Mucinous versus nonmucinous solitary pulmonary nodular bronchioloalveolar carcinoma: CT and FDG PET findings and pathologic comparisons

We aimed to evaluate the CT, PET, and pathologic findings of solitary pulmonary nodular mucinous and nonmucinous bronchioloalveolar carcinomas (BACs). From August 2003 to March 2008, we saw 24 patients with solitary pulmonary nodular mucinous (n = 6) or nonmucinous (n = 18) BACs that were resected. CT and PET findings of the lesions were assessed in terms of size, solidity, morphologic characteristics, attenuation and maximum standardized uptake value (mSUV). All nonmucinous BACs appeared as a pure ground-glass opacity (GGO) nodule, whereas mucinous BACs appeared as solid (n = 4) or part-solid (n = 2) nodules. CT attenuation values were significantly higher for mucinous BACs (-21.0 HU ± 4.9) than for nonmucinous BACs (-491.8 HU ± 172.5) (P < .001). Mean mSUVs were 2.3 ± 1.9 for mucinous BACs and 0.5 ± 0.8 for nonmucinous BACs (P = .007), but mSUVs were not statistically different after size adjustment (r = 0.371, P = .081). Mucinous BACs appear as solid or part-solid nodules at CT, whereas nonmucinous BACs present as pure GGO nodules. Both subtypes of tumors show scant FDG uptake at PET.