CHEST Guidelines-Giant-Intrathoracic-Mass-in-a-Young-Woman-With-Acu

Giant-Intrathoracic-Mass-in-a-Young-Woman-With-Acu

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A 35-year-old woman with a three-week history of fatigue and dry cough was diagnosed with a benign thymic tumor called lipofibroadenoma, accompanied by renal-limited ANCA-associated vasculitis (AAV). Initial symptoms included severe anemia and acute kidney injury, with lab tests showing elevated creatinine and proteinuria. A chest radiograph revealed a giant mediastinal mass, later identified via CT as a fatty tumor occupying a large portion of the thoracic cavity.<br /><br />A renal biopsy confirmed pauci-immune glomerulonephritis linked to high anti-myeloperoxidase (ANCA) levels, indicative of AAV. No vasculitis involvement was found in other organs. A biopsy initially suggested a well-differentiated liposarcoma; however, gene testing ruled out this malignancy, leaving the tumor's complete nature undefinable without resection.<br /><br />The patient underwent therapeutic plasma exchange and glucocorticoids for AAV remission, switching to cyclophosphamide when malignancy was ruled out. Surgical intervention was necessary due to the tumor's life-threatening size. The first surgery removed 8 kg from the left hemithorax, with the remaining 5 kg excised six months later from the right side. <br /><br />Histological examination post-resection confirmed the tumor closely resembled a fibroadenoma, not a malignancy, and likely originated from the thymus. There was no evidence of malignant thymoma. The patient responded well to treatment, showing resolution in anemia and improvement in renal function without AAV flares. Despite successful procedures, her kidney function continued to decline, requiring ongoing dialysis while awaiting transplantation.<br /><br />The case underscores the importance of considering autoimmune diseases with thymic tumors, as these can manifest concurrently. This report is notably the first of lipofibroadenoma with associated AAV, suggesting a possible, though unconfirmed, linkage between these rare conditions.

Keywords

lipofibroadenoma

ANCA-associated vasculitis

thymic tumor

pauci-immune glomerulonephritis

anti-myeloperoxidase

plasma exchange

glucocorticoids

cyclophosphamide

renal biopsy

mediastinal mass