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

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.

Upregulation of microRNA-132 in gastric cancer promotes cell proliferation via retinoblastoma 1 targeting.

Gastric cancer is one of the most frequent malignancies and a leading cause of cancer-related mortality worldwide. MicroRNAs (miRs), a class of small non­coding RNAs, have been shown to be critical in tumorigenesis. In the present study, the expression levels of miR­132 were analyzed in gastric cancer samples using quantitative reverse transcription­polymerase chain reaction. In addition, the cell viability, proliferation and invasion abilities were determined in two gastric cancer cell lines, NCI­N87 and MGC80­3, that were transfected with miR­132 mimics or antisense oligos. It was found that miR­132 expression was significantly upregulated in gastric cancer tissues when compared with adjacent non­cancerous tissues. At the molecular level, the data demonstrated that miR­132 inhibits the protein levels of retinoblastoma 1 (RB1) by targeting the 3'­untranslated region. Furthermore, reintroduction of RB1 markedly attenuated the proliferative roles of miR­132 overexpression. Therefore, the present results indicate that the miR­132/RB1 regulatory axis may be a potential novel diagnostic and therapeutic target for the treatment of gastric cancer.