Malignant rhabdoid tumor of the liver: Findings at US, CT, and MRI, with histopathologic correlation

Review on Pediatric Malignant Focal Liver Lesions with Imaging Evaluation: Part II

Malignant focal liver lesions (FLLs) represent various kinds of epithelial and mesenchymal tumors. In pediatric patients, the understanding of pediatric liver diseases and associated imaging manifestations is essential for making accurate diagnosis and differential diagnosis. This paper will discuss the latest knowledge of the common pediatric malignant FLLs, including undifferentiated embryonal sarcoma, rhabdomyosarcoma, epithelioid hemangioendothelioma, angiosarcoma, and malignant rhabdoid tumor. Medical imaging features are not only helpful for clinical diagnosis, but can also be useful in the evaluation and follow-up of pre- and post-treatment. The future perspectives of contrast-enhanced ultrasound (CEUS) enhancement patterns of FLLs in pediatric patients are also mentioned.

Update on the Pathology of Pediatric Liver Tumors: A Pictorial Review

Liver tumors in children are uncommon and show remarkable morphologic heterogeneity. Pediatric tumors may arise from either the epithelial or mesenchymal component of the liver and rarely may also show both lines of differentiation. Both benign and malignant liver tumors have been reported in children. The most common pediatric liver tumors by age are benign hepatic infantile hemangiomas in neonates and infants, malignant hepatoblastoma in infants and toddlers, and malignant hepatocellular carcinoma in teenagers. Here, we provide an up-to-date review of pediatric liver tumors. We discuss the clinical presentation, imaging findings, pathology, and relevant molecular features that can help in the correct identification of these tumors, which is important in managing these children.

Primary Malignant Rhabdoid Tumor of the Liver in a 5-Month-Old Female Who Presented with Abdominal Distension

BACKGROUND Malignant rhabdoid tumors are rare and aggressive pediatric tumors that usually arise in the kidney and have a characteristic appearance on histology. Extrarenal malignant rhabdoid tumors originating in the liver are extremely rare. This report is of a 5-month-old girl who presented with a rapidly enlarging abdominal mass due to a malignant rhabdoid tumor of the liver. CASE REPORT A 5-month-old female patient with no known medical history had been experiencing increasing abdomen distention and less overall activity for 1 month, according to her parents. Abdominal ultrasonography was used for diagnostic purposes, and the results showed the presence of a mass with a solid and cystic appearance in the upper left quadrant of the abdomen. The patient was transferred to a tertiary care hospital for further investigations. The laboratory test results indicated a hemoglobin level of 8.2 g/dL, and the liver function tests were within the reference range. However, the serum tumor marker alpha-fetoprotein level was 1310 ng/mL, while the b-human chorionic gonadotropin was within range. Computed tomography detected a nonspecific heterogeneous mass of the liver. Histopathology revealed discohesive cells with rich eosinophilic cytoplasm, eccentric nuclei, and large central nucleoli (rhabdoid appearance). Immunohistochemistry showed negative integrase interactor 1 protein expression. The diagnosis was a primary malignant rhabdoid tumor located in the liver. CONCLUSIONS This report shows the importance of combined diagnostic imaging and histopathology analysis to confirm the diagnosis of rare pediatric tumors, including malignant rhabdoid tumor, to ensure early diagnosis and appropriate treatment.

Primary extrarenal rhabdoid tumour of the liver: a case report and literature review

Background

Extrarenal rhabdoid tumours (ERT) are highly aggressive tumours that are poorly responsive to standard cytotoxic chemotherapy and are associated with a grim prognosis. Primary ERT of the liver are most commonly observed in early childhood and exceptionally rare later in life.

Case presentation

We report the case of a 16-year-old male patient, presenting with flu-like symptoms after his second COVIDvaccination. During the work-up, a large solid liver lesion was incidentally discovered upon abdominal ultrasound examination. Pathological examination rendered the diagnosis of primary ERT of the liver, characterized by the loss of expression of INI-1 protein, encoded by the SMARCB1 gene. We summarized and discuss the existing literature by reviewing 53 pediatric and 6 adult cases, including the histological features treatment and outcomes of primary hepatic ERT.

Conclusion

Primary ERT of the liver are usually not associated with specific signs or symptoms, making the diagnosis very challenging. As ERT are associated with a high metastatic rate, delayed diagnoses lead to increased mortality, as complete resection is not possible in advanced-stage cases. Therefore, early diagnoses, enabling complete resection of the tumour are crucial to improve patient outcomes. Of interest, primary ERT of the liver, is associated with biallelic loss of the SMARCB1 (SWI/ SNF Related, Matrix Associated, Actin Dependent Regulator Of Chromatin, Subfamily B, Member 1) gene, a potential target for cancer therapeutics. This is, to our knowledge, the first case of a hepatic rhabdoid tumour treated with liver transplantation.

Malignant rhabdoid tumour of liver: Conundrum on ascitic fluid

Ascitic fluid analysis is an important tool for diagnosis and staging. Cytological analysis is routinely done as a part of workup for ascites. This is challenging in paediatric malignancies where multiple differentials need to be considered at times with limited cellularity. We present a case of malignant rhabdoid tumour of liver in a young child presenting with abdominal lump and ascites. The diagnosis was offered on ascitic fluid cytology based on cytomorphology, supporting immunohistochemistry and later confirmed on biopsy. This report briefly discusses its differentials and approach to diagnosis.

Cytologic features of malignant rhabdoid tumor of the liver: A case report and literature review

As one of the SMARCB1-deficient tumors, malignant rhabdoid tumor (MRT) of the liver is a rare and aggressive malignancy, typically in young children below the age of 3 years. The diagnosis of MRT of the liver is challenging both clinically and pathologically due to the rarity of the tumor and misdiagnosing it as a hepatoblastoma is not uncommon. Although MRT of the liver and hepatoblastoma share some similar clinical and morphological features, their prognosis and the clinical management are significantly different. Therefore, an accurate diagnosis of MRT or hepatoblastoma is critical for patient care. Here we report a case of an 8-month-old female with MRT of the liver diagnosed by fine needle aspiration and core biopsy. The cytologic and histological features, the results of immunohistochemical studies, and clinical follow-up information are presented. Recent literature regarding the diagnosis and treatment of this tumor were reviewed.

Pediatric Primary Hepatic Tumors: Diagnostic Considerations

The liver is the third most common site of abdominal tumors in children. This review article aims to summarize current evidence surrounding identification and diagnosis of primary hepatic tumors in the pediatric population based upon clinical presentation, epidemiology, and risk factors as well as classical imaging, histopathological, and molecular diagnostic findings. Readers will be able to recognize the features and distinguish between benign and malignant hepatic tumors within different age groups.

Pediatric Liver Tumors

Although liver tumors are rare in the pediatric population, they are common in the setting of children with specific risk factors requiring increased awareness and, in some instances, screening. The evaluation of a liver mass in children is largely driven by the age at diagnosis, the presence of any medical comorbidities, and initial testing with alpha fetoprotein and imaging. Specific guidelines for the management of different tumors have been implemented in recent years such that a multidisciplinary approach is ideal and care should be provided by centers with experience in their management.