Pediatric fibrolamellar hepatocellular carcinoma: case report and review of the literature.

BACKGROUND: A 13-year-old boy presented with acute abdominal pain in the right upper quadrant without previous trauma. Abdominal ultrasound (US) revealed a mass in the right liver lobe with free intraperitoneal fluid, suggestive for hemoperitoneum. Magnetic resonance imaging confirmed a subcapsular lesion (5.7 × 4.6 × 4.1 cm), suggestive for fibrolamellar hepatocellular carcinoma (FL-HCC). Positron emission tomography-computed tomography revealed mild to moderate fluorodeoxyglucose (FDG) avidity, with no other FDG avid lesions. Hepatic tumor markers were negative. CASE REPORT: An elective right hepatectomy with cholecystectomy and hilar lymph node resection was performed. RESULTS: Histology showed a central fibrous scar and confirmed a FL-HCC (pT1bN0M0). The resected lymph nodes were tumor-free. Treatment of FL-HCC should consist of complete tumor resection with concurrent lymph node resection +/- orthotopic liver transplantation. Long-term follow-up is advised. A follow-up interval of 3-4 months in the first 2 years after surgical resection can be justified as FL-HCC have a high recurrence rate of more than 50% within 10-33 months. CONCLUSIONS: Malignancy can be a rare cause of abdominal pain in pediatric patients. An abdominal US is essential to prevent misdiagnosis. Treatment of FL-HCC should consist of R0 tumor resection with concurrent lymphadenectomy +/- orthotopic liver transplantation.

Correlation Between Apparent Diffusion Coefficient Value on MRI and Histopathologic WHO Grades of Neuroendocrine Tumors.

BACKGROUND: The correlation of diffusion-weighted MRI and tumor aggressiveness has been established for different tumor types, which leads to the question if it could also apply for neuroendocrine tumors (NET). PURPOSE: To investigate the possible correlation between apparent diffusion coefficient (ADC) value on magnetic resonance imaging (MRI) and histopathologic WHO-grades of NET. MATERIAL AND METHODS: Electronic patient records from patients presented at the multidisciplinary neuro-endocrine tumor board between November 2017 and April 2019 were retrospectively reviewed. Patients with both available MR imaging (primary tumor or metastasis) and known WHO tumor grade were included (n = 47). Average and minimum ADC values (avgADC; minADC) were measured by drawing a freehand ROI excluding only the outermost border of the lesion. The largest axial size (primary tumor) or most clearly delineated lesion (metastasis) was used. RESULTS: Forty seven patients met the inclusion criteria (mean age 59 ± 12 SD; 24F/23M). Twenty one patients (45%) were diagnosed with WHO G1 tumor, 17 seventeen with G2 (36%) and nine with G3 (19%) tumor. Twenty eight primary tumors and 19 metastases were measured. A significant difference was found between low-grade (G1+G2) and high-grade (G3) tumors (Mann-Whitney; avgADC: p < 0,001; minADC: p = 0,001). There was a moderate negative correlation between WHO-grade and avgADC/minADC (Spearman; avgADC: -0,606; 95% CI [-0,773; -0,384]; minADC: -0,581; 95% CI [-0.759; -0.353]). CONCLUSION: Our data show a significant difference in both average and minimum ADC values on MRI between low and high grade NET. A moderate negative correlation was found between histopathologic WHO grade and ADC value.