Pediatric case of colonic perivascular epithelioid cell tumor complicated with intussusception and anal incarceration: A case report

Abstract

Background: Perivascular epithelioid cell tumor (PEComa) represents a group of rare mesenchymal tumors. PEComa can occur in many organs but is rare in the colorectum, especially in children. Furthermore, PEComa is a rare cause of intussusception, the telescoping of a segment of the gastrointestinal tract into an adjacent one. We describe a rare case of pediatric PEComa complicated with intussusception and anal incarceration, and conduct a review of the current literature.

Case summary: A 12-year-old girl presented with abdominal pain and abdominal ultrasound suggested intussusception. Endoscopic direct-vision intussusception treatment and colonoscopy was performed. A spherical tumor was discovered in the transverse colon and removed by surgery. Postoperative pathologic analyses revealed that the tumor volume was 5.0 cm × 4.5 cm × 3.0 cm and the tumor tissue was located in the submucosa of the colon, arranged in an alveolar pattern. The cell morphology was regular, no neoplastic necrosis was observed, and nuclear fission was rare. The immunohistochemical staining results were as follows: Human melanoma black 45 (HMB 45) (+), cluster of differentiation 31 (CD31) (+), cytokeratin (-), melanoma-associated antigen recognized by T cells (-), smooth muscle actin (-), molleya (-), desmin (-), S-100 (-), CD117 (-), and Ki67 (positive rate in hot spot < 5%). Combined with the results of pathology and immunohistochemistry, we diagnosed the tumor as PEComa. Postoperative recovery was good at the 4 mo follow-up.

Conclusion: The diagnosis of PEComa mainly depends on pathology and immunohistochemistry. Radical resection is the preferred treatment method.

Keywords: Anal incarceration; Case report; Colonic; Endoscopic direct-vision intussusception treatment; Intussusception; Perivascular epithelioid cell tumor.

Figure 1

Abdominal computed tomography results. A: Plain scan showed a transverse colonic mass; B: Space-occupying lesion showed obvious enhancement.

Figure 2

Colonoscopy results. A: The tumor is spherical, with a diameter of about 5 cm, a surface that is congested and eroded, and with formation of local ulcers; B The root of the tumor has a thick pedicle, with rough surface mucosa and covered with leukoplakia; C: Narrow band imaging showed that the glandular ducts had disappeared and the presence of vasodilation.

Figure 3

Tumor. A: The tumor was outside the anus; B: The tumor was removed surgically, in addition to about 3 cm of the affected bowel.

Figure 4

Pathology and immunohistochemistry results. A: 40 × magnification showing that the tumor was located in the intestinal wall, and the tumor cells were arranged in nests or acini; B: 100 × magnification showing that the tumor cells were transparent or eosinophilic granular; C: 200 × magnification showing abundant capillaries in the interstitium; D: Human melanoma black 45 (+) detected by the EnVision method.