Benign Schwannoma Research Articles

DIAGNOSTIC A POSTERIORI D’UN SCHWANNOME DU NERF SURAL : A PROPOS D’UNE OBSERVATION

Schwannoma is a nerve tumor developed at the expense of Schwann sheath cells. This tumor is usually benign, exceptionally malignant; it is related and sometimes associated with neurofibromatosis resulting in some clinical confusion. His diagnosis is histopathological. We report the case of a schwannoma of the leg supported in the plastic surgery department of Aristide Le Dantec hospital in Dakar. It is a 41-year-old patient presenting for ten years a tumor of the posterior aspect of the leg evoking a neurofibroma ; he underwent incomplete excision and the histopathological examination of the excision specimen concluded that there was benign schwannoma. The result was good and stable at one year. This case illustrates the clinical difficulty in differentiating neurofibromatosis and the value of incomplete excision in some cases.

Case report: schwannoma arising from the unilateral adrenal area with bilateral hyperaldosteronism

BackgroundWe report a rare case of a juxta-adrenal schwannoma that could not be discriminated from an adrenal tumor before surgical resection and was complicated by bilateral hyperaldosteronism. To the best of our knowledge, this is first case in which both a juxta-adrenal schwannoma and hyperaldosteronism co-existed.Case presentationA 69-year-old male treated for hypertension was found to have a left supra-renal mass (5.8 × 5.2 cm) by abdominal computed tomography. His laboratory data showed that his plasma aldosterone concentration (PAC) was within the normal range, but his plasma renin activity (PRA) was reduced, resulting in an increased aldosterone/renin ratio (ARR). Load tests of captopril or furosemide in the standing position demonstrated autonomous aldosterone secretion and renin suppression. Adrenal venous sampling (AVS) with ACTH stimulation indicated bilateral hypersecretion of aldosterone. A left supra-renal tumor was resected because of the possibility of malignancy and was found to be a benign schwannoma arising from the juxta-adrenal region together with an adrenal gland. The dissected left adrenal gland was morphologically hyperplastic in the zona glomerulosa, but was immunohistochemically negative for CYP11B2 (aldosterone synthase). Multiple CYP11B2-positive adrenocortical micronodules were detected in the adrenal gland, indicating micronodular hyperplasia. Although bilateral aldosteronism was indicated by AVS before the operation, the PRA, PAC and ARR values were within their respective reference ranges after resection of the unilateral tumor, suggesting that the slight increase in hormone secretion from the remaining right-sided lesion could not be detected after resection.ConclusionA clinical and morphologic diagnosis of juxta-adrenal schwannoma is difficult, particularly in a case of hyperaldosteronism, as shown in this case. These data suggest the complexity and difficulty diagnosing adrenal incidentaloma.

Rare Diagnosis of Benign Schwannomas after Right Thyroid Lobectomy in A 12-Year-Old Female

Rare Diagnosis of Benign Schwannomas after Right Thyroid Lobectomy in A 12-Year-Old Female

Endocardial Peripheral Nerve Sheath Tumour with Features of a Benign Schwannoma in a Donkey

A peripheral nerve sheath tumour, with features of a benign schwannoma and arising from the endocardium of the right ventricle, was found incidentally during routine post-mortem examination of a 28-year-old gelding donkey. Macroscopically, five round to oval, white to grey and red, firm masses, firmly attached to the endocardium were identified. Microscopically, the endocardium and adjacent subendocardium were infiltrated by a variably demarcated, non-encapsulated mesenchymal neoplasm with features of a benign schwannoma, including concurrent presence of Antoni A and Antoni B areas, nuclear palisading, neoplastic cells with enlarged bizarre nuclei ('ancient change')and the formation of Verocay-like bodies. Immunohistochemically, the tumour cells were variably strongly positive for expression of S100 and glial fibrillary acidic protein. This is the first cardiac tumour reported in a donkey and is macroscopically, histologically and immunohistochemically similar to endocardial schwannoma occurring in Wistar rats.

