Pulmonary dirofilariasis: computed tomography findings and correlation with pathologic features.

OBJECTIVE

The purpose of this study was to describe the computed tomography (CT) and pathologic features of 5 nodules of pulmonary dirofilariasis in 4 patients.

METHODS

Four patients with 5 nodules of pathologically confirmed pulmonary dirofilariasis who under went CT were enrolled, and the imaging interpretations were retrospectively compared with the histopathologic characteristics.

RESULTS

Three of the 4 patients had a solitary nodule, and the remaining patient had 2 nodules. All the nodules were distributed in the right lower lobe and were attached to the pleura. They were all round or oval in shape and ranged in size from 11 to 22 mm in largest diameter (mean=17 mm). On thinner section CT, the nodules had a well-defined smooth margin with or without a shallow notch; they were connected to the arterial branch and, occasionally, to the venous branch. On contrast-enhanced CT, all the nodules contained a homogeneous low-attenuation area, which corresponded to areas of coagulative necrosis on histopathologic examination.

CONCLUSION

Although the CT findings of a pulmonary dirofilariasis nodule are nonspecific, awareness of the findings on contrast-enhanced CT and the pathologic appearance of this rare benign condition may facilitate its differentiation from a malignant nodule.