A 9-month-old boy has been referred to you for the evaluation of an enlarged abdomen. Imaging studies show a large liver mass (PRETEXT III). Alfa-fetoprotein is 98 ng/mL, and a CT scan of the lungs show bilateral lung metastases. A needle biopsy is performed, and you are planning to review the specimen with the pathologist. Which of the following diagnoses are you suspecting?
Correct Answer: D
Rationale: The correct answer is D: Small cell undifferentiated hepatoblastoma. In this case, the key features to consider are the patient's age (9 months old), large liver mass with lung metastases, and elevated alpha-fetoprotein level. Small cell undifferentiated hepatoblastoma is commonly seen in infants, presents as a large liver mass, and frequently metastasizes to the lungs. The alpha-fetoprotein level in this case is also elevated, which is typical for hepatoblastoma. Pure fetal histology hepatoblastoma (A) is less common in older infants, and the presence of lung metastases is not typical. Embryonal sarcoma (B) typically presents as a solitary mass without metastases. Fibrolamellar hepatocellular carcinoma (C) is rare in infants and does not typically present with elevated alpha-fetoprotein levels. Thus, based on the clinical presentation and imaging findings, small cell undifferentiated hepatob