Ewing sarcoma

What it means

A malignant tumor of the bone which always arises in the medullary tissue, occurring more often in cylindrical bones.

Histologically, Ewing's sarcoma is composed of a homogeneous population of small round cells with high nuclear to cytoplasmic ratios that are arrayed in sheets. There is scant cytoplasms, which is pale, vacuolated and characterized by faded boundaries. In contrast, the nuclei are clearly visualized by their intense color. Mitotic activity is typically low.

Rare diseases that can present with this2

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Ewing's sarcoma