Purpose or Case Report: To assess the size and number of pulmonary lesions in patients with hepatoblastoma
Diagnostic criteria of the PRETEXT (Pretreatment Extent of Disease) staging system for hepatoblastoma states that pulmonary lesions are judged to be metastases if there is one nodule greater than 10mm in diameter, or if among several nodules at least one is greater than 5mm in diameter.
Methods & Materials: Ten (14%) of 68 hepatoblastoma cases were selected from the radiology central reading system of the Japan Children’s Cancer Group’s (JCCG) liver tumor group for the period 2013–2016 (mean age: 4.3 years). Using a web-based radiology database, a retrospective review of initial chest CT images was conducted, focusing on largest diameter, number, and shape of pulmonary nodules, CT slice thickness, imaging evidence of PRETEXT stage and additional criteria scores.
Results: Nodule diameter ranged from 3 to 19mm (mean: 8.7mm). Four cases (40%) had small-sized lesions less than 5mm in diameter; therefore, these patients were categorized as no lung metastasis. The large lesion group included three patients diagnosed as PRETEXT stage IV, though no case of stage IV was found in the small lesion group. Additional criteria scores from the large lesion group were statistically higher than the small lesion group (p<0.01).
Conclusions: Using a criterion of 5mm in diameter is important when judging lung metastasis, otherwise metastasis might be overlooked.