《Slide 153.》Rhabdomyosarcoma, Soft tissue
　

A. Brief Descriptions：

1. The most common soft tissue sarcoma of children.

2. Predominantly in infants and children, and rare in patient older than 40 years.

3. Predominant in the head and neck, genitourinary tract and retroperitoneum, and the extremities.

B. Gross Findings：

1. Multi-nodular, or polypoid with a glistening, gelatinous, gray-white surface.

C. Micro Findings：

1. Embryonal rhabdomyosarcoma.

2. Consist of sheets of both malignant round and spindle cells in a variably myxoid stroma.

3. The rhabdomyoblasts are large and round and have abundant eosinophilic cytoplasm.

D. Others:

Four histological categories:

1. Embryonal rhabdomyosarcoma.

2. Botryoid rhabdomyosarcoma (variant of embryonal type).

3. Alveolar rhabdomyosarcoma.

4. Pleomorphic rhabdomyosarcoma.

E. Reference：

1. Robbins Pathologic Basis of Disease, 6^th ed.  P1265-1266.

　

 

 

【 Fig. 153-1 (LP)】Composed of malignant small round cells.

　

 

　

 

【 Fig. 153-2 (LP)】The rhabdomyoblasts are large and round and have abundant eosinophilic cytoplasm.

　

 

 

【 Fig. 153-3 (LP)】