False-negative PET scan with bronchioloalveolar carcinoma: an important diagnostic caveat

Positron emission tomography (PET) is becoming widely accepted as a powerful diagnostic tool for the diagnosis of lung cancer, but it has very poor sensitivity for the detection of bronchioloalveolar carcinoma (BAC) and adenocarcinoma with BAC pattern, the less common form of pulmonary neoplasia. We present a case of a patient with a negative PET scan who might have been followed by observation but was found to have bronchioloalveolar carcinoma at thoracotomy. PET has a reported sensitivity of over 98% in most series but misses almost two-thirds of BAC lesions, which might delay invasive testing and early diagnosis of this potentially lethal cancer. Although this diagnostic limitation has been well reported in the radiology literature, the high reported sensitivity and sensitivity can give clinicians a false sense of security with negative PET scans of lung nodules. The usual risk factors for bronchogenic carcinoma are less reliable for these subtypes of non-small-cell lung cancer; thus, clinicians need to have a high index of suspicion for BAC and exercise caution when making decisions on the basis of PET.