An isolated neurofibromal polyp of the colon

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.

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.

Neurofibroma of the Colon: A Diagnostic Mimicker of Gastrointestinal Stromal Tumor

Gastrointestinal neurofibroma usually develops as diffuse gastrointestinal involvement in neurofibromatosis type 1 patients. Only 4 cases of sporadic colonic neurofibroma in a patient without neurofibromatosis type 1 have been reported in the English literature. A 26-year-old female patient underwent colonoscopy, and a 4-cm-sized polypoid mass was identified in the sigmoid colon. Wedge resection of the mass showed a yellowish, hard submucosal tumor. Microscopically, the tumor was composed of wavy spindle cells, fibroblasts, and strands of collagen; the stroma showed scattered myxoid areas. The differential diagnoses included gastrointestinal stromal tumor, schwannoma, and neurofibroma. Immunohistochemistry for c-Kit, DOG (discovered on gastrointestinal stromal tumors)-1, smooth muscle actin, S-100 protein, and CD34 was performed. The tumor cells were diffusely positive for CD34 and S-100 protein, while they were completely negative for c-Kit, DOG-1, and smooth muscle actin. The final diagnosis was neurofibroma. Sporadic colonic neurofibroma is very rare. Given the diffuse positivity for CD34 and its rarity, colonic neurofibroma can be easily misdiagnosed as gastrointestinal stromal tumor. Recognition of this entity would be beneficial for pathologists to avoid misdiagnosis and unnecessary treatment.

[Solitary Neurofibroma of the Sigmoid Colon Presenting as a Subepithelial Tumor Successfully Removed by Endoscopic Resection]

Neurofibromas are benign, slow-growing nerve sheath tumors of the peripheral nervous system, arising from Schwann cells, and classically associated with neurofibromatosis type 1 (Nf1, von Recklinghausen's disease). They occur rarely in the gastro-intestinal tract as isolated neoplasms, outside the classical clinical feature of neurofibromatosis. We herein present an isolated colonic neurofibroma without any systemic signs of neurofibromatosis. A 59-year-old female came to our hospital for constipation. On physical examination, general appearance showed no definite skin lesions. A subepithelial tumor measuring 0.8 cm was detected at the distal descending colon on colonoscopy. The lesion was removed completely by endoscopic resection. Microscopic examination showed proliferation of spindle cells in the mucosa and infiltration of inflammatory cells. Immunohistochemical staining was positive for S-100 protein. The above morphological and immunohistochemical characteristics were consistent with a diagnosis of a solitary neurofibroma of the sigmoid colon.

Incidental finding of isolated colonic neurofibroma

Neurofibromatosis is a genetic disorder manifested by characteristic cutaneous lesions called neurofibromas. There are two distinct neurocutaneous syndromes named neurofibromatosis type 1 (also called von Recklinghausen disease or NF1) and neurofibromatosis type 2 (NF2). NF1 is by far the most common presentation and is caused by an autosomal dominant mutation in the NF1 gene mapped to chromosome 17q11.2. The literature shows that gastrointestinal involvement is noted in systemic neurofibromatosis in up to 25% of patients, but isolated intestinal neurofibromatosis is a very rare manifestation. We herein present the case of a 70-year-old woman who was diagnosed with an isolated colonic neurofibroma without any systemic signs of neurofibromatosis; only a few case reports of this condition have been published to date.

Mucosal schwann-cell hamartoma diagnosed by using an endoscopic snare polypectomy

Colorectal polyps of mesenchymal origin are a rare group of colorectal disorders. A "mucosal Schwann-cell hamartoma," which is one type of polypoid lesion that originates from the mesenchyme, is a newly-proposed disease entity to be distinguished from the neurofibromas found in type-1 neurofibromatosis. This lesion is composed of pure Schwann-cell proliferation in the lamina propria and shows diffuse immunoreactivity for the S-100 protein. We report a case of a polypoid lesion of the colon with the features of this recently-proposed disease entity.

Solitary neurofibroma of the frontal sinus

Isolated or solitary neurofibromas of the paranasal sinuses are rare. Mostly, they involve the maxillary sinus and so far, a solitary neurofibroma of the frontal sinus has never been reported in the literature. We present a case of frontal sinus neurofibroma treated successfully with surgical excision. A 28-year-old male presented with forehead swelling and computed tomography images revealed a tumor involving the left frontal sinus. Histopathological examination showed the tumor to be a neurofibroma. We discuss the clinical and pathological characteristics of neurofibroma arising in the nasal cavity and paranasal sinuses.