Bone & joints
Small cell osteosarcoma

Topic Completed: 1 November 2014

Revised: 28 December 2018

Copyright: (c) 2003-2018,, Inc.

PubMed Search: Small cell osteosarcoma

Nat Pernick, M.D.
Page views in 2020: 2,762
Page views in 2021 to date: 1,219
Cite this page: Pernick N Small cell osteosarcoma. website. Accessed May 16th, 2021.
Definition / general
  • Very rare
  • Poor prognosis
Microscopic (histologic) description
  • Diffuse growth of small, uniform, round/spindle tumor cells, focally produces malignant osteoid, occasionally mixed with cartilage
Microscopic (histologic) images

Small osteoblasts with indistinct cytoplasm

Lymphoma-like pattern

Small foci of osteoid

Contributed by Dr. Mark R. Wick


Positive stains
Electron microscopy description
  • High N/C ratio, poorly differentiated cytoplasm, numerous free ribosomes and mitochondria, small junctions, envelopment of individual and groups of cells by matrix (Hum Pathol 1991;22:267)
Differential diagnosis
Additional references
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