Schwannoma of the vagina - a common tumor but a rare location: A case report.

Schwannomas are nerve sheath tumors arising from Schwann cells. These tumors usually present as benign, relatively slow-growing, solitary, encapsulated, painless masses. Schwannomas rarely occur in the vagina, and have not been fully recognized as gynecological tumors. We herein describe the case of a patient who presented with a schwannoma occurring in the wall of vagina, with non-specific symptoms lasting for ~1 year. The vaginal mass was incidentally detected during a sonographic examination and the patient was referred for surgical resection. The surgery was uncomplicated and the vaginal tumor was diagnosed as benign schwannoma. The immunohistochemical examination revealed positivity for vimentin, S-100 and glial fibrillary acidic protein, whereas discovered on GIST-1, CD117, CD34, desmin, smooth muscle actin and cytokeratin were negative. Tumors occurring in the vagina are common and are of variable histological types, with a wide range of pathological characteristics and complications. Schwannoma should be considered in the differential diagnosis in patients presenting with atypical symptoms from the gynecological tract. Immunohistochemical staining is required for confirmation of the diagnosis of schwannoma, and for distinguishing this entity from other homologous tumors.

Sporting Injuries - An Unusual Case of a Traumatic Schwannoma Presenting on the Upper Lip of a Professional Footballer, a Case Report

Schwannomas are benign tumors that typically arise from the perineural Schwann cells responsible for the production of the insulting sheath called myelin with only 1% occurring intraorally. We present and report a rare case of a schwannoma presenting on the upper lip of a 29-year-old male professional footballer who was referred to OMFS clinic after with a persistent swelling on his upper lip following trauma to the face 1 year ago. The treatment for benign schwannoma consists of total surgical excision. However, recurrences as well as the malignant transformation are rare events. It is possible that other disorders may appear with similar clinical picture, so the need for a biopsy of the suspected lesion cannot be emphasized enough to rule out other conditions. The differential diagnoses of schwannomas include lesions such as lipomas, hemangiomas, eosinophilic granuloma, epidermoid and dermoid cysts, epithelial hyperplasia, granular cell tumour, leiomyoma, and lymphangioma. J Med Cases. 2017;8(8):243-245 doi: https://doi.org/10.14740/jmc2761w

Schwannoma in Pelvis: A Diagnostic Dilemma

Schwannoma is the most common benign nerve sheath tumors generally occurring in head and neck and extremities. Schwannomas are very rarely found in pelvic region and are often labeled as gynecological or urological masses in the preoperative workup. Here we present a 40-year-old female patient who presented with micturition difficulty. Initial evaluation by CT and MRI showed a 10-cm pre-sacral mass abutting the bladder and rectum. Biopsy revealed a benign schwannoma. Laparotomy was planned, and we found a 10 × 10 cm mass in pre-sacral space adherent to sigmoid colon, rectum, posterior wall of uterus, bilateral ureters and left internal iliac vessels. Mass was mobilized from surrounding viscera and was excised in toto. Histopathology revealed a 10 × 7×4 cm benign schwannoma. Patient recovered without any complications. Retroperitoneal schwannomas are very rare, and biopsy is required to ascertain the correct diagnosis as radiological features are non-specific. Surgical excision is the only curative option. Most cases will require simple excision or enucleation of the tumor without requirement of major visceral resections.

Schwannoma of the hypoglossal nerve: Review of the literature based on an illustrative case

Schwannomas are benign tumours that originate from the myelin sheath of peripheral nerves. They are characterised by a slow growth tendency. Benign schwannomas represent 35% of the head and neck district tumours. Hypoglossal schwannomas account for 5% of non-vestibular schwannomas, and malignant schwannomas occur very rarely. In the present case report, the case of a 49-year-old man who presented with paraesthesias in the left parotid and submandibular region, associated with sensation of foreign bodies and dysphagia for solids, is described. A clinical examination revealed the presence of an ovoid palpable mass in the lateral-cervical region of the neck. The patient subsequently underwent excisional surgery, and neuropathological evaluation of the specimen confirmed the diagnosis of benign schwannoma with Antoni areas A and B. Despite the rarity of schwannomas, this condition should be considered in differential diagnoses for masses localised in the neck, as in cases where they reach considerable sizes (>3 cm in diameter). Surgery therefore represents the first-choice treatment.

