Neuroblastoma : Differentiating
Differentiating subtype of neuroblastomas have abundant neuropil and more than 5% of tumor cells show differentiation toward ganglion cells. Differentiating neuroblasts have moderate to abundant acidophilic or amphophilic cytoplasm and an enlarged eccentric vesicular nucleus with a single prominent nucleolus. The image shows lobules of differentiating neuroblasts completely or incompletely separated by delicate fibrovascular septa which usually contain S-100 protein positive Schwann cells or Schwannian blasts. Abundant neuropil and scattered foci of calcification are also present. There is a histologic overlap between differentiating neuroblastoma and ganglioneuroblastoma.