C40-18 The Tumor That Wasn’t: An Atypical Presentation of Sarcoidosis

Abstract Introduction Sarcoidosis, a systemic granulomatous disease, can affect any organ, but most often involves the lungs (∼95%) and lymph nodes with a bimodal age of presentation (20-30 and 50-60 years). Although typically presenting with bilateral, symmetric hilar lymphadenopathy, its clinical course and radiological presentation can be highly variable. We present a case of a well-controlled HIV patient with an aggressive, large right paratracheal mass mimicking malignancy, highlighting an atypical presentation of sarcoidosis. Case Presentation A 79-year-old female with chronic obstructive pulmonary disease, well-controlled HIV (CD4 count 897 cells/mm³), and a history of disseminated Mycobacterium avium complex infection presented with worsening dyspnea, low-grade fevers, and night sweats for 2 months. Computed tomography angiography of the chest showed a large 4.3 cm x 3.7 cm right paratracheal mass, with significant compression on the trachea and right mainstem bronchus, and mediastinal lymphadenopathy with a necrotic lymph node in the aortopulmonary window. A PET (positron emission tomography) scan showed intense fluorodeoxyglucose uptake. Due to suspicion of malignancy, endobronchial ultrasound-guided transbronchial needle aspiration was performed on the paratracheal mass, and a separate biopsy was taken of the endotracheal mass. Pathology on both biopsies revealed noncaseating granulomatous inflammation without any evidence of malignancy. Acid-fast bacilli and fungal cultures on these biopsies were negative. The Angiotensin-Converting Enzyme (ACE) level was at the upper limit of normal range (51 U/L). As the paratracheal mass caused respiratory distress due to significant tracheal compression, the patient underwent rigid bronchoscopy with debulking of the mass, which provided marked symptomatic improvement. A repeat biopsy confirmed non-caseating granulomatous inflammation. Prednisone treatment for suspected sarcoidosis led to clinical and radiographic improvement after opportunistic infections were ruled out. Discussion This case highlights sarcoidosis as a “great imitator” of aggressive malignancy, presenting atypically as a paratracheal mass. Sarcoidosis usually presents with mild peribronchovascular thickening and hilar adenopathy. The aggressive radiologic features and high metabolic activity on PET imaging mandated a thorough evaluation. Malignancy was excluded based on the absence of cellular atypia and negative immunohistochemical staining. Infectious causes, including tuberculosis, non-tubercular mycobacteria, and fungal infections, were ruled out. The near-normal serum ACE level reflects the limited diagnostic utility of this biomarker in localized disease, emphasizing the need for histopathologic confirmation. For a conclusive diagnosis, demonstrating noncaseating granulomas in at least two noncontiguous biopsy sites is recommended. Finally, in cases of airway compression, prompt mechanical intervention through debulking in addition to corticosteroid therapy can provide rapid symptomatic relief. This abstract is funded by: None