P.098 Evaluation and surgical management of pelvic peripheral nerve sheath tumors: the University of Toronto experience and review of literature

Background: Pelvic peripheral nerve sheath tumors (PNST), which includes neurofibroma, schwannoma, and MPNST, are rare tumors located in the retroperitoneum. Methods: The case records of a prospectively maintained database at Sunnybrook Health Sciences Center (SHSC) were reviewed to identify patients with pelvic PNST, managed between 2006 - 2016. Medical records were retrospectively reviewed for patient demographics, presentation, tumor location, symptoms, imaging characteristics, management, and outcome. The surgical technical caveats were described. An English language literature review was performed to describe previously published experiences. Results: The series consisted of 7 patients, ranging from 22 - 74 years of age at presentation. These lesions tend to be large at the time of diagnosis, and presenting symptoms include abdominal, flank, or back pain, as well as leg edema or hydronephrosis from local compression. Most patients in this cohort were managed surgically with midline abdominal transperitoneal exposures. Lastly, 5 tumors were benign schwannomas managed with gross total resection or debulking, while 2 patients had MPNSTs managed with biopsy followed by adjuvant chemoradiation therapy. Conclusions: In this case series, we describe the characteristics, evaluation, and management of 7 patients with pelvic PNST at a major healthcare institution in Toronto, Canada, highlighting the technical aspects of managing this rare and challenging entity.

TIM-3 plays a more important role than PD-1 in the functional impairments of cytotoxic T cells of malignant Schwannomas.

Cancer immunotherapy using cytotoxic T cells demonstrates dramatic survival benefits in lymphomas, but its efficacy in solid tumors is limited. Here, we investigated the possibility of using cytotoxic T cells to treat malignant Schwannoma, a rare but aggressive nerve sheath tumor, by examining the native T-cell immunity in the host. We found that compared to CD8+ T cells from healthy controls or benign Schwannoma patients, the CD8+ T cells from malignant Schwannoma patients were present at normal frequencies but were substantially enriched with PD-1-TIM-3+ and PD-1+TIM-3+ cells. Compared to the PD-1-TIM-3- CD8+ T cells, the PD-1-TIM-3+ and PD-1+TIM-3+ CD8+ T cells presented significantly lower proliferation capacity, reduced interleukin 2 and interferon gamma expression, and/or dramatically decreased perforin and granzyme B secretion, indicating a whole-spectrum immunosuppression and reduced cytotoxicity. TIM-3 expression alone was associated with lower proliferation and less perforin and granzyme B secretion, whereas PD-1 expression alone was not associated with functional impairments, suggesting that TIM-3 expression was a better marker of exhausted CD8+ T cells. The expression of galectin 9, a TIM-3 ligand, in CD4+ Th cells was significantly elevated in malignant, but not benign, Schwannoma patients and were enriched in CD25+ Treg cells. Both the PD-1-TIM-3+ and PD-1+TIM-3+ CD8+ T cells responded to Treg-mediated and galectin 9-mediated suppression, whereas the PD-1+TIM-3- CD8+ T cells only responded to Treg-mediated suppression. In resected tumors, the malignant Schwannomas had more tumor-infiltrating CD4+ and CD8+ T cells than the benign Schwannomas, but a large fraction of these tumor-infiltrating CD4+ and CD8+ T cells expressed PD-1 and/or TIM-3, which indicated that their antitumor immunity was compromised. Together, our results suggested that PD-1 and TIM-3 blockade might be necessary in developing effective immunotherapeutic strategies in malignant Schwannoma, in which TIM-3 may play a more important role.

