Soo Ah Im

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.

Predisposing Factors of Posterior Reversible Encephalopathy Syndrome in Acute Childhood Leukemia

A retrospective chart review was performed on 19 patients aged <18 years who developed posterior reversible encephalopathy syndrome as a complication during treatment of acute childhood leukemia. Posterior reversible encephalopathy syndrome was most often observed during acute lymphoblastic leukemia induction chemotherapy (n = 9, 47.4%) and after hematopoietic stem cell transplantation (n = 8, 42.1%). Among eight patients with the complication of posterior reversible encephalopathy syndrome after hematopoietic stem cell transplantation, five (62.5%) had a history of hypertension. In contrast, among 11 patients with the complication of posterior reversible encephalopathy syndrome without hematopoietic stem cell transplantation, only one (9.1%) had a history of hypertension. Moreover, unlike other leukemia induction chemotherapy, posterior reversible encephalopathy syndrome developed only in patients who received acute lymphoblastic leukemia induction chemotherapy. Posterior reversible encephalopathy syndrome patients required long-term anticonvulsant therapy (n = 9, 50.0%) and manifested intractable seizures (n = 3, 16.7%). Sequelae were evident in long-term follow-up magnetic resonance images (n = 5, 26.3%). Acute lymphoblastic leukemia chemotherapy regimens apparently comprised the main predisposing factors for posterior reversible encephalopathy syndrome complicated during induction chemotherapy, compared with hypertension and immunosuppressive agents after hematopoietic stem cell transplantation.

Imaging Features of Metaplastic Carcinoma with Chondroid Differentiation of the Breast

OBJECTIVE The purpose of this study was to evaluate the imaging features--including the mammographic, sonographic, MRI, and bone scintigraphic findings--in 12 patients with metaplastic carcinoma with chondroid differentiation of the breast and to correlate the imaging findings with the pathologic features. CONCLUSION Metaplastic carcinoma with chondroid differentiation of the breast manifests as a palpable mass and should be included in the differential diagnosis of a large indistinct highdensity mass with amorphous or coarse calcifications on mammography and a relatively circumscribed complex echoic mass with posterior enhancement on sonography. A relatively circumscribed mass with a nonenhancing T2 intermediate- to high-signal-intensity internal component on MRI and an area of intense uptake of 99mTc methylene diphosphonate (MDP) on bone scintigraphy might be useful in suggesting the diagnosis of metaplastic carcinoma with chondroid differentiation.

Gastrointestinal Complications Following Hematopoietic Stem Cell Transplantation in Children

Gastrointestinal system involvement is one of the principal complications seen in the recipients of hematopoietic stem cell transplantation (HSCT), and it is also a major cause of morbidity and death in these patients. The major gastrointestinal complications include typhlitis (neutropenic enterocolitis), pseudomembranous enterocolitis, viral enteritis, graft-versus-host disease, benign pneumatosis intestinalis, intestinal thrombotic microangiopathy, and post-transplantation lymphoproliferative disease. As these patients present with nonspecific abdominal symptoms, evaluation with using such imaging modalities as ultrasonography and CT is essential in order to assess the extent of gastrointestinal involvement and to diagnose these complications. We present here a pictorial review of the imaging features and other factors involved in the diagnosis of these gastrointestinal complications in pediatric HSCT recipients.

Prevalence of pre-stroke low bone mineral density and vertebral fracture in first stroke patients.

PURPOSE After stroke, many factors contribute to the loss of bone mineral density (BMD) and fracture. Pre-stroke low BMD and vertebral fracture may pose a greater risk of fractures and further contribute to additional functional loss. The purposes of this study were to assess pre-stroke BMD and vertebral fracture in patients with first stroke. METHODS Forty-eight patients with first stroke events were included. To reflect pre-stroke BMD, the patients who underwent bone densitometry tests within 30 days from stroke onset were selected. BMD was checked at the lumbar spine and both femurs (total hip and femoral neck). Thoracic and lumbar spine X-rays were performed. RESULTS Of the 48 stroke patients, 21 (43.8%) had osteoporosis and 19 (39.6%) had osteopenia. X-ray evaluation showed that 12 (25.0%) had one or more lumbar or thoracic vertebral fractures and 8 (16.7%) had two or more vertebral fractures. Of the 12 patients who had one or more vertebral fractures, 4 (33.3%) were previously aware of the fact that they had a vertebral fracture. CONCLUSION Results showed a high prevalence of pre-stroke low BMD and vertebral fracture in patients experiencing first stroke. Bone loss progresses rapidly in the acute stages of stroke, and such a high prevalence of pre-stroke low BMD and vertebral fracture may pose a greater risk of fractures and further contribute to additional functional loss. Therefore, early screening and active management of osteoporosis from the acute stages of stroke is critical.

