Metastatic Pulmonary Epithelioid Hemangioendothelioma: A Case Report

Abstract

Introduction: Pulmonary Epithelioid hemangioendothelioma (EHE) is a rare vascular tumor;with approximately 248 cases of reported in the literature, making diagnosis and management challenging. Case: A 57-year-old female with past history of hypertension, hyperthyroidism and scoliosis was admitted with worsening chronic right flank pain. Initial lab workup was unremarkable. revealed COVID-19 PCR test was negative. CT chest revealed bilateral pleural effusions and CT abdomen showed 2.8 x2.0cm vague hypo-attenuating lesion in the right hepatic lobe. A repeat CT scan following thoracentesis demonstrated multiple bilateral pulmonary nodules, with the largest located in the right lower lobe (RLL) measuring 2.1cm (Image). Flowcytometry on bronchoalveolar lavage fluid was significant for a CD4/CD8 ratio of 5;however, the transbronchial biopsy was unremarkable. Differential diagnosis included sarcoidosis and hence patient was discharged on prednisone with Bactrim prophylaxis. She underwent VATS lung biopsy. RLL and pleural biopsies revealed EHE. Following the prednisone taper, patient was placed on pazopanib 800mg. The dose of medication subsequently reduced to 300-600mg due to adverse events. Repeat CT scans at 3 months demonstrated minimal change in size of the nodules. Patient continues to be followed on regular basis with a stable clinical status. Discussion: EHE is a low-intermediate grade malignancy which affects mostly liver, lungs and bones;although it can be found in any bodily tissue. Up to 50- 76% of patients are asymptomatic at diagnosis, with the most common symptomatic being local pain. Radiologically, Pulmonary EHE consists of bilateral perivascular nodularity. Our case describes the clinical course of a rare and poorly understood disease. Clinicians must be aware of the characteristics of unusual diseases and pursue robust diagnostic approach. In our case, biopsy led to the definitive diagnosis of EHE. Because of its rarity, there is no standard therapy for metastatic disease. Pazopanib has demonstrated prolonged long-term disease control in observational studies. Some other reports have shown response to cytotoxic chemotherapy such as doxorubicin-containing regimens, however, long-term survival is compromised. Lenalidomide, sorafenib and sunitinib have also been used, but the experience is limited. Our patient is currently on her 4th month of treatment with pazopanib, with 3-month follow-up showing no progression of disease. (Figure Presented).