Benign liver and biliary tract masses in infants and toddlers

An Unusual Case of Neonatal High-Output Heart Failure: Infantile Hepatic Hemangioma

BACKGROUND

Infantile hepatic hemangioma (IHH) is a rare but life-threatening disorder that must be considered in the newborn presenting with high-output heart failure (HF). IHH is a tumor comprised of large vascular beds, which require a significant increase in blood flow as the lesion grows. This, in turn, creates an undue burden on the cardiovascular system, leading to high-output HF and potentially, respiratory distress. Recent changes have been made in the classification of certain hepatic hemangiomas and their treatments.

CASE REPORT

A 10-day-old girl presented to the Emergency Department with increased respiratory effort and an episode of apnea and cyanosis. A chest x-ray study was obtained and showed cardiomegaly and pulmonary edema concerning for HF. The patient was promptly admitted to the pediatric intensive care unit, where advanced imaging was obtained revealing findings consistent with IHH. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: HF in an infant is a critical condition often requiring prompt intervention and rapid diagnosis of the correct etiology to save a life. IHH is an example of an extrathoracic etiology of pediatric HF that has undergone recent changes in terminology and diagnosis. Increased awareness among emergency physicians of this disease process and its treatments can lead to expeditious diagnosis and treatment of this potentially life-threatening illness.

Space Occupying Lesions in the Liver

Space occupying liver lesions usually present with abdominal pain or abnormal physical findings, such as a palpable abdominal mass or distention. Liver lesions identified in children include benign and malignant neoplasms, inflammatory masses, cysts and metastatic lesions. Two-thirds of liver lesions in children are malignant. Hepatoblastoma accounts for two-thirds of malignant liver tumors in children. Benign lesions of the liver in children include vascular lesions, hamartomas, adenomas, and focal nodular hyperplasia. Although benign and malignant liver masses share some clinical manifestations, however treatment and prognosis differ. Evaluation involves physical examination, imaging evaluation and laboratory investigations such as serological markers [alpha-fetoprotein (AFP)] for malignant liver lesions. Ultrasound is the initial imaging modality of choice because it can detect, characterize, and provide the extent of liver lesions. However, CT or MRI are often subsequently performed for further characterization, assessment of precise extent, and detection of associated metastatic disease in cases of malignant hepatic neoplasm. Serological markers (such as alpha fetoprotein) can be useful in narrowing the differential diagnosis when they are markedly elevated but a substantial number of patients unfortunately do not have high levels of these markers at the time of presentation or cautious interpretation is warranted as AFP level is frequently elevated in infants up to 6 mo of age and may be slightly elevated with benign tumors and with hepatic insult or regeneration. Therefore, a tissue diagnosis is often required to guide subsequent management. The histology and anatomy of a pediatric liver tumor guides the treatment and prognosis.

Differential diagnosis and management of liver tumors in infants

During the first year of life, most of the liver neoplasms are benign in origin, but some of these histologically benign lesions may be challenging in their management. Although most hepatic hemangiomas can be safely observed until involution is documented, some patients will need treatment due to progressive hepatomegaly, hypothyroidism and/or cardiac failure. Large mesenchymal hamartomas may require extensive hepatic resection and an appropriate surgical plan is critical to obtain good results. For malignant neoplasms such as hepatoblastoma, complete surgical resection is the mainstay of curative therapy. The decision about whether to perform an upfront or delayed resection of a primary liver malignant tumor is based on many considerations, including the ease of resection, surgical expertise, tumor histology and stage, and the likely chemosensitivity of the tumor. This article reviews the initial management of the more common hepatic tumors of infancy, focusing on the differential diagnosis and treatment options.

Hepatic hemangioendothelioma in an infant with severe congenital neutropenia

Severe congenital neutropenia (SCN) is a rare disorder caused by heterogeneous genetic mutations. We describe here a rare association of SCN caused by a novel ELANE mutation and infantile hepatic hemangioendothelioma. In a 2-month-old infant, an abdominal ultrasound performed for omphalitis revealed a hepatic tumor, which was resected. Histopathology confirmed the diagnosis of hemangioendothelioma. Postoperatively, severe neutropenia was noted. Bone marrow examination showed myeloid maturation arrest, diagnostic of SCN. Mutation analysis for the neutrophil elastase gene identified a novel heterozygous de novo ELANE missense mutation in exon 2 (c.215T>A, p.Val72Glu). He was managed successfully with broad-spectrum antibiotics and high-dose granulocyte colony-stimulating factor.

Abdominal undifferentiated small round cell tumor with unique translocation (X;19)(q13;q13.3)

We describe a male with a large abdominal mass, most likely originating from the liver, with capsule rupture and tumor dissemination into the abdominal cavity. Adherence of the tumor to the diaphragm and lower right colon also were noted. A comprehensive evaluation of the mass revealed no tumor-defining histopathologic, immunocytochemical, ultrastructural, cytogenetic, or translocation features. The malignant tumor was found to have a novel translocation (X;19)(q13;13.3), which has not been reported in small round cell tumors of childhood or adults. The final diagnosis rendered was an undifferentiated small round cell tumor of uncertain cell of origin.

Stromal-predominant mesenchymal hamartoma of the liver with elevated serum alpha-fetoprotein level

Mesenchymal hamartoma of the liver (MHL) is an uncommon, benign, tumor-like lesion and is usually diagnosed in the first 2 years of life. Its pathogenesis remains unclear. Treatment of choice is radical excision. The authors report a case of solid stromal predominant MHL in a 12-month-old male infant who also had an elevated serum alpha-fetoprotein level. He also had hypospadias, which might represent a spectrum of developmental anomalies. It usually presents as an asymptomatic mass, however, as in the reported case, it may cause several complications due to the compression of surrounding structures. He was successfully treated with total excision of the pedunculated large tumor without any complication.

