《Slide 151.》Leiomyosarcoma, Soft tissue
　

A. Brief Descriptions：

1. Adult, female (64%), lower extremity, subcutaneous.

B. Gross Findings：

1. Well-circumscribed (infiltrate microscopically), larger, softer with necrosis, hemorrhage, and cystic degeneration.

C. Micro Findings：

1. Malignant spindle cells: elongated, blunt-ended nuclei and acidophilic, fibrillary cytoplasm.

2. Growth in interlacing cords, with palisading of nuclei.

3. Nuclear atypia, large bizarre nuclei or pyknotosis.

4. High mitotic activity (>20/50 HPF).

5. Some round cells with clear space surrounding nucleus.

D. Others:

1. What is GIST (gastrointestinal stromal tumor) ?

2. What is epitheliod leiomyosarcoma ?

E. Reference：

1. Robbins Pathologic Basis of Disease, 6^th ed.  P1266.

　

 

 

【 Fig. 151-1 (LP)】 Interlacing of spindle cells without any special arrangement.

　

 

 

【 Fig. 151-2 (LP)】 Spindle cells with elongated blunt-end nuclei.

　

　

 

【 Fig. 151-3 (LP)】 Spindle cells with elongated, blunt-end nuclei; note high mitotic activity.