Accuracy of contrast-enhanced CT in liver neoplasms in children under 2 years age.

BACKGROUND: Multiple differentials exist for pediatric liver tumors under 2 years. Accurate imaging diagnosis may obviate the need for tissue sampling in most cases. OBJECTIVE: To evaluate the imaging features and diagnostic accuracy of computed tomography (CT) in liver tumors in children under 2 years. METHODS: Eighty-eight children under 2 years with treatment naive liver neoplasms and baseline contrast-enhanced CT were included in this institutional review board approved retrospective study. Two blinded onco-radiologists assessed these tumors in consensus. Findings assessed included enhancement pattern, lobulated appearance, cystic change, calcifications, central scar-like appearance, and metastases. The radiologists classified the lesion as hepatoblastoma, infantile hemangioma, mesenchymal hamartoma, rhabdoid tumor, or indeterminate, first based purely on imaging and then after alpha-fetoprotein (AFP) correlation. Multivariate analysis and methods of comparing means and frequencies were used for statistical analysis wherever applicable. Diagnostic accuracy, sensitivity, and positive predictive values were analyzed. RESULTS: The mean age of the sample was 11.4 months (95% CI, 10.9-11.8) with 50/88 (57%) boys. The study included 72 hepatoblastomas, 6 hemangiomas, 4 mesenchymal hamartomas, and 6 rhabdoid tumors. Presence of calcifications, multilobular pattern of arterial enhancement, lobulated morphology, and central scar-like appearance was significantly associated with hepatoblastomas (P-value < 0.05). Fourteen out of eighty-eight lesions were called indeterminate based on imaging alone; six lesions remained indeterminate after AFP correlation. Pure radiology-based diagnostic accuracy was 81.8% (95% CI, 72.2-89.2%), which increased to 92.1% (95% CI, 84.3-96.7%) (P-value > 0.05) after AFP correlation, with one hepatoblastoma misdiagnosed as a rhabdoid tumor. If indeterminate lesions were excluded for biopsy, the accuracy would be 98.8% (95% CI, 93.4-99.9%). CONCLUSION: CT had high accuracy for diagnosing liver neoplasms in the under 2-year age population after AFP correlation. Certain imaging features were significantly associated with the diagnosis of hepatoblastoma. A policy of biopsying only indeterminate lesions after CT and AFP correlation would avoid sampling in the majority of patients.

Intracranial extraosseous dural-based Ewing's sarcoma with fluid-haematocrit levels: imaging findings of a rare tumour.

Extraosseous dural-based primary Ewing's sarcoma of the central nervous system is a rare tumour posing a diagnostic challenge. On cross-sectional radiological imaging, the lesion has an extra-axial location with heterogeneous appearance. These lesions are usually multicystic with internal haemorrhage causing fluid-haematocrit levels. It mimics conditions like an aneurysmal bone cyst, microcystic meningioma, telangiectatic osteosarcoma or cystic metastasis. Exclusion of primary Ewing's sarcoma or malignancy elsewhere in the body is required to rule out a secondary. Surgery along with adjuvant chemotherapy and focal radiotherapy is the preferred mode of treatment. Due to the presence of non-specific small round blue cells on H&E stain, these tumours are also confused with lymphoma, osteosarcoma, rhabdomyosarcoma, Merkel cell carcinoma, ependymoblastoma and neuroendocrine carcinoma. Immunohistochemistry provides a definitive diagnosis. A high degree of suspicion in the preoperative scans is crucial for prognostication and early management of this aggressive tumour leading to improved patient survival.