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, 6th 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.