Rapidly Growing Leiomyoma Mimicking Schwannoma of the Saphenous Nerve in the Lower Extremity: An Unusual Case Report.

Leiomyomas and schwannomas are both types of rare benign soft tissue tumours. Leiomyomas are more commonly found in the lower limbs than in the upper extremities, while schwannomas are rare peripheral nerve sheath tumours that can occur in different anatomical regions. However, they rarely occur in the saphenous nerve. This case study presents a 41-year-old female patient with a solitary mass lesion located deep in the soft tissue of the anteromedial lower extremity. The physical examination revealed a palpable, elastic-hard, mobile and non-tender mass. Magnetic resonance imaging (MRI) showed an oval-shaped subcutaneous mass on contrast-enhanced T1-weighted sections. The initial MRI images suggested a schwannoma, but the tumour was later confirmed to be a leiomyoma after total enucleation. An immunohistochemical study was performed for differential diagnosis. Solitary mass lesions in the lower extremities can be mistaken for various types of tumours and misdiagnosed and require histopathological examination and good radiological imaging for differential diagnosis. Complete surgical excision is usually a safe and effective treatment for leiomyomas.

Resection of a giant intraspinal and extraspinal schwannoma with cystic change using a two-step surgery: a case report.

BACKGROUND: Schwannomas originating from the intravertebral canal rarely extend into the paravertebral region or form large masses. There are few reports on such medical cases, and their clinical diagnosis and management are poorly understood. Here, we report a case of an intraspinal schwannoma with a giant extraspinal mass in a middle-aged Chinese woman and the clinical implications of the symptoms, diagnosis, and treatment of thoracic vertebral schwannoma. CASE PRESENTATION: A 59-year-old female patient who presented with sudden lower limb numbness and difficulty in walking was referred to our department. Magnetic resonance imaging (MRI) revealed a tumor compressing the T11-T12 spinal canal and extensively invading the left thoracic cavity to form a giant paravertebral mass. Schwannoma was diagnosed after intraoperative pathological examination, in which tumor cells were immunoreactive to S100 and Sox10 but negative for smooth muscle actin (SMH). Intraspinal mass resection through the posterior approach and extraspinal chest mass resection under video-assisted thoracoscopy through the left lateral approach were performed simultaneously, and instrumentation was used to maintain thoracic spinal stability. CONCLUSION: In patients with large schwannomas, customized treatment plans are crucial. Tailoring the approach to an individual's specific condition by considering factors such as tumor size and location is essential for optimal outcomes.

[Schwannoma of Intercostal Nerve Resulting in Significant Pain Relief Following Excision:Report of a Case].

An 80-year-old male underwent chest computed tomography (CT) due to complaints of right-sided chest pain. A chest wall tumor was identified in the right eighth intercostal space, corresponding to the location of his pain. The patient was subsequently referred to our department for further evaluation and treatment. Utilizing single-port thoracoscopic surgery, the tumor was successfully excised. Intraoperatively, the tumor was found beneath the parietal pleura, was contiguous with to the intercostal nerve. Histopathological analysis confirmed the diagnosis of schwannoma originating from the intercostal nerve. The right-sided chest pain was reduced after operation significantly. No recurrence or relapse of symptoms was observed during follow-up. Although schwannoma of the chest wall in asymptomatic in many cases, in this case, localized pain corresponding to the tumor site was evident. This emphasizes the importance of considering schwannoma in the differential diagnosis of chest pain.

Narrow-band imaging to enhance intraneural dissection in head and neck schwannoma surgery: a quantitative evaluation.

