities of pleural TB by CT scanning and to determine CT scan findings for the development of the paradoxical response (PR). METHODS CT scans were performed for 349 patients with pleural TB (between 2008 and 2013). We excluded 34 patients with coexisting pulmonary disease (n 5 13) or a totally collapsed lung (n 5 21). We analyzed CT scans focusing on pulmonary abnormalities such as the presence of consolidation, cavitation, interlobular septal thickening, and micronodules and their distribution. In addition, we recorded the development of PR during follow-up and statistically analyzed differences in clinical and CT scan findings between patients with and without PR. RESULTS A total of 270 of 315 patients (86%) had pulmonary abnormalities. Common CT scan findings were micronodules (n 5 209 [77%]), interlobular septal thickening (n 5 202 [75%]),and consolidation (n 5 120 [44%]). Cavitation was seen in 49 patients (18%). Among 209 with micronodules, the nodules were in the subpleural region (n 5 146 [70%]), peribronchovascular interstitium (n 5 113 [54%]), and centrilobular region (n 5 64 [31%]). PR occurred in 81 patients(26%), and patients with PR tended to be young, male, and without underlying disease ( P , .05 by t test, Pearson x 2 test). Subpleural micronodules were more common in patients with PR than in those without PR (Pearson x 2 , P 5 .025). CONCLUSIONS Pulmonary abnormalities are very common in pleural TB. Th e most common CT scan findings were micronodules in the subpleural and peribronchovascular interstitium and interlobular septal thickening, suggesting the lymphatic spread of TB. In addition, PR is not rare in patients with pleural TB, especially in young, previously healthy, male patients who show subpleural nodules on initial CT scans.

Myxoid chondrosarcoma of the sinonasal cavity in a child: a case report.

Chondrosarcomas are malignant tumors of cartilage that rarely involve the sinonasal region, and myxoid chondrosarcoma is a rare histologic variant of chondrosarcoma that usually occurs in the soft tissue of extremities. Although several case reports and results of small series of chondrosarcomas in the sinonasal region in children are available, myxoid type chondrosarcoma is extremely rare. We recently experienced a case of low grade myxoid chondrosarcoma involving the sinonasal cavity in a 10-year-old boy, and here we report its radiologic-pathologic findings. In this case, chondroid calcification on CT and septal and marginal enhancement on MRI suggested a chondrosarcoma. Whole body PET-CT demonstrated no definite metastatic lesion and a low peak standardized uptake value primary tumor. However, no definite distinguishing imaging features were observed that distinguished low grade myxoid chondrosarcoma from conventional chondrosarcoma.

Clinicoradiologic Evidence of Pulmonary Lymphatic Spread in Adult Patients With Tuberculosis

OBJECTIVE The purpose of this study is to evaluate the prevalence and clinicoradiologic characteristics of pulmonary tuberculosis with lymphatic involvement. MATERIALS AND METHODS A total of 126 adults with active tuberculosis who underwent CT were enrolled. A retrospective investigation of CT images focused on the presence of perilymphatic micronodules, as well as other CT features of active tuberculosis. We selected two groups of patients with micronodules according to distribution (perilymphatic vs centrilobular). We compared clinical and CT findings between the two groups. RESULTS Fifteen patients were excluded because of coexisting pulmonary disease. Among 111 patients, the prevalence of perilymphatic micronodules, galaxy or cluster signs, and interlobular septal thickening was 64 (58%), 18 (16%), and 30 (27%), respectively. Of 106 patients with micronodules, 37 and 40 were classified into the perilymphatic and centrilobular groups, respectively. Compared with the centrilobular group, the perilymphatic group had statistically significantly lower frequencies of positive acid-fast bacilli smears (32% vs 70%), consolidation (70% vs 98%), and cavitation (30% vs 60%). However, frequencies of interlobular septal thickening (41% vs 18%), galaxy or cluster signs (30% vs 0%), and pleural effusion (43% vs 20%) were statistically significantly higher in the perilymphatic group. CONCLUSION CT findings representing pulmonary perilymphatic involvement are relatively common in adults with tuberculosis. These findings may represent lymphatic spread of tuberculosis and provide an explanation for the unusual CT features of pulmonary tuberculosis mimicking sarcoidosis and the low detection of Mycobacterium tuberculosis in patients with micronodules.

Fluoroscopy-assisted thoracoscopic resection for small intrapulmonary lesions after preoperative computed tomography-guided localization using fragmented platinum microcoils.

BACKGROUND Preoperative localization is frequently necessary to perform thoracoscopic resection of a small and/or deeply located intrapulmonary lesion. We developed a new method that uses a fragmented platinum microcoil, and retrospectively evaluated the efficacy of our technique. METHODS Between January 2006 and May 2010, self-made microcoils (Easimarker) were used to localize total 32 lesions (21 solid nodules, and 11 ground glass opacities) in 30 patients. Computed tomography-guided localization was performed into, or just around the lesions. Localized lesions were resected using fluoroscopy-assisted thoracoscopic surgery (FATS), and the histopathologic diagnosis was confirmed. The accuracy and complications of the localization procedure, and operative results of FATS were observed. RESULTS Mean size and depth of all lesions were 11.8 ± 5.1 mm (range: 3 to 22) and 12.2 ± 7.1 mm (range: 2 to 30). CT-guided localizations were successfully performed in all lesions. Four minimal pneumothorax and one parenchymal hematoma related with localization procedure occurred. There were three repeated procedures, which resulted from pleural rebounding of the microcoils. There were two microcoil detecting failures due to intrathoracic displacement during FATS. All 32 resected lesions were histopathologically diagnosed. CONCLUSION CT-guided localization using the fragmented microcoil combined with FATS of small intrapulmonary lesions is a safe, effective, and a diagnostically accurate procedure.