Endoscopic ultrasound-guided fine-needle aspiration cytology of peripheral nerve-sheath tumors

Endoscopic ultrasound (EUS) has allowed for the fine-needle aspiration and diagnosis of many different gastrointestinal neoplasms, including mesenchymal tumors. Although most mesenchymal tumors of the gastrointestinal tract are gastrointestinal stromal tumors (GISTs), other mesenchymal tumors, including neural tumors, do occur. Proper diagnosis and differentiation of these tumors from GISTs are important because of their different prognoses and treatment regimens. We encountered three peripheral nerve-sheath tumors of the gastrointestinal tract aspirated by EUS (two schwannomas and a granular-cell tumor). We report on the endoscopic ultrasound, cytologic, histologic, and immunohistochemical findings of these cases.     

Neurogenic polyps

A neoplastic proliferation of peripheral nerve sheath cells (Schwann cells, fibroblasts and perineurial cells) and ganglion cells in the colorectum may give rise to the mucosal or submucosal polyps. Depending upon the predominant cell types, these neurogenic polyps can be classified as schwannomas, granular cell tumours, neurofibromas, perineuriomas, mixed nerve sheath tumours, ganglioneuromas or paragangliomas. Morphologically, the neoplastic cells repeat or mimic the corresponding nerve sheath cells or neurons in terms of growth pattern, histology and immunoreactivity. They are uncommon, but the polyps can occur in any age group, although the vast majority of patients are adults. The polyps can be either solitary (most peripheral nerve sheath tumours) or multiple, especially if associated with systemic diseases (i.e. syndromes involving the peripheral nerve tissue). They are usually incidental findings or may be accompanied by gastrointestinal symptoms. Almost all colorectal neurogenic polyps are benign, and they rarely undergo malignant transformation unless they are part of a syndromatic manifestation. However, these polyps may cause a diagnostic problem during screening for colorectal cancer. An accurate diagnosis of these entities will help clinicians to make appropriate management decisions.     

Schwannoma of the nasal septum: a case report with review of the literature

Schwannomas are neurogenic neoplasms rarely found in the sinonasal tract, where localization to the nasal septum is exceedingly rare (only 11 cases have been described in the western literature). We report the case of a 29-year-old white male with a schwannoma completely filling the left nasal fossa and arising from the bony part of the septum. A computer tomography (CT) scan and a biopsy suggestive of benign schwannoma were obtained before the lesion was removed by a degloving approach. The preoperative diagnosis of nasal septum schwannoma was confirmed. The patient is asymptomatic and without endoscopic evidence of recurrence 7 years after surgery. A review of the literature with particular emphasis on the clinical presentation, histological features, differential diagnosis and therapeutic options for such a rare lesion is included. Received: 11 June 1999 / Accepted: 10 February 2000     

Surgical Findings in Idiopathic Trigeminal Neuropathy Mimicking a Trigeminal Neurinoma

Summary  Idiopathic trigeminal neuropathy is a benign disorder where the main clinical feature is facial numbness limited to the territory of one or more divisions of the trigeminal nerve, persisting for a few weeks to several years and in which no underlying disease can be identified. The case of a 37-year-old man with a brief history of sensory and motor trigeminal symptoms who showed magnetic resonance imaging (MRI) findings consistent with a small trigeminal neurinoma is reported. The patient was operated on but no tumour could be found during surgery and a biopsy was taken from the portio major. Pathological diagnosis was chronic non granulomatous inflammatory reaction with areas of coagulation necrosis. Control MRI showed complete resolution of the trigeminal abnormalities. It is concluded that in patients with MRI findings suggestive of a small trigeminal schwannoma, benign idiopathic trigeminal neuropathy should also be considered in the differential diagnosis. A conservative approach with sequential MRI studies may avoid an unnecessary surgical exploration.     

Should patients with asymmetrical noise‐induced hearing loss be screened for vestibular schwannomas?

Should patients with asymmetrical noise‐induced hearing loss be screened for vestibular schwannomas? The Peterborough ENT department receives many referrals for MoD personnel who have suffered hearing loss from occupational noise exposure. Those patients with asymmetrical sensorineural hearing loss are routinely screened for vestibular schwannomas by MRI scanning. Scan reports from the past 5 years have been reviewed and out of 152 scans, four revealed vestibular schwannomas giving a pick‐up rate of 2.5%, which compares favourably with other published pick‐up rates. Review of the audiograms in these cases suggests that they can be misleading in this context. The conclusion is that patients with noise‐induced asymmetrical hearing loss should be screened for acoustic neuromas.     