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.

MR Findings of the Osteofibrous Dysplasia

Objective The aim of this study was to describe MR findings of osteofibrous dysplasia. Materials and Methods MR images of 24 pathologically proven osteofibrous dysplasia cases were retrospectively analyzed for a signal intensity of the lesion, presence of intralesional fat signal, internal hypointense band, multilocular appearance, cortical expansion, intramedullary extension, cystic area, cortical breakage and extraosseous extension, abnormal signal from the adjacent bone marrow and soft tissue and patterns of contrast enhancement. Results All cases of osteofibrous dysplasia exhibited intermediate signal intensity on T1-weighted images. On T2-weighted images, 20 and 4 cases exhibited heterogeneously intermediate and high signal intensity, respectively. Intralesional fat was identified in 12% of the cases. Internal low-signal bands and multilocular appearance were observed in 91%. Cortical expansion was present in 58%. Intramedullary extension was present in all cases, and an entire intramedullary replacement was observed in 33%. Cortical breakage (n = 3) and extraosseous mass formation (n = 1) were observed in cases with pathologic fractures only. A cystic area was observed in one case. Among 21 cases without a pathologic fracture, abnormal signal intensity in the surrounding bone marrow and adjacent soft tissue was observed in 43% and 48%, respectively. All cases exhibited diffuse contrast enhancement. Conclusion Osteofibrous dysplasia exhibited diverse imaging features ranging from lesions confined to the cortex to more aggressive lesions with complete intramedullary involvement or perilesional marrow edema.

Clinical Features and Prognosis of Invasive Pulmonary Aspergillosis in Korean Children with Hematologic/Oncologic Diseases

Invasive pulmonary aspergillosis (IPA) is the most frequent form of invasive fungal diseases in immunocompromised patients. However, there are only a few studies on IPA in immunocompromised children in Korea. This study was designed to characterize IPA in Korean children with hematologic/oncologic diseases. Medical records of children with hematologic/oncologic diseases receiving antifungal therapy were reviewed. The enrolled children were divided into the IPA group (proven and probable IPA) and non-IPA group, and the clinical characteristics and prognosis were compared between the two groups. During the study period, 265 courses of antifungal therapy were administered to 166 children. Among them, two (0.8%) episodes of proven IPA, 35 (13.2%) of probable IPA, and 52 (19.6%) of possible IPA were diagnosed. More children in the IPA group suffered from neutropenia lasting for more than two weeks (51.4% vs. 21.9%, P<0.001) and showed halo signs on the chest computed tomography (78.4% vs. 40.7%, P<0.001) than in the non-IPA group. No other clinical factors showed significant differences between the two groups. Amphotericin B deoxycholate was administered as a first line antifungal agent in 33 (89.2%) IPA group episodes, and eventually voriconazole was administered in 27 (73.0%) episodes. Ten (27.0%) children in the IPA group died within 12 weeks of antifungal therapy. In conclusion, early use of chest computed tomography to identify halo signs in immunocompromised children who are expected to have prolonged neutropenia can be helpful for early diagnosis of IPA and improving prognosis of children with IPA. Graphical Abstract

Alveolar Soft Part Sarcoma Arising from the Kidney: Imaging and Clinical Features

Alveolar soft part sarcoma (ASPS) is an extremely rare malignant soft tissue sarcoma primarily affecting young patients. It usually occurs in the lower extremities, although it can occur in soft tissue anywhere in the body. However, to our knowledge, there has been no case of primary ASPS originating from the kidney in the literature. We herein present the imaging and clinical features of an ASPS which occurred in a 16-year-old male presented as a palpable mass in the left side of the abdomen.