A Case Report of Malignant Perivascular Epithelioid Cell Tumors of the Uterus and Literature Review

Figures & data

Table 1 Classifications and Sites of Onset of PEComas

Classifications	Sites
Angiomyolipoma (AML)	Kidney, liver, spleen, heart, vagina, ovary, spermatic cord, palate, nose, mediastinum, retroperitoneum, and gastrointestinal tract
Lymphangioleiomyomatosis (LAM)	Lung, lymph nodes, lymphatics, uterus
Clear cell sugar tumor (CCST)	Pulmonary, pancreas, breast, uterus, bone, heart, and vulva
Other PEComas
Clear cell myomelanocytic tumor (CCMMT)	Falciform ligament/ligamentum teres, soft tissue of thigh, abdominal wall
PEComas-NOS	Uterus, retroperitoneum, stomach, jejunum, colon, rectum, pancreas, common bile duct, retroperitoneum, urinary bladder, oral cavity, nose, orbit, laryngopharynx, pericardium, rib, skull base, soft tissue of the thigh, upper limb, abdominal wall, skin, and bone

Figure 1 The locations of the tumor on transvaginal ultrasound apparatus (A, white arrows) and Color Doppler flow imaging (CDFI) results (B–D), red and light blue arrows).

Figure 2 Hematoxylin and eosin (H&E) staining ((A): 100 ×, (B) 200 ×). Red arrows indicate the nested pattern of tumor cells around capillaries, blue ones indicate the apoptosis of tumor cells, and the yellow indicate the spindled cells.

Figure 3 The tumor cells showed immunohistochemical positivity for Melan-A (A) and Desmin (B).

Figure 4 The location and TWI signal ((A): T2WI, (B) T1WI) of the tumor on MRI. The red arrows indicate the locations of the tumor.

Figure 5 Multiple thin-walled cysts in both lungs on different sections of CT (A and B), which were 10–30 mm in size, rounded, and devoid of internal structure. The red arrows indicate the locations of cysts.

Figure 6 Macroscopic view of the uterus, bilateral adnexa and bilateral pelvic lymph nodes. The yellow arrow indicates the involved lymph nodes (A). The red arrow indicates the tumor’s original location (A and B).

Table 2 Classification of Uterus PEComa

Classification	Criteria
Benign	No worrisome features (Size<5 cm, noninfiltrative, non–high nuclear grade and cellularity, mitotic rate ≤1/ 50 HPF, no necrosis, no vascular invasion)
Uncertain malignant potential	1) Nuclear pleomorphism/multinucleated giant cells only or 2) Size>5cm only
Malignant	Two or more worrisome features 1) Size>5 cm 2) Infiltrative 3) High nuclear grade and cellularity 4) Mitotic rate ≥1/50HPF 5) Necrosis 6) Vascular invasion