OBJECTIVE: We retrospectively reviewed CT and pathologic examinations in resected nodular bronchioloalveolar carcinomas (BACs) to correlate the histology with the appearance of the nodules on preoperative thin section CT images. MATERIALS AND METHODS: Thin section CT scans of 11 patients with nodular BAC were reviewed by two observers. In each case, size, tumor-lung interface, and internal characteristics of the nodule were recorded and correlated with histopathologic examinations. RESULTS: Computed tomography showed a large bronchus leading to or contained within the nodule in 36%; spiculated, lobulated, or irregular borders in 82%; pleural retraction in 36%; internal inhomogeneity in 45%; and a zone of intermediate attenuation surrounding a higher attenuation nodule and separating it from the surrounding lung parenchyma (the CT halo sign) in 18% of the 11 BACs. In two lesions internal serpentine radiolucencies could be seen. Histopathologic studies showed this correlated with the air-containing glandular spaces of the tumor. CONCLUSION: The CT halo sign and serpentine radiolucencies should be added to the list of the CT findings of nodular BAC. However histologic examination is required to confirm the diagnosis of BAC.
OBJECTIVE: We retrospectively reviewed CT and pathologic examinations in resected nodular bronchioloalveolar carcinomas (BACs) to correlate the histology with the appearance of the nodules on preoperative thin section CT images. MATERIALS AND METHODS: Thin section CT scans of 11 patients with nodular BAC were reviewed by two observers. In each case, size, tumor-lung interface, and internal characteristics of the nodule were recorded and correlated with histopathologic examinations. RESULTS: Computed tomography showed a large bronchus leading to or contained within the nodule in 36%; spiculated, lobulated, or irregular borders in 82%; pleural retraction in 36%; internal inhomogeneity in 45%; and a zone of intermediate attenuation surrounding a higher attenuation nodule and separating it from the surrounding lung parenchyma (the CT halo sign) in 18% of the 11 BACs. In two lesions internal serpentine radiolucencies could be seen. Histopathologic studies showed this correlated with the air-containing glandular spaces of the tumor. CONCLUSION: The CT halo sign and serpentine radiolucencies should be added to the list of the CT findings of nodular BAC. However histologic examination is required to confirm the diagnosis of BAC.