This tumor should not be confused with the prostatic stromal tumor of uncertain malignant potential which may be abbreviated the same way (STUMP).
The Bell criteria were developed to help categorize them and differentiate them from their main differential diagnoses, leiomyosarcoma and uterine leiomyoma.
Evaluation of the mitotic figures in a STUMP requires evaluation of 3 specific criteria Coagulative tumor cell necrosis is common in clinically malignant smooth muscle cell tumors.
If dead nuclei present, they are uniform and the chromatin is often.
Necrosis secondary to ulceration in submucous leiomyomas features acute inflammatory cells and a peripheral reparative process, whereas ghost outlines of nuclei are usually inconspicuous or absent.