Tumors of the liver in children

In this review we examine the diagnosis and treatment of pediatric liver tumors- both malignant and benign. The two most common malignant tumors are hepatoblastoma and hepatocellular carcinoma. Hepatoblastoma is seen in younger children, hepatocellular carcinoma in older children. Other malignant liver tumors are quite rare and include biliary rhabdomyosarcoma, angiosarcoma, rhabdoid tumor, and undifferentiated sarcoma. The commonly seen benign liver tumors in children are infantile hemangioma, mesenchymal hamartoma, and focal nodular hyperplasia. Rare benign tumors are hepatic adenoma, which is occasionally seen in teenage girls, and teratoma which is a very rare liver tumor in infants.

Management of liver tumors in childhood

Primary neoplasms of the liver occur rarely during childhood and constitute only 0.3-2% of all pediatric tumors. However, they comprise a variety of entities including benign and malignant epithelial, as well as mesenchymal tumors, the most common of these being hepatoblastoma and hepatocellular carcinoma. Clinical presentation, especially in young children is relatively uniform with abdominal enlargement and a painless tumor, and often specific symptoms develop late. Prerequisites for clinical diagnosis are a comprehensive laboratory workup and good quality imaging mainly with ultrasound, as well as CT and/or MRI scans. Histological diagnosis is essential for differential diagnosis and may only be omitted in some hepatoblastoma patients of the typical age (6 months to 3 years) with an excessively elevated serum-alpha-fetoprotein. Surgery is the mainstay of treatment for all benign and malignant liver tumors. Hepatoblastomas mostly respond well to chemotherapy. Therefore, this modality should always be combined with surgical resection in these patients and in many cases can reduce the size of a large tumor to resectability. Prognosis nowadays usually is good in all benign tumors and hepatoblastoma, as well as in some other rare malignancies, but dismal in hepatocellular carcinoma and other chemotherapy non-sensitive malignant tumors.

Laparoscopy in the management of antenatally detected liver masses

Antenatally detected liver masses that are not clearly benign on postnatal investigation pose a management dilemma. Unless the diagnosis is clear, observation alone is risky. Improvements in radiological diagnosis permit confirmation of the benign nature of these masses in some instances, but it is usually difficult to distinguish them from malignant lesions. Since recent advances in ultrasound facilitate identification of liver masses during prenatal life, differential diagnosis of these masses has become a recurring issue in recent years. Laparoscopy may play a major role in the surgical management of right upper quadrant masses detected antenatally. We describe its use in a patient with an antenatally detected liver mass. No clear diagnosis could be made with radiologic investigation in the neonatal period. Definitive diagnosis was made laparoscopically: focal nodular hyperplasia was confirmed with laparoscopy and biopsy. In cases where the etiology of a liver mass remains unclear after radiologic investigation, laparoscopic intervention may prove beneficial in neonates and infants. We present an algorithm for the management of similar antenatally detected right upper quadrant lesions.

The neonate with an abdominal mass

Abdominal masses in neonates reflect a wide spectrum of diseases,from lesions that can cause significant morbidity and mortality,to conditions readily corrected surgically, to entities which maybe safely observed. It is incumbent upon the infant's physician to determine the nature of the mass in a timely, safe, and cost-effective manner.

Neonatal liver tumours

Primary liver tumours are very rare during the neonatal period, but increasing numbers of them are now diagnosed prenatally by routine ultrasound scan. A precise diagnosis is sometimes problematic because of non-specific clinical symptoms, misleading imaging and difficulties with histological interpretation. Benign infantile haemangioendothelioma usually undergoes spontaneous regression, but may be life-threatening due to congestive heart failure and/or consumptive coagulopathy when treatment with resection, embolization or arterial ligation is necessary. Malignant hepatoblastoma may occur in the newborn, and often has to be treated with chemotherapy to achieve resectability. Symptoms are less specific and the prognosis is worse than in older children. Mesenchymal hamartoma is a benign cystic lesion that should be resected whenever possible. Rarely, germ cell tumours occur in the neonatal liver. Benign teratomas have to be resected, while malignant choriocarcinomas may respond to chemotherapy and can be cured in some cases.

Hepatobiliary infections

The major hepatobiliary infections (excluding the viral hepatitides) include amebic and pyogenic liver abscess and cholangitis. Little new information has been published in the area of cholangitis during the last several years. In contrast, the clinical presentation and management of liver abscess have evolved considerably, not only in the last several years but also during a more extended period spanning the last two decades. In the United States, amebic liver abscess occurs largely in individuals from endemic areas or in those traveling to endemic areas. Recent data suggest that patients with human immunodeficiency virus (HIV) infection are at an increased incidence of amebic liver abscess. New serologic tests and molecular techniques are being added to the diagnostic armamentarium for amebic liver abscess. In most cases, amebic liver abscess is associated with an excellent prognosis (up to 100% survival) if properly managed. Pyogenic liver abscess, although commonly occurring in patients with known biliary tract disease, is often cryptogenic in origin (ie, no clear causal factor can be identified) or often is caused by underlying medical disorders. An emerging population of patients with pyogenic liver abscess includes those with complications of aggressive interventions (hepatic chemoembolization, cryoablation, liver transplantation). Pyogenic liver abscess was predominantly managed by surgical methods up until the early 1980s, but almost entirely has changed to being managed by interventional techniques; in 2000, this trend has continued. In contrast to amebic liver abscess, pyogenic liver abscess is associated with greater morbidity and mortality, ostensibly caused by the severity of the underlying disease in many patients. However, it should be emphasized that the prognosis of patients with pyogenic liver abscess, who do not have underlying comorbid conditions, is excellent.