Benign Glandular Schwannoma With Ancient Change

Benign glandular schwannomas are rare and should be distinguished from malignant peripheral nerve sheath tumors with similar divergent tissue differentiation. The authors present a benign glandular schwannoma with ancient change that developed in the subcutis of a 46-year-old man's posterior calf. He lacked stigmata of neurofibromatosis type 1 (NF1). The glandular elements stained positively for epithelial membrane antigen and pancytokeratin. The spindled cells stained positively for SOX10 and S100 protein, supporting schwannian (neural crest) differentiation. The tumor's location and histopathology suggest that the pathogenesis stems from entrapment of sweat glands. Finally, it must be recognized that ancient change may mimic malignancy in these neoplasms as the malignant counterparts have a greater association with NF1 and a poorer prognosis.

Clinical Features and Surgical Treatment of Schwannoma Affecting the Base of the Tongue: A Systematic Review.

Introduction Schwannomas of the head and neck account for 25–40% of all cases, with presentation at the base of the tongue as the most frequent site for intraoral tumors. Objectives Here, a systematic review was conducted to include 15 cases of patients with schwannoma of the base of the tongue. Data Synthesis Most patients presented with a single, painless, well-encapsulated nodule at the base of the tongue. These nodules were slow-growing, with an average of 13.3 months from onset to presentation. Most cases were accompanied by airway obstruction, indicated by symptoms of dysphagia, dysarthria, snoring, and sleep apnea. Overall, the histological studies were consistent with a benign schwannoma with a palisading Antoni A and Antoni B pattern without malignant changes in cell morphology. These tumors were treated via complete surgical excision, and all cases achieved full remission by final follow-up. Conclusion Surgical removal is the primary mode of treatment with excellent postoperative prognosis and rare instances of recurrence. Given the rarity of this tumor, this review of available case studies serves to comprehensively describe clinical presentation and surgical treatment approaches to tongue base schwannoma.

Benign cardiac schwannoma: A case report

We present an interesting case of a 47-year-old female with an incidental finding of a cardiac tumor located between the right atrium and right ventricle. After some time, the patient became symptomatic, the mass was excised, and pathological studies revealed it to be a benign schwannoma. Schwannomas are tumors of nerve sheaths commonly found in cranial and peripheral nerves. Their occurrence in the heart is exceedingly rare.

A rare case of primary benign schwannoma of the pleura

ABSTRACT Schwannoma, also called neurilemmoma, is a benign peripheral nerve sheath tumor. Most common locations are flexor surfaces of the extremities, neck, mediastinum, retroperitoneum, posterior spinal roots, and cerebellopontine angle. Pleural schwannomas are extremely rare neoplasms of the thoracic cavity. To the best of our knowledge, till date, <20 cases have been reported. Herein, we report a case of primary benign pleural schwannoma in an elderly 60-year-old female in whom the pleural mass was discovered incidentally on computed tomography chest. The patient was subjected to left posterolateral thoracotomy; pleural mass was resected which showed histopathological and immunohistochemical features of schwannoma.

Unusual gastric tumors and tumor-like lesions: Radiological with pathological correlation and literature review.

Although gastric tumors have overlapping radiologic appearances, some unusual tumors may present specific imaging features. Using multidetector computed tomography (MDCT), with water as a negative oral contrast agent and intravenous contrast medium, can provide critical information for the diagnosis of gastric diseases. In addition, MDCT can evaluate the involvement of the gastric wall and extragastric extent of the disease, as compared with gastroenteroscopy and double-contrast upper gastrointestinal study. Regarding lesion location and size, enhancing and growth patterns, presence of calcification or fat, and involvement of the gastric wall and adjacent structures, CT may provide useful information. In this review article, we review the relevant literature and discuss the CT features and the histopathologic findings of different types of gastric lesions. The lesions are divided into benign (glomus tumors, schwannomas, leiomyomas, and lipomas), malignant (gastrointestinal stromal tumors, mucinous carcinomas, lymphomas, and carcinoid tumors), and tumor-like lesions (ectopic pancreas and bezoar). Familiarity with imaging appearances and pathologic findings can help physicians make an accurate diagnosis.

