Giant Cavernous Hepatic Hemangioma Masking a Separate Pleural Empyema: A Diagnostic Pitfall and Anchoring Bias.

Giant cavernous hepatic hemangiomas may occasionally demonstrate atypical imaging characteristics that mimic malignant or infectious hepatic lesions, creating diagnostic uncertainty and increasing the risk of anchoring bias. We report the case of a 41-year-old male who presented with fever, pleuritic chest pain, leukocytosis, and a large right pleural effusion following CT-guided lung biopsy. Imaging revealed a large hepatic lesion with atypical radiographic features concerning for malignancy or disseminated infection, along with pulmonary inflammatory changes and empyema. Thoracentesis yielded pleural fluid concerning for empyema. Given the constellation of findings, the hepatic lesion initially dominated diagnostic reasoning and raised concern for a unifying metastatic or infectious process. However, liver biopsy ultimately confirmed cavernous hepatic hemangioma, while pulmonary biopsy demonstrated inflammatory changes without evidence of malignancy. Histopathologic evaluation established that the hepatic lesion was incidental and unrelated to the patient's acute illness, whereas the empyema was most likely secondary to the recent thoracic intervention. This case highlights the importance of avoiding anchoring bias and recognizing concurrent but unrelated disease processes when evaluating complex clinical presentations.