Malignant Phyllodes Tumor in an Adolescent Female: A Rare Case Report and Review of the Literature

Table 2

Grading system for phyllodes tumors based on 2012 World Health Organization classification.

Histologic features	Histological type
	Benign	Borderline	Malignant
Stromal cellularity	Mild	Moderate	Marked
Stromal atypia	Mild	Moderate	Marked
Mitosis (per 10 HPF)	<5	9-may	≥10
Stromal overgrowth	Absent	Absent or focal	Present
Tumor margin	Clear	Clear or infiltration	Infiltration

HPF: high-power field. Table adopted with permissions from Zhang and Kleer [34].