Background: Carcinoembryonic antigen (CEA) is a polysaccharide complex present in the human respiratory system, which can reflect the presence of tumors in the human body and has important value in the monitoring of lung cancer , but sometimes serum CEA provides limited help. We reported a case of multiple consolidation of the lungs with elevated serum CEA, initially misdiagnosed as lung cancer and eventually confirmed by bronchoscopic lung biopsy as pulmonary cryptococcosis (PC).
Methods: Appropriate laboratory examination, chest computed tomography (CT) scan, and bronchoscopy lung biopsy were used to explore the latent etiology.
Results: CEA level was elevated, chest CT scan showed multiple consolidation of the lungs, serum cryptococcal antigen was positive, and pathological findings on bronchoscopic lung biopsy confirmed pulmonary cryptococcosis.
Conclusions: Elevated CEA is not typical of lung cancer. We should also consider the possibility of specific pathogenic infection. Bronchoscopic lung biopsy is the gold standard should be performed as soon as possible to identify the lesion.