Question

A diaphyseal tumor, probably small round blue cells. Which test/translocation is useful for diagnosis?

• A. T11,22
• B. T15,17

Hint:

The T(11;22)(q24;q12) translocation is a hallmark of Ewing's sarcoma, a common malignancy in children and adolescents.

Answer 1

The Correct Option is A

To diagnose a diaphyseal tumor characterized by small round blue cells, understanding the genetic translocations associated with specific tumor types is crucial. The most relevant test involves identifying chromosomal translocations that are characteristic of particular tumors.

In this case, the presence of small round blue cells suggests the possibility of Ewing's sarcoma, a type of bone cancer commonly affecting the diaphyseal region of long bones. Ewing's sarcoma is typically associated with a specific genetic translocation.

Translocation: The hallmark genetic translocation involved in Ewing's sarcoma is t(11;22)(q24;q12). This translocation results in the fusion of the EWSR1 gene on chromosome 22 to the FLI1 gene on chromosome 11, forming the EWS-FLI1 fusion protein, which plays a crucial role in the oncogenesis of Ewing's sarcoma.

Conclusion: The correct test for diagnosing a diaphyseal tumor with small round blue cells, likely indicating Ewing's sarcoma, is identifying the t(11;22) translocation.