OBJECTIVE: The objective of this study was to assess the utility of narrow-band imaging (NBI) for improving intraneural dissection during gross total resection of head and neck schwannoma. Specifically, we aimed to quantitatively evaluate whether NBI can enhance the identification of pseudocapsule and true capsule within the tumor. METHODS: Nine schwannoma surgery cases conducted between February 2018 and October 2022 were retrospectively analyzed. The surgical procedures followed established principles with a specific focus on utilizing NBI to distinguish between the pseudocapsule and true capsule. Intraneural dissection was performed by searching for a tumor surface with a fascicle-free window, followed by longitudinal incision of the pseudocapsule. NBI was used to distinguish between the pseudocapsule and true capsule. Surgical views were captured under both white light (WL) illumination and NBI for further analysis. The brightness and contrast of the pseudocapsule and true capsule were quantitatively measured using ImageJ and were compared. RESULTS: Under NBI, the pseudocapsule consistently appeared greenish-gray, whereas the true capsule exhibited a white appearance. Quantitative analysis revealed a statistically significant difference (p < 0.0001) in brightness between the pseudocapsule (mean grayscale value 52.1, 95%CI; 46.4-75.3) and true tumor capsule (mean grayscale value 120.8, 95%CI; 155.7-109.0) under NBI. Conversely, there was no statistically significant difference in the brightness of these structures under WL (p = 0.2067). NBI also showed significantly higher contrast between the two structures than did WL (contrast 73.6, 95%CI; 53.1-89.5 vs. 30.9, 95%CI; 1.0-47.5, p = 0.0034). Further spectral analysis revealed that the most substantial difference in brightness between the pseudocapsule and the true tumor capsule was observed in the red spectrum, with a difference in brightness of -0.6 (95%CI; -16.8-14.8) under WL and 83.5 (95%CI; 50.3-100.0) under NBI (p < 0.0001). CONCLUSION: NBI proved to be a valuable tool for enhancing the identification of pseudocapsule and true capsule during intraneural dissection in head and neck schwannoma surgery. The improved contrast and membrane visibility offered by NBI might have the potential to reduce postoperative neurological deficits and improve surgical outcomes. Further research is warranted to validate our findings and explore the broader applications of NBI in schwannoma surgery.

A Rare Case of a Gigantic Retroperitoneal Schwannoma.

Introduction: Schwannomas (Schs) are benign tumor masses that rarely occur intra-abdominally and rarely reach larger diameters. When present, they occur as rare solitary nerve sheath tumors of peri-neural Schwann cells. Schwannoma mostly affects the nerves of the extremities, trunk, or the head and neck region. They are more common in female patients, mostly among patients between the third and fifth decade. They occur spontaneously but could also be found in association with a group of genetic autosomal dominant disorders called type 2. When present intra-abdominally, schwannomas grow slowly without significant clinical signs and symptoms. Clinical importance is presented in cases of occupying intra-abdominal space and impingement of surrounding structures, which causes intermittent pain. Only 0.5-5% of all retroperitoneal tumors are schwannomas and their malignant transformation is very rare. Case report: The authors present a case of a large intra-abdominal schwannoma in a 70-year-old female patient. She underwent CT scanning due to refractory left-sided subcostal pain, which revealed a large tumor mass in the left-sided hemiabdomen. Preoperative cytologic biopsy confirmed Sch. The patient underwent an MRI scan upon admission to our department, which revealed the origin of the tumor at the left-sided L3 level and intra-abdominal tumor spreading with the largest diameter of 25 cm. The patient underwent multidisciplinary surgical excision, confirmed by MRI scan in a period of five months postoperatively. Conclusions: Its rare presentation leads to the necessity to adequately evaluate such patients, especially to avoid any hidden diagnosis which might lead to further complications. The goal of a multidisciplinary approach should be emphasized as maintaining a good postsurgical condition without neurological deficits.

Thoracoscopic resection of a giant esophageal schwannoma: A case report and review of literature.

INTRODUCTION: Benign esophageal tumors are uncommon, accounting for approximately 2% of esophageal tumors. Esophageal schwannoma is a much rarer solid tumor with few cases reported in the literature. Open surgery is the surgical approach of choice for the treatment of esophageal tumors. With the advent of thoracoscopy, more and more countries are adopting a thoracoscopic approach to treat esophageal tumors, but there is still no clear surgical standard or modality for the treatment of esophageal tumors. PATIENT CONCERNS: A 50-year-old woman was admitted to our hospital. Over the past 2 months, her clinical presentation has included progressively worse swallowing disorder and weight loss. Gastroscopy showed an elevated lesion with a smooth surface visible 18 cm out from the incisors. An electron circumferential ultrasound endoscopy showed a hemispherical bulge with a smooth surface 18 to 23 cm from the incisor; the bulge originated from the intrinsic muscular layer and showed a heterogeneous mixed moderate ultrasound with a little blood flow signal and blue-green elastography in 1 of the sections measuring approximately 4 cm × 3 cm. Chest computed tomography (CT) showed a mass-like soft tissue shadow in the upper esophagus measuring approximately 39 mm × 34 mm, with a CT The lumen was compressed and narrowed, and the lumen of the upper part of the lesion was dilated, and the adjacent trachea was compressed and displaced to the right. INTERVENTIONS: After completion of the examination, assisted by artificial pneumothorax and thoracoscopic resection of esophageal masses were performed. DIAGNOSIS AND OUTCOMES: Postoperative pathology report: Mesenchymal-derived tumor (esophagus), combined with immunohistochemical staining results and morphologic features supported schwannoma. The patient's postoperative course was calm. The patient's postoperative dysphagia subsided. CONCLUSION: We describe a case of successful treatment of a schwannoma of the upper esophagus using artificial pneumothorax-assisted VATS. The combined use of Sox10 and S100 helps to improve the sensitivity and specificity of schwannoma diagnosis. Damage to the esophageal lining was avoided by mixed thoracoscopic and endoscopic exploration. This approach can also be applied to benign esophageal tumors in the thoracic and subthoracic segments, leading to better minimally invasive results.

