ABSTRACT
ABSTRACT: Ewing sarcoma is the second most common osseous malignancy in pediatric patient. Metastasis is common due to its aggressive nature, with 25% of patients with metastasis at diagnosis, commonly to the lungs, bone, or bone marrow. Muscle metastasis is uncommon. We report FDG PET/CT findings of multifocal muscle metastases of recurrent Ewing sarcoma in the extremities without lung and bone involvement in a 6-year-old boy.
Subject(s)
Fluorodeoxyglucose F18 , Muscle Neoplasms , Positron Emission Tomography Computed Tomography , Sarcoma, Ewing , Tomography, X-Ray Computed , Humans , Sarcoma, Ewing/diagnostic imaging , Sarcoma, Ewing/pathology , Male , Child , Muscle Neoplasms/diagnostic imaging , Muscle Neoplasms/secondary , Extremities/diagnostic imaging , Recurrence , Multimodal Imaging , Bone Neoplasms/diagnostic imaging , Bone Neoplasms/secondaryABSTRACT
ABSTRACT: A 12-year-old girl presented with a history of kidney transplant complicated by posttransplant lymphoproliferative disease. A solid mass was found in the lower pole of the transplanted kidney, concerning for posttransplant lymphoproliferative disease. However, biopsy confirmed papillary renal cell carcinoma. FDG PET/CT showed increased activity in the known renal cell carcinoma in the renal allograft.
Subject(s)
Carcinoma, Renal Cell , Kidney Neoplasms , Kidney Transplantation , Lymphoproliferative Disorders , Female , Humans , Child , Carcinoma, Renal Cell/complications , Kidney Transplantation/adverse effects , Positron Emission Tomography Computed Tomography/adverse effects , Fluorodeoxyglucose F18 , Kidney , Kidney Neoplasms/complications , Lymphoproliferative Disorders/etiologyABSTRACT
BACKGROUND: Renal artery stenosis is an important cause of hypertension in children, accounting for 5-10% of cases. When suspected, noninvasive imaging options include ultrasound (US), computed tomography (CT) angiography and magnetic resonance (MR) angiography. However, digital subtraction angiography (DSA) remains the gold standard. OBJECTIVE: To investigate the accuracy and inter-reader reliability of CT angiography in children with suspected renal artery stenosis. MATERIALS AND METHODS: This is a retrospective study of patients suspected of having renal artery stenosis evaluated by both CT angiography and DSA between 2008 and 2019 at a tertiary pediatric hospital. Only children who underwent CT angiography within 6 months before DSA were included. CT angiography studies were individually reviewed by two pediatric radiologists, blinded to clinical data, other studies and each other's evaluation, to determine the presence of stenosis at the main renal artery and 2nd- and 3rd-order branches. The sensitivity, specificity and accuracy were calculated using DSA as the reference. The effective radiation dose for CT angiography and DSA was also calculated. Kappa statistics were used to assess inter-reader agreement. RESULTS: Seventy-four renal units were evaluated (18 girls, 19 boys). The patients' median age was 8 years (range: 1-21 years). Overall, CT angiography was effective in detecting renal artery stenosis with a sensitivity of 85.7%, specificity of 91.5% and accuracy of 88.9%. There was moderate inter-reader agreement at the main renal artery level (k=0.73) and almost perfect inter-reader agreement at the 2nd/3rd order (k=0.98). However, the sensitivity at the 2nd- and 3rd-order level was lower (14.3%). CT angiography provided excellent negative predictive value for evaluating renal artery stenosis at the main renal artery level (90.1%) and at the 2nd- or 3rd-order branches (82.7%). The median effective dose of CT angiography studies was 2.2 mSv (range: 0.6-6.3) while the effective dose of DSA was 13.7 mSv. CONCLUSION: CT angiography has high sensitivity and specificity at the main renal artery level with a lower radiation dose than previously assumed. Therefore, it can be used as a diagnostic tool in patients with low to medium risk of renal artery stenosis, and as a screening and treatment planning tool in patients at high risk.
