A. Osteoclastoma

Osteoclastoma:

Is a locally aggressive tumor with a monocytes macrophage lineage. Known to arise from the epiphyses of long bones. Often seen between 20-40 years and radiologically they produce a lobulated expansile osteolytic lesion with a soap bubble appearance. The giant cells seen in this tumor are not neoplastic, the neoplastic cells are the primitive  mononuclear mesenchymal stromal cells. 

History:

36-year-old male patient presented with a pain in the right knee. 

Key Questions & Answers

1.Describe the gross features of the specimen

• 1. Epiphyseal end of the humerus

  2. An expansile cystic lesion with areas of haemorrhage

2.Identify the microscopic features of the given slide

• 1. Sheets of small spindle shaped stromal cells forming the bulk of the tumor

  2. Groups of scattered large multinucleated osteoclastic giant cells

  3. Areas of hemorrhage

3.Diagnose the pathological condition correlating the history, gross and microscopic features

       Osteoclastoma (Giant-cell tumor)

4.Which is the neoplastic component of the above lesion

         Mononuclear cells (spindle shaped stromal cells)

5.What is the radiological appearance of the above lesion

      ‘Soap-bubble’ appearance