Chest Film Clinic: What caused persistent cough and dyspnea in this patient?

The patient's past medical history and occupational exposures were unremarkable. Her travel history included a trip to Mexico 1 month before presentation. Her tuberculosis exposure was unknown. The patient reported a 20-pack-year history of cigarette smoking, but she quit smoking more than 20 years ago. On physical examination, she appeared to be well with no respiratory distress. She was afebrile, her blood pressure was 183/100 mm Hg, and her oxygen saturation was 97% on room air. Lungs were clear to auscultation, and breath sounds were equal bilaterally. Results of her cardiac examination were normal. There was no supraclavicular or cervical lymphadenopathy. Extremities showed no cyanosis or clubbing. On presentation, laboratory test results, including white blood cell count, were all within normal limits. Posteroanterior (PA) and lateral chest radiographs were obtained. The PA radiograph is shown below (Figure 1).Making the diagnosis The PA chest radiograph demonstrated consolidation in the right upper lobe, with bulging of the adjacent fissure. Cardiac and mediastinal contours were normal, with no lymphadenopathy. The patient was treated with antibiotics for a presumptive diagnosis of community-acquired pneumonia. On her follow-up visit, she reported mild improvement of her symptoms, but a chest radiograph did not show any improvement. A CT scan of the chest obtained after intravenous administration of contrast material demonstrated consolidation in the right upper lobe (Figure 2). A CT angiogram sign was present. This sign, which refers to the presence of enhancing vessels simulating an angiogram in an area of low-attenuation consolidation, was originally described in association with bronchoalveolar cell carcinoma.1 In this setting, the high-attenuation, enhancing pulmonary vessels contrast with the low attenuation of mucinous tumor in the lung parenchyma. There was no evidence of obstructing endobronchial lesions or significant mediastinal lymphadenopathy. The patient subsequently underwent fiberoptic bronchoscopy with bronchoalveolar lavage (BAL), which demonstrated no evidence of infection or malignancy. Because of the chronicity of the right upper lobe consolidation, the absence of response to antibiotics, and the presence of a CT angiogram sign, bronchoalveolar carcinoma was the leading diagnosis. A whole-body positron emission tomography (PET) scan was obtained for further characterization of the lesion and for evaluation of distant spread of disease. On PET imaging, low-level fluorodeoxyglucose (FDG) activity was seen in the periphery of the lesion, with no significant uptake elsewhere in the body. The negative findings on the PET scan suggested that there was no active infection, which would typically avidly accumulate FDG. Although a definitive diagnosis had not yet been made, the low-level activity on PET correlated with the presumptive diagnosis of bronchoalveolar carcinoma, given that this non-small-cell lung cancer often demonstrates low-level metabolic activity on PET. A transthoracic CT-guided needle biopsy of the right upper lobe lesion was subsequently performed. Specimens obtained by fine-needle aspiration were used for cytologic examination; core specimens were used for histologic analysis. The pathology was consistent with bronchoalveolar carcinoma of a mucinous subtype.Discussion