Abstract Tumor lysis syndrome (TLS) typically follows cytotoxic therapy for hematologic malignancies. Spontaneous TLS (sTLS) at presentation, especially with an acute respiratory failure and undiagnosed thoracic malignancy, is uncommon and requires time-sensitive management. We report a case of sTLS that unmasked an aggressive lymphoproliferative disorder after multiple non-diagnostic bronchoscopic procedures, with the diagnosis ultimately confirmed by repeat pleural fluid cytology. Case of a middle-aged man presenting several weeks of weight loss, anorexia, and progressive dyspnea, rapidly deteriorating and developing an acute hypoxemic respiratory failure that required immediate endotracheal intubation and ICU admission upon arrival. Initial studies revealed sTLS with severe hyperuricemia (30 mg/dL), hyperkalemia (7.8 mmol/L), hypocalcemia (4.9 mg/dL), and metabolic acidosis (pH 7.18; HCO3− 13 mmol/L), accompanied by an anuric acute kidney injury (AKI). He received rasburicase, high-dose dexamethasone, meticulous electrolyte control, and intermittent hemodialysis, with serum urate declining to 3.6 mg/dL and partial clinical stabilization. Cross-sectional imaging demonstrated a ∼13-cm heterogeneous, partially necrotic right-lung mass with mediastinal lymphadenopathy, bilateral pleural effusions, and a small pericardial effusion. Initial diagnostic attempts were unrevealing; bronchial washings and two broncho-alveolar lavages (BALs) were negative for malignancy. Transbronchial fine-needle biopsies (FNAs) of the right mass and 11R node and a small forceps biopsy were non-diagnostic, only necrotic tissue obtained. Early left-sided pleural fluid cytology was reported as negative for malignancy with reactive mesothelial cells and supportive immunostains. A subsequent left pleural tap showed lymphocyte-predominant effusion and that warranted flow cytometry. Within 48 hours, right pleural fluid cytology returned positive for malignancy, demonstrating a lymphoproliferative disorder, and repeat bilateral pleural fluids confirmed malignant lymphomatous effusions. With the new cytology, hematology service initiated expedited immunophenotyping (flow cytometry) and viral testing to define subtype and begin definitive therapy. Spontaneous TLS can be the presenting syndrome of aggressive lymphoma, even before therapy. Abrupt hyperuricemia with phosphate elevation, hypocalcemia, and AKI meeting Cairo-Bishop laboratory and clinical criteria, should trigger treatment before tissue confirmation. When early endobronchial/transbronchial sampling is non-diagnostic in a necrotic, bulky thoracic mass, clinicians should biopsy smart; either target non-necrotic areas via EBUS/IR or shift to pleural fluid cytology/flow, which may yield faster, and safer diagnosis in unstable patients. Teams must balance diagnostic yield against renal risk and respiratory instability. In this patient, immediate rasburicase and dialysis stabilized multiorgan failure, and created a window for high-yield sampling that ultimately established a lymphoproliferative malignancy. This abstract is funded by: None
Raimundi et al. (Fri,) studied this question.