Clinical, Morphologic, and Pathologic Features Associated With Increased FDG Uptake in Schwannoma.

The objective of this study was to investigate the clinical, morphologic, and pathologic features associated with increased 18F-FDG uptake in benign schwannomas. Twenty-two schwannomas in 22 patients (age range, 25-81 years) who had FDG PET or PET/CT scans and subsequently underwent surgical re-section were retrospectively analyzed. The maximum standardized uptake value (SUVmax) was compared with patient age, sex, tumor location (gastrointestinal vs nongastrointestinal origin), tumor size, gross appearance, intratumoral cellularity, intratumoral infiltration of inflammatory cells, presence of peritumoral lymphoid cuffs, and expression status of glucose transporters 1 and 3 on tumor cells. The SUVmax of schwannomas ranged from 1.5 to 17.3 (median, 3.7). Significantly higher SUVmax was observed in gastrointestinal schwannomas (n = 4) compared with nongastrointestinal schwannomas (n = 18, p = 0.007) and in schwannomas with peritumoral lymphoid cuffs (n = 5) compared with those without peritumoral lymphoid cuffs (n = 17, p = 0.001). A significant correlation was seen between tumor location and the presence of peritumoral lymphoid cuffs (p < 0.001). Age, sex, tumor size, gross appearance, intratumoral cellularity, intratumoral inflammatory cell infiltration, and expression status of glucose transporters 1 and 3 on tumor cells had no significant correlation with SUVmax. Gastrointestinal schwannomas and schwannomas with peritumoral lymphoid cuffs may be associated with elevated FDG uptake. Knowledge of the features of schwannomas associated with increased uptake may be helpful to avoid misinterpretation of benign schwannomas as malignancy.

Image characteristics of chest schwannoma in coincidence 18F-FDG SPECT studies

Objective To analyze the image characteristics of chest schwannoma in coincidence 18F-FDG SPECT studies, and to evaluate its prospective diagnostic function on chest schwannoma. Methods Four cases confirmed as schwannoma by surgery and pathology were enrolled in this retrospective study. Enhanced CT and coincidence 18F-FDG SPECT studies were performed before surgery. Imaging characteristics for the diagnosis of chest schwannoma were summarized. Results Tumors were totally removed by surgery. The histological diagnosis of schwannoma was confirmed by pathological, HE and immunohistological staining examination (positivity for the S-100 protein and vimentin), including 1 case of malignant schwannoma and 3 cases of benign. Four cases all showed high uptake of 18F-FDG. The uptake in malignant schwannoma was much higher than that in benign schwannoma. Benign schwannomas were noninvasive masses and mainly showed compression symptoms, with obvious lobulation and distinct borders. Malignant schwannoma was invasive masses. Conclusions 18F-FDG coincidence SPECT is of limited value as a prospective diagnostic imaging technique for the identification of benign schwannoma from malignant schwannoma. But it could play an important role in the staging, restaging, and post-therapy follow-up of schwannoma. Key words: Neurilemmoma; Trachea; Mediastinum; Tomography, emission-computed, single-photon; Coincidence imaging; Deoxyglucose

Nerve sheath tumor, benign neurogenic slow-growing solitary neurilemmoma of the left ulnar nerve: A case and review of literature

