Non-Hodgkin Lymphoma Containing Low Attenuation Area at Enhanced CT: Correlation with Histopathologic Typing

PURPOSE: To evaluate the frequently of low ahetenuation area in enhanced CT scans of non-Hodgkin lymphoma(NHL) and to find out if there is any pertinent relationship between this and the histopathologic classification. MATERIALS & METHODS: The authors reviewed CT scans in the newly diagnosed 53 patients with NHL. We defined the-low attenuation area as the one with CT attenuation value lower than that of the muscle, surrounding lesion, or other lymph nodes after contrast enhancement. NHL with the low attenuation areas were correlated with the histopathologic findings according to the classification based on the Working Formulation and the frequency of the lesion was evaluated. RESULT: Of the 53 patients, the low attenuation area was found in 13 patients (25%) at CT. The histopathologic classification could be made in 12 patients, among whom one patient was classified as low grade, six as intermediate grade, and five as high-grade. Concerning the specific cell typing, the diffuse large cell type was most common in intermediate-grade NHL seen in five patients and the large cell, immunoblastic type was most common in high-grade NHL seen ih three patients. CONCLUSION: The authors concluded that the low attenution area within lymphoma is not an infrequent finding at CT, and there was no stastistically significant correlation between this finding and the prognostic grading of the Working Formulation.