Pediatric Liver Masses: Radiologic-Pathologic Correlation Part 1. Benign Tumors

Abstract

Benign hepatic tumors in children include lesions that are unique to the pediatric age group and others that are more common in adults. Infantile hemangioendothelioma, or infantile hepatic hemangioma, is a benign vascular tumor that may cause serious clinical complications. It is composed of vascular channels lined by endothelial cells. At imaging, large feeding arteries and draining veins and early, intense, peripheral nodular enhancement with centripetal filling on delayed images are characteristic features. Mesenchymal hamartoma of the liver occurs in young children and is characterized pathologically by mesenchymal proliferation with fluid-containing cysts of varying size and number. The mesenchymal component or cystic component may predominate; this predominance determines the imaging appearance of the tumor. Benign epithelial tumors that are common in adults may infrequently occur in childhood. These include focal nodular hyperplasia (FNH), hepatocellular adenoma, and nodular regenerative hyperplasia. All are composed of hyperplastic hepatocytes similar to surrounding liver parenchyma and may be difficult to discern at imaging. Preferential hepatic arterial phase enhancement helps distinguish FNH and hepatic adenoma from uninvolved liver. Hepatic adenoma often has intracellular fat and a propensity for intratumoral hemorrhage, neither of which are seen in FNH. Unlike adenoma, FNH often contains enough Kupffer cells to show uptake at sulfur colloid scintigraphy. Nodular regenerative hyperplasia is often associated with portal hypertension, which may be evident at imaging. Knowledge of how the pathologic features of these tumors affect their imaging appearances helps radiologists offer an appropriate differential diagnosis and management plan.

Infantile Choriocarcinoma of the Liver: Case Report and Review of the Literature

“…The most common neoplasm involving the liver in children is metastasis most common primary liver neoplasms in children are malignant, about one-third are benign and may be of mesenchymal or epithelial origin [9].…”

“…Frequently the tumor is misdiagnosed as hemangioendothelioma, mesenchymal hamartoma, hepatoblastoma, metastatic neuroblastoma and undifferentiated sarcoma [9].…”

“…When compared to uterine choriocarcinoma, the imaging features are similar except that uterine choriocarcinoma tend to be infiltrative rather than presenting with masses. Increased tracer uptake by the lesion or the metastatic deposits may also be seen on bone scans [9].…”

Role of Multidetector Computed Tomography in Evaluation of Pediatric Abdominal Tumors

“…6): They appear as well defined hypodense lesion showing early dense peripheral nodular enhancement with progressive centripetal fill in. (12,13) Infantile Hemangioendothelioma (Fig. 7): They appear as well defined homogeneous hypodense masses with calcifications in ~ 49% cases.…”

“…Clinically the patient may present with high output congestive heart failure. (13,14) Lymphomas: These are common lesions in pediatric age group, usually of Non-Hodgkin's variety. Multiple homogenously enhancing retroperitoneal lymph nodes forming conglomerate masses are usually seen.…”