AbstractThis paper represent a report of a case with ulnar nerve schwannoma (neurilemmoma), benign neurogenic slow-growing, tumors originating from Schwann cells along the course of a nerve (1) (2) (3). Schwannomas are the most common tumors of the peripheral nerves which occur in the adults (0.8–2%) (5). Usually they progress slowly and so they can remain painless swellings for a few years before other symptoms appear. Most of these lesions could be diagnosed clinically, are mobile in the longitudinal plane along the course of the involved nerve but not in the transverse plane (7). EMG, MRI, and ultrasonography are useful tools in the diagnosis. The definitive treatment of benign peripheral nerve schwannomatosis is complete enucleation of the tumor mass without damaging the intact nerve fascicles followed by confirmatory hystopathological examination (12). We present the case of a 62 years old right hand-dominant female who notice a slow increasing bulge over the inner aspect of her distal volar left forearm superior to the wrist, for a longer period of time not exactly specified; this was tracked and associated by pain, tingling and numbness over inner one and half fingers of her left hand in progress until the presentations. A diagnosis of soft-tissue tumor was presumed clinically. The other investigations were ultrasonography (US), nerve conduction studies (NCSs) such as sensory nerve action potential (SNAP) and compound muscle action potential (CMAP). In this case IRM was suggestive of a benign growth in her left ulnar nerve in the forearm region. Microsurgical techniques were used for ample enucleation of the tumor the distal volar left forearm. Subsequent histopathological examination confirmed the presumed diagnosis of a benign cellular schwannoma. At her last follow-up one month after surgery, the patient was neurological gradually improving sensory and motor function and she is highly satisfied with the results of surgery.

N-methyl-N-nitrosourea-induced schwannomas in male Sprague-Dawley rats with a literature review of inducible and spontaneous lesions

N-methyl-N-nitrosourea (MNU) possesses peripheral nervous system carcinogenic activity in rats and induces benign and malignant schwannomas in systemic organs. In this retrospective study, we compared the characteristics of various immunohistochemical markers in MNU-induced schwannomas in male Crj:CD(SD)IGS rats including: vimentin (Vim), S100, p75 nerve growth factor receptor (LNGFR), CD57, pancytokeratin (CK), myoglobin, desmin and α smooth muscle actin (SMA). Single intraperitoneal exposures of 50 or 75mg/kg MNU in male rats at the age of 4 weeks induced schwannomas in 43 surviving and terminated rats up to 30-weeks-old. The incidence rate of neoplastic lesions was 37% (16 of 43 rats). Benign schwannomas (mesentery, pancreas, thymus) and malignant schwannomas (subendocardium, cardiac intramural, thoracic cavity, abdominal cavity, prostate), occurred in nine and seven rats, respectively. All neoplastic lesions were moderately or strongly positive for Vim, S100 and LNGFR proteins. Benign tumors were weakly positive and malignant tumors strongly positive for Ki-67, suggesting a high active proliferation rate of Schwann cell precursors. All lesions were negative for CD57, CK, myoglobin, desmin and SMA. This data may provide useful immunohistochemical information for the investigation of schwannomas in rat chemical carcinogenicity studies.

Laparoscopic resection of benign schwannoma in the hepatoduodenal ligament: A case report and review of the literature.

Schwannomas are mesenchymal neoplasms with a low malignant potential, which arise from Schwann cells. The tumors can occur in most parts of the body; however, the head, neck and flexor surfaces of the extremities are the most common locations. Schwannomas occurring in the hepatoduodenal ligament are extremely rare. To the best of our knowledge, only two cases of schwannoma in the hepatoduodenal ligament have been reported in the literature, and treatment of such cases by laparoscopic surgery has not yet been reported. The present study reports a case of schwannoma in the hepatoduodenal ligament in a 50-year-old male patient. Physical and laboratory examinations showed no abnormal results. Ultrasound and computed tomography failed to definitively diagnose the mass and identify its location. During laparoscopic surgery, a mass was identified in the hepatoduodenal ligament and was completely removed. The gross specimen was a 4.5×2.5×2.5-cm localized mass, yellowish-white in color. Microscopic examination revealed that the tumor was mainly composed of spindle-shaped cells and no atypical cells were identified. Immunohistochemical staining showed a strong positive S-100 protein reaction, whereas cluster of differentiation 34 and epithelial membrane antigen were negative. The final diagnosis of the lesion was benign schwannoma of the hepatoduodenal ligament. The patient was followed-up for 7 months and, at the time of writing, was healthy and without any complications. The aim of the present study was to describe a rare case of hepatoduodenal ligament schwannoma in a 50-year-old male patient, and present a review of the literature. To the best of our knowledge, this is the first case of hepatoduodenal ligament schwannoma treated by laparoscopic surgery.