Neuroblastoma is a tumor that arises from embryonic neural crest tissue. It is the most common tumor diagnosed in children under the age of five. Since it arises from nerve tissue, it can be found in many locations throughout the body and therefore can be found in several body fluids.
This image shows a tumor clump in the pleural fluid of a patient with stage IV neuroblastoma. Like many of the other metastatic tumors shown in this section, the cells are large in size with a large nucleus and a soft, fine chromatin pattern with prominent nucleoli. The cytoplasm is basophilic with little distinction between individual tumor cells. Since the nuclei are so close to one another, the cytoplasm is much more scant, indicating that this is a tumor and not a mesothelial clump.