Primary splenic epithelioid hemangioendothelioma with diffuse metastases revealed by FDG PET/CT imaging A case report

Rationale: Epithelioid hemangioendothelioma (EHE) is a rare low-to-intermediate grade malignant vascular neoplasm. We report a primary splenic EHE with diffused metastasis who underwent F-18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT). Our case emphasizes that EHE should be considered a differential diagnose of F-18-FDG-avid splenic malignancies. Patient concerns: A 39-year-old man presented with abdominal distension and chest distress for 20 days and lumbago for 2 days. Transthoracic echocardiography suggested a large amount of pericardial effusion. Contrast-enhanced CT imaging showed splenomegaly with multiple low-density nodules with ring enhancement. A large irregular mass was also found in the right superior mediastinum with heterogeneous density and enhancement. F-18-FDG PET/CT imaging revealed splenomegaly, filled with intense hypermetabolic nodules and masses. And multiple regions of increased F-18-FDG uptake were observed in the mediastinum, left pleura, and bones. Diagnosis: EHE of the spleen. Interventions: Half a month after the diagnosis was confirmed, the patient then underwent chemotherapy, Docetaxel combined with carboplatin, and Endu were administrated every 3 weeks. Outcomes: During the 6-month follow-up period, the patient has finished 4 cycles of chemotherapy combined with 2 months of targeted drug. Efficacy assessment is partial remission through CT imaging, and clinical symptoms of patient improved significantly. Lessons: Primary splenic EHE is extremely rare, especially with diffuse systemic metastasis. Our report suggested that EHE should be considered a differential diagnosis of F-18-FDG-avid splenic malignancies. Furthermore, F-18-FDG PET/CT plays critical role in staging and accessing disease extent of EHE.