A Case of Vanishing Metastatic Mass: Right Atrial Mass in the Setting of Primary Epithelioid Hemangioendothelioma of the Spine.

Epithelioid hemangioendothelioma (EHE) is a rare low-grade vascular neoplasm that is characterized as intermediate between benign hemangioma and high-grade angiosarcoma affecting 1 in 1,000,000 people worldwide. It has been described throughout the body with lung, liver, skin, and bone being the most frequent sites. Primary EHE of the spine has been reported in 56 cases so far with no correlation of age and sex. Our case highlights a rare clinical presentation, etiopathogenesis, diagnosis, and treatment of EHE of the spine with metastasis to the right atrium. This is the first documented case of EHE of the spine with metastatic spread to the heart treated with bevacizumab leading to resolution of the heart metastatic mass. Further studies are warranted to develop a treatment formula for this rare tumor, to consider combination chemotherapy and new adjuvant targeted immunotherapies to prevent progression of disease.

Paraneoplastic Seronegative Pauci-Immune Glomerulonephritis Associated with Lung Adenocarcinoma Responds to Rituximab: A Case Report.

Anti-neutrophil cytoplasmic antibodies (ANCA) play an important role in the pathogenesis of pauci-immune renal vasculitis. However, in 10% of the cases, ANCA are absent. We present a case of a 64-year-old man with a chronic untreated hepatitis C virus infection and Middle Eastern thalassemia who was ANCA-negative when he was hospitalized due to acute kidney injury and accounts for an uncommon presentation of renal vasculitis. The patient had earlier reported to have undergone local lobectomy and adjuvant chemotherapy (carboplatin/pemetrexed) for lung adenocarcinoma a month prior. IL-6 has been reported to be involved in the pathophysiological cascade causing pauci-immune glomerulonephritis amongst non-small cell lung cancer patients. Previous studies with subgroup analysis have demonstrated that ANCA negativity has been associated with more chronic glomerular lesions and less crescent formation, which tends to have a critical outcome in the renal system. However, our patient underwent kidney biopsy exhibiting active crescentic glomerulonephritis, pauci-immune type with 5 cellular crescents amongst 15 glomeruli. To our knowledge, this is the third reported case of ANCA-negative vasculitis with typical presentation on biopsy in non-small cell lung cancer patients.