Complete metabolic response to therapy of hepatic epithelioid hemangioendothelioma evaluated with 18F-fluorodeoxyglucose positron emission tomography/contrast-enhanced computed tomography: A CARE case report.

Rationale: Hepatic epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor of endothelial origin with a highly variable clinical presentation and natural history. Given its vascular origin, new therapies with inhibitors of vascular endothelial growth factor (VEGF) have been introduced in the treatment of these patients and have shown promising results. Few reports have described the role of F-Fluorodeoxyglucose positron emission tomography/contrast-enhanced computed tomography (F-FDG PET/CT) in the evaluation of this tumor after treatment with anti-angiogenic agents. Our case reports how F-FDG PET-CT scan was critical in the assessment of this tumor after treatment with an anti-angiogenic agent, Pazopanib, demonstrating complete metabolic response.

Patient Concerns: A 30-year-old man with no previous significant medical history presented with pain in the right upper quadrant for over a year.

Diagnoses: Multiple hepatic masses were found on abdominal ultrasound. Liver biopsy confirmed the diagnosis of epithelioid hemangioendothelioma. F-FDG PET/CT was performed for staging. Multiple FDG-avid hepatic, splenic, and lymph nodes lesions were detected on F-FDG PET/CT. A subsequent spleen biopsy confirmed splenic involvement. Immunohistochemistry was positive for CD31, CD34, and ERG, supporting the diagnosis of epithelioid hemangioendothelioma.

Interventions: A 1-year cyclophosphamide treatment was provided followed by Pazopanib for 17 months.

Outcomes: Six years after the first F-FDG PET/CT, F-FDG PET/CT performed for restaging demonstrated complete metabolic response to therapy. Follow-up CT demonstrated no interval changes in size of some of the treated lesions.

Lesson: F-FDG PET/CT is useful for baseline assessment and posttreatment follow-up of this rare cancer.