Clinical experience with vestibular schwannomas: epidemiology, symptomatology, diagnosis, and surgical results

The Danish model for vestibular schwannoma (VS) surgery has been influenced by some historical otological events, taking its origin in the fact that the first attempt to remove CPA tumors was performed by an otologist in 1916. In approximately 50 years VS surgery was performed by neurosurgeons in a decentralized model. Highly specialized neuro- and otosurgeons have been included in our team since the early beginning of the centralized Danish model of VS surgery in 1976. Our surgical practice has always been performed on the basis of known and proven knowledge, but we spared no effort to search for innovative procedures. The present paper reflects the experience we have gained in two decades of VS surgery. Our studies on the incidence, symptomatology, diagnosis, expectancy and surgical results are presented. Received: 26 February 1997 / Accepted: 7 July 1997     

Growth rate of non‐vestibular intracranial schwannomas

Growth rate of non‐vestibular intracranial schwannomas A group of nine patients with non‐vestibular intracranial neuromas (four jugular, four facial, one trigeminal) underwent an interval scanning management policy, with serial annual magnetic resonance (MR) imaging. Tumour volume was assessed by manual measurement of the tumour area by MR imaging. Tumour volume was assessed by manual measurement of the tumour area on MR imaging axial cuts. The mean tumour size at presentation was 4.6 cm³ (range 0.7–17.8 cm³). During a mean follow‐up of 36 months (range 22–50 months), five out of nine tumours grew significantly at a rate of more than 5% of their initial volume per year. Only those tumours growing at a rate of more than 20% initial volume per year exhibited symptom progression. During a 36‐month period of interval scanning, just over 50% of non‐vestibular intracranial neuromas exhibited significant growth. Symptom progression was found to be a strong indicator of a high growth rate. This proportion exhibiting growth is higher than that demonstrated by unilateral sporadic vestibular schwannomas, but less than in patients with neurofibromatosis II. Early treatment of non‐vestibular intracranial neuromas should therefore be considered.     

Intraosseous schwannoma of the metacarpal

Intraosseous schwannoma (neurilemmoma) is an extremely rare, benign neoplasm, constituting less than 0.2% of primary bone tumors. It infrequently involves the bones of the hand. We present a case of intraosseous neurilemmoma of the metacarpal. Received: 26 July 1999 Revision requested: 16 August 1999 Revision received: 16 September 1999 Accepted: 4 October 1999     

8例胃肠道神经鞘瘤的CT征象及误诊原因分析

目的 分析胃肠道神经鞘瘤的CT表现特征,提高对该病的认识,降低误诊率.方法 回顾性分析8例经手术病理证实为胃肠道神经鞘瘤,术前CT检查均误诊患者的影像资料,分析其CT征象及鉴别点.结果 8例患者病灶均为单发,直径为1.2～6.7 cm,中位直径为3.65 cm.7例发生于胃部,1例发生于十二指肠;5例向腔内生长,3例向腔外生长.CT平扫均表现为边界清晰、类圆形或椭圆形软组织肿块,7例密度均匀,1例见斑片状囊变区,增强扫描均呈轻度至明显渐进性强化.术前7例误诊为胃肠道间质瘤,1例误诊为平滑肌瘤.结论 胃肠道神经鞘瘤的CT征象具有一定特征性,可对部分病例做出提示性诊断;对于胃肠道壁内边缘光整、密度均匀的渐进性强化实性肿块,应考虑到神经鞘瘤的可能.     

Two giant connected retroperitoneal schwannomas: a rare case report

Schwannoma is a type of tumor originating from Schwann cells of peripheral nerves. In this study, we report a rare case of two giant connected retroperitoneal schwannomas. The patient presented to our department with a 1-day history of abdominal pain and without other symptoms. There were no abnormalities in the patient’s tumor markers. Abdominal plain computed tomography (CT) revealed two (combined) retroperitoneal masses appearing as soft tissue-density shadows with uneven internal density, cystic low-density shadows, and patchy calcification shadows. The larger mass measured approximately 12.0 cm × 12.3 cm in size. The tumors were completely excised by a reasonable surgical approach while the surrounding organs closely related to the tumor were preserved. Postoperative pathology confirmed that the tumors were benign schwannomas. In the 18-month follow-up, the patient had no recurrences and was asymptomatic. We summarize the diagnosis and treatment of two rare combined giant retroperitoneal schwannomas in a single patient. Laparotomy for the management of retroperitoneal giant schwannomas may be safe and effective.