Neuroblastoma and the differential diagnosis of small-, round-, blue-cell tumors.

Of the solid tumors of childhood, neuroblastoma--the prototypic small-, round-, blue-cell neoplasm--occurs in the youngest patients and has shown the least predictable biologic behavior and response to therapy. It is often confused clinically and histologically with Wilms' tumor, rhabdomyosarcoma, lymphoma, and especially, Ewing's sarcoma. Certain clinical and histologic features that may be useful in prognosis have been identified, however, and a variety of distinctive light microscopic, electron microscopic, and immunohistochemical features may be useful in differentiating this and related tumors. Many of the varied techniques useful in the differential diagnosis of these tumors can now be employed routinely in most laboratories.