Abstract: SA-PO0760
Anterior Mediastinal Hematoma Mimicking a Mass in ESRD: A Rare Presentation of Hydralazine-Induced Lupus (HIL)
Session Information
- Glomerular Diseases: Lupus Nephritis, Monoclonal Gammopathy-Related Disease, and Transplantation
October 24, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Yousaf, Uzma, Loyola University Chicago, Chicago, Illinois, United States
- Joseph, Thomas, Loyola University Chicago, Chicago, Illinois, United States
- Ling, Benjamin, Loyola University Chicago, Chicago, Illinois, United States
Introduction
Hydralazine-induced lupus (HIL) is a rare cause of inflammatory serositis and can be particularly challenging to recognize in patients with end-stage renal disease (ESRD), where effusions could be attributed to uremia or volume overload. We present a case of a 44-year-old ESRD patient on peritoneal dialysis (PD) with an interesting combination of findings in the setting of increased hydralazine dosing, namely positive anti-histone serology, hemorrhagic serositis with cardiac tamponade, sanguinous pleural effusion, and an anterior mediastinal hematoma mimicking a mass.
Case Description
A 44-year-old Hispanic male with ESRD on PD had his hydralazine dose increased to 225 mg/day for uncontrolled hypertension by his primary care physician. Within a couple of months, he presented with progressive dyspnea, fatigue, and chest discomfort. Chest imaging revealed a large pericardial effusion, a 6.6 cm anterior mediastinal mass, and a left-sided pleural effusion. With no evidence of peritonitis and pleuroperitoneal leak, PD was continued. HIL was strongly suspected, given the features of diffuse inflammatory serositis in the context of recent hydralazine dose escalation. This was later confirmed serologically with findings of an elevated ANA titer of 1:1280 (homogenous), positive anti-histone antibodies, and negative dsDNA and ANCA. Further evaluation of the mediastinal mass favored hematoma rather than malignancy due to its heterogeneous density. Despite initial hemodynamic stability, he was readmitted within a couple of days with cardiac tamponade and required urgent pericardiocentesis, draining 200 ml of hemorrhagic fluid. Hydralazine remained discontinued, leading to clinical improvement with no recurrence of serositis or effusions to date.
Discussion
This case highlights the rare development of a mediastinal hematoma that mimics an anterior mediastinal mass, a previously undescribed manifestation of HIL. It further demonstrates the diagnostic challenge in PD patients, where autoimmune serositis is often masked by more common etiologies such as uremia, infection, malignancy, or pleuroperitoneal leak.