Neuroblastoma: a specific sonographic tissue pattern.

Previous attempts to determine a sonographic appearance characteristic of neuroblastoma have had diverse results. Sonograms of 53 abdominal tumors, including 10 neuroblastomas, imaged during 1982-1986 were reviewed. Four of the patients with neuroblastoma had a distinctive sonographic "lobule" of increased echogenicity in a part of the larger tumor mass. This sonographic appearance was secondary to the growth pattern of the tumor and was not cell specific. Correlative CT scans in two of the four patients did not differentiate this lobule. Histologically, the lobule was an aggregate of uniform neuroblastoma cells (marginated by reticulin and collagen) without hemorrhage, necrosis, or calcification. This tissue pattern was not seen in any of the other 43 neoplasms, including 12 Wilms' tumors. When identified sonographically, the lobule identified in this study seems specific for neuroblastoma and is a valuable diagnostic sign in children with an abdominal mass.