Small-cell pediatric tumors: histology, immunohistochemistry, and electron microscopy.

Histology, immunohistochemistry, and electron microscopy give an account on what is known of the correlation between histologic appearance and prognosis in this important group of tumors. Ultrastructural and immunohistochemical findings are presented that frequently are useful in establishing a diagnosis, but also serve to elucidate the histogenesis of some tumors, especially those that lack characteristic features.