Rhabdomyosarcoma Score in Embryonal Rhabdomyosarcoma

 

Applicable histologic types of rhabdomyosarcoma:

(1) embryonal

(2) rhabdomyosarcoma not otherwise specified

 

Parameters:

(1) degree of maturation score

(1a) amount of cytoplasm <= surface area of the nucleus: 1 point

(1b) amount of cytoplasm > surface area of the nucleus, indicating a high degree of maturation: 2 points

(2) percentage septated area: from 1 to 100

(3) percentage tumor necrosis: from 1 to 100

 

Best outcome:

(1) large amount of cytoplasm

(2) no tumor necrosis

(3) absence of septae

 

rhabdomyosarcoma score =

= (-0.27 * (degree of maturation score)) + (0.007 * (percentage septated area)) + (0.031 * (percentage tumor necrosis))

 

Interpretation:

• minimum score: -0.54

• maximum score: 3.53

• Optimal cut-off point for prognostic separation was (-0.20).

Rhabdomyosarcoma Score	Grade	2 year survival	long term survival
< - 0.2	I	84%	63%
>= -0.20	II	54%	41%