Isolated Neurofibroma of the Sigmoid Colon: a Case Report and Review of the Literature

Isolated Rectal Neurofibroma: A Case Report and Literature Review

Neurofibromas are considered benign peripheral nerve sheath tumors containing Schwann cells, fibroblasts, and perineurial cells. They are commonly associated with familial disorders. Isolated colonic neurofibromas are very rare. In this report, we discuss a case of a patient who presented to the gastroenterology clinic with a week-long occurrence of abdominal pain and bleeding. She underwent a colonoscopy in which three sentinel polyps of benign appearance, ranging in size from 4 mm to 10 mm, were removed during the procedure. The pathology report indicated that the distal rectal polyp contained a submucosal neurofibroma with SOX10+, desmin-, CD117-, DOG1-, CD34+. While NF1-associated neurofibromas harbor the risk of malignant transformation into malignant peripheral nerve sheath tumors (MPNSTs), the malignancy potential for isolated colonic neurofibromas remains uncertain due to their rarity. The clinical significance of isolated colonic neurofibromas is yet to be defined; therefore, the optimal management strategy remains uncertain. Close monitoring is advocated to both exclude the possibility of neurofibromatosis and be vigilant about the risk of malignant transformation.

Isolated colonic neurofibroma, a rare tumor: A case report and review of literature

BACKGROUND

Neurofibromas are tumors comprised of peripheral nerve sheath and connective tissue components. They can occur sporadically or as part of familial syndromes such as neurofibromatosis type 1. Isolated colonic neurofibroma without systemic manifestations is a rarely reported clinical entity. Here we present a case of a 51 years old male with an isolated colonic neurofibroma seen on a screening colonoscopy.

CASE SUMMARY

Fifty-one years old male who was otherwise healthy without a significant family history of cancer underwent a screening colonoscopy and was found have a 2.3 cm × 1.4 cm lesion in the colon. Tissue biopsy revealed a spindle cell tumor. Magnetic resonance imaging of the pelvis was negative for adenopathy. He underwent an endoscopic ultrasound that showed an ill-defined avascular lesion of mixed echogenicity measuring 2.8 cm × 15.2 cm in the submucosa with no communication with muscularis mucosa or propria. Immunohistochemistry staining of the tumor was strongly positive for S100, with rare penetrating axons deep within the tumor. Tumor cells were negative for c-kit and desmin and had low Ki-67 index. These findings were consistent with a solitary colonic submucosal neurofibroma. A detailed history and physical examination did not reveal any evidence of extraintestinal neurofibromatosis. He underwent transanal surgical resection of the tumor. The patient tolerated the procedure well without any complications.

CONCLUSION

While neurofibromas have been well described in literature, an isolated colonic neurofibroma is a rare pathological entity. Malignant transformation of neurofibromas has been reported in patients with neurofibromatosis syndromes. We report a case of isolated colonic neurofibroma and highlight the importance of resection due to the increased risk of tumorigenesis.

Sporadic neurofibroma of transverse colon in a patient without neurofibromatosis type 1: A case report

Introduction

The occurrence of sporadic colonic neurofibroma particularly in a patient without neurofibromatosis type 1 has been rarely reported. Therefore, the clinical significance of this disease has not been fully elucidated.

Presentation of case

An 81-year-old woman with a positive fecal occult blood test result was referred to our institution for the evaluation of anemia. On colonoscopy, a 50-mm submucosal tumor-like mass was found in the hepatic flexure of the colon. Superficial biopsy and boring biopsy showed unspecific granulation tissues, and immunostaining revealed that the mesenchymal tumor was negative for CD34, c-kit, desmin, and S100 protein. The patient underwent laparoscopic right colectomy with complete mesocolic excision (CME). Pathologically, the tumor was diagnosed as neurofibroma.

Discussion

Gastrointestinal neurofibromas are known to cause clinical symptoms. No colonic neurofibroma has been diagnosed before resection. Moreover, neurofibromas, particularly large lesions, reportedly undergo malignant transformation. Surgical extirpation with clear margins is the primary treatment, and laparoscopic surgery is considered acceptable for colonic neurofibroma and colon cancer.

Conclusion

Based on our experience, a preoperative diagnosis was impossible for colonic neurofibroma. Laparoscopic surgery with CME is considered feasible for sporadic colonic neurofibroma.

Spindle cell proliferations of the sigmoid colon, rectum and anus: a review with emphasis on perineurioma

A wide range of spindle cell proliferations are found uncommonly in the sigmoid colon, rectum and anus. They usually present as polyps, and include reactive lesions and benign and malignant neoplasms which may be primary or metastatic. They are less frequently described in the literature compared to those in the upper gastrointestinal tract, and may be underdiagnosed. The widespread use of sigmoidoscopy in symptomatic patients and bowel cancer screening programmes means that histopathologists must be aware of, and adopt a logical approach to, diagnosing spindle cell proliferations in biopsy and polypectomy specimens. This is particularly relevant given the strong association of some mesenchymal polyps with hereditary cancer syndromes. This review article will focus on perineurioma and the recent debate in relation to its overlap with fibroblastic polyp. The clinical, endoscopic, histological and immunohistochemical features of spindle cell proliferations which should be considered in the differential diagnosis of perineurioma will be discussed. There is also a brief reference to malignant spindle cell tumours of diagnostic importance.

Isolated colonic neurofibroma in the setting of Lynch syndrome: A case report and review of literature

BACKGROUND

Gastrointestinal neurofibromas are commonly found in patients diagnosed with neurofibromatosis type 1. However, isolated gastrointestinal neurofibromas are a rare entity and only fourteen cases of isolated colorectal neurofibromas have been documented in literature. Isolated gastrointestinal neurofibromas have not been associated with Lynch syndrome (LS). Patients with LS are at an increased risk of colorectal cancer, and are recommended to undergo screening colonoscopy.

CASE SUMMARY

A 33-year-old healthy female with a family history of LS was found to have unresectable polyp in the ascending colon on screening colonoscopy suspicious for malignancy. The patient was asymptomatic and had no stigmata of neurofibromatosis. A staging workup for colorectal cancer revealed no evidence of metastatic disease. A discussion with the patient resulted in the decision to undergo a segmental resection with ongoing surveillance. The patient underwent a laparoscopic right hemicolectomy. Histopathology was consistent with a gastrointestinal neurofibroma. Post-operatively, the patient recovered well. She will not require further treatment with regards to her colonic neurofibroma, but will continue to follow-up for ongoing surveillance of her LS.

CONCLUSION

We present the first case of an isolated colonic neurofibroma in a patient with LS. This case explores considerations for the management of isolated gastrointestinal neurofibromas given the lack of guidelines in literature.