Findings

There is a monotonous sheet of small round blue cells with hyperchromatic nuclei and scant cytoplasm that is clear due to the presence of abundant glycogen.

Impression

Ewing Sarcoma

Clinical Pathologic Correlation
This is a tumor composed of anaplastic small blue cells. It presents most commonly in males <15 years old. It is extremely aggressive with early metastasis but responds well to chemotherapy (ex. Dactinomycin). Characteristic “onion-skin” appearance in bone appearing most commonly in the diaphysis of the pelvis, long bones, scapula, and ribs.

Pathology Pointer

Associated with chromosomal translocation t(11;22).

Preparation

Fixed, H & E stain

View

Light micrograph

Specimen

Tumor tissue

Image Credit

Katsumi M. Miyai, M.D., Ph.D
Department of Pathology
School of Medicine
University of California, San Diego