Purpose or Case Report:
Calcifying nested stromal epithelial tumor (CNSET) is a very rare primary liver tumor in children. To our knowledge, about 30 cases have been reported in literature. We describe the imaging appearance and histopathologic features of this tumor detected in a 2 year old girl who presented with an incidentally detected calcified liver lesion on a chest x-ray which was obtained for cough.
Computed tomography (CT) demonstrated a 5.5 centimeter sized heterogeneous mass with large coarse calcifications. MRI better demonstrated the margins of the lesion, which was predominantly hyper-intense on T2-weighted images. Large areas of signal void were seen in the superior aspect of the lesion, corresponding to the calcifications seen on CT. The lesion demonstrated restricted diffusion. Post-contrast, the lesion demonstrated enhancement in the portal venous phase with washout on the delayed phase. Initial diagnosis based on imaging findings and patient’s age was hepatoblastoma. However, serum alpha- fetoprotein (AFP) was normal, which is unusual with hepatoblastoma. Patient underwent subsequent wedge biopsy, which was proven to represent calcifying nested stromal epithelial tumor of the liver. PET/CT, obtained to evaluate for metastatic disease, demonstrated increased FDG activity within the primary hepatic lesion, with SUV Max of 3.5, with no evidence of FDG avid metastatic disease. She then underwent right hepatectomy and cholecystectomy.

No sign of tumor recurrence has been noted to date on the follow up abdominal ultrasound examination in the past 2.5 years.

Calcifying nested stromal epithelial tumor should be considered in the differential when a large heterogeneous liver tumor with coarse/ chunky calcifications is identified at imaging in the absence of elevated serum AFP in a child. Currently the standard treatment in complete surgical excision and liver transplantation if excision is not possible.
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