P3C333: De-liver-ing a Diagnosis for Abdominal Pain

Introduction: Abdominal pain is a common presenting complaint in the pediatric population and can be diagnostically difficult due to the variety of underlying causes. Here we present an unusual cause of abdominal pain in a teenage patient.

Case Description: A 17 year old previously healthy male presented to the emergency department with one day of sharp, intermittent right upper quadrant pain and fever. He had no weight loss, nausea, vomiting, changes in appetite, jaundice, or other symptoms. There was no history of recent travel, animal exposures, or known sick contacts. He was up to date on immunizations. He had never had similar pain previously. The patient started taking isotretinoin for acne in the last week but otherwise took no medications. He did not report any alcohol, tobacco, or other drug use. Family history was unremarkable. The patient was afebrile with normal vital signs. His exam was notable for hepatomegaly with the liver being palpable 6 cm below the right costal margin and splenomegaly. There was tenderness to palpation in right upper quadrant and epigastric area but no rebound or guarding. Initial workup was notable for an elevated CRP of 4.1 mg/dL and LDH of 498 U/L. CBC, CMP, lipase, amylase, uric acid, urinalysis, urine drug screen, and viral PCR testing were all normal. Ultrasound of the appendix was normal. US of the gallbladder revealed an enlarged liver with multiple hypoechoic lesions (see figure 1). A CT scan of the abdomen (see figure 2) showed multiple masses in an enlarged liver and spleen. The Infectious Disease team recommended further workup with Echinococcus granulosus, Entamoeba histolytica, and Bartonella henselae testing which returned negative. The Oncology team recommended obtaining flow cytometry which was also negative. The patient eventually went for an IR guided biopsy of his liver lesions. The biopsy results were consistent with a malignant vascular neoplasm known as Epithelioid Hemangioendothelioma (EHE). Molecular testing of markers determined the presence of WWTR1-CAMTA1 fusion product seen in EHE and not in other malignant vascular tumors such as angiosarcomas.

Discussion: EHE is an ultra-rare cancer that arises from the endothelial cells lining the vasculature and can occur anywhere in the body. EHE has an incidence of 1/1,000,000 and is more commonly found in elderly patients. Very few cases have been reported in pediatrics. There are no standardized treatments but small studies that have shown disease stabilization with mTOR inhibitors. In some cases, the tumor has regressed without any treatment.

Conclusion: Although EHE and other vascular neoplasms are an unlikely cause of abdominal pain, they can arise anywhere and should be considered when a patient presents with unifocal or multifocal lesions. Given the variability in presentation and symptoms for EHE patients, biopsy is ultimately necessary in order to deliver the diagnosis.