A high riding superior pericardial recess, a benign anatomical variant, can closely mimic pathologic mediastinal masses or lymphadenopathy on cross-sectional imaging.
Case Report (n=1)
A high riding superior pericardial recess is a benign anatomical variant that can mimic a mediastinal mass, and comprehensive multimodal imaging is crucial to prevent unnecessary invasive diagnostic procedures.
Abstract Introduction Mediastinal masses encompass broad differentials of reactive, inflammatory, infectious or neoplastic etiology. In the background of extra thoracic malignancy, it raises a high suspicion for primary cancer or metastatic lymphadenopathy. However, a benign anatomical variant can mimic these findings and lead to unnecessary diagnostic procedures and patient anxiety. Recognizing mimickers becomes crucial in avoiding misdiagnosis and overtreatment. Case A 50-year-old woman with no significant past medical history presented with a two-day history of headache, associated with cough, orthopnea and lower extremity edema. Vital signs were significant for elevated blood pressure at 199/107 mm Hg. Laboratory findings noted a markedly elevated B-type natriuretic peptide (19,000 pg/mL), increased serum creatinine (1.4 mg/dL from baseline 0.7 mg/dL) and proteinuria. Chest X-ray revealed pulmonary vascular congestion. Autoimmune serologies were positive for antinuclear antibody (titer 1:2560), ribonucleoprotein antibody, and RNA polymerase III antibody. Renal biopsy confirmed scleroderma renal crisis. She was treated for hypertensive emergency secondary to scleroderma renal crisis. Further evaluation for elevated total protein revealed monoclonal gammopathy on electrophoresis and 30% plasma cells on bone marrow biopsy, consistent with smoldering multiple myeloma. A chest computed tomography scan incidentally identified a 4 × 3 cm lobular right paratracheal mass. Tissue biopsy was requested to exclude plasmacytoma. Bronchoscopy with endobronchial ultrasound revealed a large hypoechoic paratracheal lesion. Biopsy was aborted due to its cystic appearance and risk of airway flooding. Subsequent magnetic resonance imaging was obtained for tissue characterization which delineated the mass as a thin walled, fluid filled structure communicating with the superior aortic recess, consistent with a high riding superior pericardial recess which is a benign anatomical variant. She was discharged with plans for outpatient multidisciplinary follow up, including pulmonary evaluation for interstitial lung disease surveillance. Discussion High riding pericardial recess is a benign anatomical variant which can closely mimic pathologic masses or lymphadenopathy on cross sectional imaging. Key is identification of probable communication with the superior aortic recess associated with fluid attenuation. Knowledge of anatomy, comprehensive multimodal imaging review, and multidisciplinary discussion are key to prevent unnecessary investigation of mediastinal abnormalities. This abstract is funded by: None
Onkaramurthy et al. (Fri,) conducted a case report in High riding superior pericardial recess mimicking a mediastinal mass (n=1). A high riding superior pericardial recess, a benign anatomical variant, can closely mimic pathologic mediastinal masses or lymphadenopathy on cross-sectional imaging.