Soft tissue tumor
If it appears fatty, gross and evaluate as a lipomatous tumor.
Generally sample one slice per centimeter.
In case of spindle cell tumors (having elongated nuclei), the following features may help to roughly classify the tumor:
- Pointed on both ends: True fibroblastic tumors
- Pointed on one end and blunted on the other ("bullet-shaped"): Neural/nerve sheath tumors (see section below)
- Blunted on both ends ("cigar-shaped"): Smooth muscle tumor
- Triangular: Myofibroblastic
In uncertain cases, the following immunohistochemistry markers are usually helpful:
- CD34, indicating a solitary fibrous tumor
- S100, indicating a neural or nerve sheath tumor (see section below)
- Desmin, indicating a muscular tumor (skeletal muscle or Smooth muscle tumor)
- Beta catenin, indicating fibromatosis
Neural or nerve sheath tumors
Further information: Evaluation of suspected malignancies