Malignant perivascular epithelioid cell tumor of the colorectum: Clinicopathological characterization, diagnosis and treatment process of 7 cases

Table 1 Clinical features of seven malignant perivascular epithelioid cell tumors in the colorectum

Case No.	Age in years	Sex	BMI in kg/m2	Basic disease	Family history	TSC	Initial site	Size in cm	Clinical presentation
1	49	Male	27.6	None	None	None	Sigmoid colon	5.5 × 4.5 × 2.5	Difficulty in defecation
2	73	Female	19.4	Hypertension	None	None	Descending colon	10.5 × 6.5 × 2.5	Palpable abdominal mass
3	30	Male	22.5	None	None	None	Ascending colon	3.0 × 2.5 × 2.0	None2
4	67	Female	21.4	Viral hepatitis	None	None	Rectum	4.0 × 2.5 × 2.0	Hematochezia
5	5	Female	18.1	None	None	None	Ascending colon	4.0 × 3.0 × 2.5	Abdominal mass and pain
6	48	Male	24.0	None	Carcinoma1	None	Transverse colon	7.7 × 6.3 × 4.0	Palpable abdominal mass
7	28	Male	19.9	None	None	None	Middle rectum	6.5 × 6.5 × 4.5	Hematochezia

¹Mother had lung carcinoma.

²The patient had no clinical presentation.

BMI: Body mass index; TSC: Tuberous sclerosis complex.

Table 2 Microscopic and immunohistochemical findings of the 7 cases

Findings	Positive/total	Percentage	Findings	Positive/total	Percentage
Tumor size > 5 cm	4/7	57.1	SMA	3/6	50.0
High nuclear grade	3/7	42.9	MiTF	3/5	60.0
Infiltrative growth	5/7	71.4	TFE3	1/7	14.3
Vascular invasion	4/7	57.1	Desmin	3/7	42.9
Necrosis	2/7	28.6	S100	1/6	16.7
Mitosis > 1/50 HPF	3/7	42.9	CD117	1/7	14.3
Pan-cytokeratin	0/5	0	CD34	0/5	0
HMB45	6/7	85.7	CD10	0/5	0
Melan A	5/7	71.4	Myo D1	1/7	14.3

HPF: High power field.