Diagnosis of solid abdomino-pelvic tumours in children : A retrospective radiological study

Abstract: Problems and Aims: Solid abdomino-pelvic tumours (APTs) in children constitute a heterogeneous group of masses which may originate from the retroperitoneum, the abdominal or pelvic cavities or any adjacent structure. They have different histological features, growth patterns and prognoses.The aim of the present investigation was to study the potential of modern imaging to assess the location, size and type of tumour, the extent of the disease and, if possible, the tumour stage in order to provide information to guide therapy.Materials and Methods: Imaging was performed in 92 children and adolescents with a primary APT using conventional radiography, radionuclide scintigraphy, US, CT and MR imaging for pre-treatment assessment, US-guided biopsies were performed in 61 children: the results were analysed retrospectively for yield and complications.Results: In pelvic bone tumours, all imaging modalities contributed to the evaluation of the primary tumour. Conventional radiography and bone scintigraphy were necessary for an initial diagnosis and CT for further evaluation. MR imaging and/or dynamic contrast-enhanced CT were mandatory prior to surgical resection.In primary kidney tumours contrast-enhanced CT and non-enhanced MR imaging were equally accurate in determining the size and origin of the tumours but were inadequate in assessment of tumour staging. MR imaging findings varied somewhat between Wilms' tumours and non-Wilms' tumours.In solid pelvic tumours compartmental localization was equally assessed with CT and MR and, together with gender, was found to correlate with the type of tumour.In abdominal neuroplastoma, evaluation of the local disease was equally accurate with CT and MR imaging, while assessment of invasion and lymphadenopathy was not possible regardless of imaging modality. Metastatic disease needed imaging with CT, MR, scintigraphy and bone marrow aspiration for assessment. Staging accuracy improved if an increased number of imaging methods were used.Needle core biopsy provided significantly better results than fine needle aspiration biopsy without an increase in complications.Conclusions: Assessment of APT in children requires the use of several different yet complementary imaging modalities in defining location, extent and tissue characteristics of the tumour. The choice of imaging modality depends on history, clinical findings, presumed location and available techniques. Pre-treatment assessment with imaging constitutes the basis for presentation of a staging protocol.