TY - JOUR AR - ACO-2019-4-101 TI - Tics and Tumors, A Case Report of Babesiosis and IgG4 Retroperitoneal Fibrosis AU - Heather, Mannuel AU - Michael, Adashek AU - Nicholas, Burley JO - Annals of Clinical Oncology PY - 2019 DA - Wed 27, Nov 2019 SN - 2674-3248 DO - http://dx.doi.org/10.31487/j.ACO.2019.04.01 UR - https://www.sciencerepository.org/tics-and-tumors-a-case-report-of-babesiosis-and-igg4-retroperitoneal-fibrosis_ACO-2019-4-101 KW - Babesiosis, retroperitoneal fibrosis, tamoxifen, rituximab, IgG-4, ureteral compression AB - Retroperitoneal fibrosis (RPF) is a rare fibroinflammatory tumor of the retroperitoneum thought to be due to either idiopathic disease or related to underlying malignancy. Recently idiopathic RPF has been reclassified as an immune mediated IgG-4 related disease. When left unchecked, RPF often progresses, leading to compression of retroperitoneal structures and complete ureteral obstruction. Babesiosis is an intraerythrocytic parasitic disease that has demonstrated an in vitro association with increased IgG-4 levels. Both diseases are insidious, presenting with symptoms commonly identified as a viral prodrome, including malaise and fatigue. Within we present a case of a 68-year-old African American farmer with recent tick exposure who presented with symptoms of malaise, weight loss, elevated creatinine and new retroperitoneal mass. Serum testing revealed recent Babesiosis exposure, and biopsy revealed new onset retroperitoneal fibrosis. Once treated for babesiosis, the patient’s disease ceased its progression, and he remains on treatment with tamoxifen and stable disease. Further research of the in vivo association of babesiosis and IgG-4 related disease is needed.