Den Hartog Taylor, Whitman Carol, Brozik Michael
University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota.
Surgical Institute, Sioux Falls, South Dakota.
S D Med. 2020 Apr;73(4):150-151.
Schwannomas are benign neurogenic tumors that make up less than 1 percent of all gastrointestinal tumors. Schwannoma can occur along peripheral nerves anywhere throughout the body. Gastrointestinal schwannoma is relatively rare and most commonly occurs in the stomach, small intestine, and colon, respectively. There have only been a handful of case reports describing appendiceal schwannomas. Approximately 30-50 percent of appendicular tumors show clinical symptoms and signs similar to those of appendicitis.
A 36-year-old male presented initially for right lower quadrant pain of one day duration. He denied any other associated symptoms. CT imaging of abdomen and pelvis showed a fluid-filled and dilated appendix with fat stranding consistent with appendicitis. He underwent laparoscopic appendectomy without complication. The pathology report showed a well-defined proliferation of bland uniform cells that contained small smooth nuclei and abundant foamy cytoplasm at the tip of the appendix. Scattered eosinophils were noted. These neoplastic cells were positive for S100 and negative for CD68, CD34, and CD117, most consistent with a schwannoma.
Diagnosing appendiceal schwannoma pre-operatively is a challenging task due to the rare nature of the tumors and the lack of clinical features to separate it from other appendiceal pathology. Appendiceal schwannomas are benign but it is unclear if malignant transformation is possible if left untreated. While there are currently no agreed upon treatment guidelines for appendiceal schwannoma, it is currently thought that complete surgical resection is the best treatment while chemotherapy and radiotherapy are not effective.
施万细胞瘤是良性神经源性肿瘤，在所有胃肠道肿瘤中占比不到1%。施万细胞瘤可发生于全身任何部位的周围神经。胃肠道施万细胞瘤相对罕见，最常见于胃、小肠和结肠。仅有少数病例报告描述阑尾施万细胞瘤。约30% - 50%的阑尾肿瘤表现出与阑尾炎相似的临床症状和体征。
一名36岁男性最初因持续一天的右下腹疼痛就诊。他否认有任何其他相关症状。腹部和盆腔CT成像显示阑尾充满液体且扩张，伴有脂肪条索，符合阑尾炎表现。他接受了腹腔镜阑尾切除术，未出现并发症。病理报告显示阑尾尖端有界限清楚的温和一致细胞增生，这些细胞含有小的光滑细胞核和丰富的泡沫状细胞质。可见散在的嗜酸性粒细胞。这些肿瘤细胞S100阳性，CD68、CD34和CD117阴性，最符合施万细胞瘤。
由于阑尾施万细胞瘤罕见且缺乏将其与其他阑尾病变区分开来的临床特征，术前诊断阑尾施万细胞瘤是一项具有挑战性的任务。阑尾施万细胞瘤是良性的，但不清楚如果不治疗是否可能发生恶变。虽然目前对于阑尾施万细胞瘤尚无一致认可的治疗指南，但目前认为完整的手术切除是最佳治疗方法，而化疗和放疗无效。