Intralabyrinthine Schwannoma Mimicking Posterior Canalithiasis.

Intralabyrinthine schwannomas are a rare subgroup of vestibular schwannomas located within the membranous labyrinth of the inner ear and are known for their variable clinical presentations and symptoms. In the present study, we report on a patient with a persistent history of dizziness and positional vertigo, who was misdiagnosed with posterior canalithiasis. As hearing loss was not developed until late in the disease course, the patient was not properly diagnosed until magnetic resonance imaging revealed an intralabyrinthine schwannoma, which was not discovered on earlier imaging. In addition to the unusual clinical presentation, we describe the audio-vestibular profile of our patient. We suggest that a thorough vestibular evaluation, including caloric testing and a careful examination of the inner ear on imaging, is warranted in cases of treatment of refractory vertigo, even in patients where a diagnosis seems certain.

Stereotactic radio-neurosurgery for jugular foramen schwannomas.

BACKGROUND: Stereotactic radiosurgery (SRS) represents a minimally invasive and valuable alternative for jugular foramen schwannomas (JFS), both as upfront and/or adjuvant treatment (in hybrid approaches). METHODS: We conducted a retrospective review of our cases treated at the Lausanne University Hospital (CHUV) from June 2010 to October 2023. Eleven patients underwent SRS, among whom three had prior surgery, two in our center in the frame of a planned combined approach and one in another center. Two patients received "volume-staged" SRS. The mean age at SRS was 60 years (median 68; range 29-83). Cranial nerve (CN) symptoms were present in six patients, while five were asymptomatic. The mean tumor volume at SRS was 2.1 cc (median 1.2; range 0.068-7.3 cc), with a 12 Gy marginal dose prescribed in all cases. RESULTS: The mean follow-up period was 3.9 years (median 2, range 1-7). Cranial nerve function improved after SRS in six patients, while five remained stable. At the last follow-up, all tumors showed a decrease in volume, except for one patient, who underwent surgery at 18 months after SRS, for volumetric increase at 6 and 12 months, with further XII-th CN palsy and medulla oblongata compression. Although tumor decreased at 18 months, such patient needed microsurgical resection for symptom persistence and was further controlled. The mean tumor volume at 1 year post-SRS was 1.6 cc (median 0.55; range 0.028-7.77 cc), at 2 years was 1.31 cc (median 0.76; range 0.19-5), and at 3 years was 1.32 cc (median 0.59; range 0.23-4.8). No adverse radiation events were observed. CONCLUSIONS: Stereotactic radiosurgery is considered a safe and effective treatment for jugular foramen schwannomas, ensuring high rates of tumor control in all patients over the long term. The cranial nerve function improved after SRS in the 6 patients who had deficits and the other 5 patients who had no deficits remained asymptomatic. For larger tumors, combined/hybrid approaches can be a valuable alternative, to obtain tumor control and to preserve neurological function.

Laparoscopic removal of retroperitoneal schwannoma in renal hilum: a case report.

BACKGROUND: Schwannomas in the renal hilum are rare among retroperitoneal tumors. However, the possibility of malignant findings cannot be ruled out, and surgery is often indicated. This case was expected to be difficult to remove laparoscopically because the tumor was sandwiched between the arteriovenous veins of the renal portal. Sometimes, the tumor should be resected with a conservative approach to the kidney to preserve the renal function. CASE PRESENTATION: Our patient was a 51-year-old Asian-Japanese man who was referred to our department for a retroperitoneal tumor in the renal hilum. Since malignancy could not be ruled out due to its size (45 × 48 × 55 mm) on imaging, the tumor was excised laparoscopically. Histopathology revealed schwannoma. CONCLUSIONS: We herein report a case in which a renal hilar tumor between renal arteriovenous vessels was successfully resected laparoscopically.

Application of Computer-Assisted Endoscopic Ultrasonography Based on Texture Features in Differentiating Gastrointestinal Stromal Tumors from Benign Gastric Mesenchymal Tumors.

BACKGROUND/AIMS:  Gastrointestinal stromal tumors are common gastric mesenchymal tumors that are potentially malignant. However, endoscopic ultrasonography is poor in diagnosing gastrointestinal stromal tumors. The study investigated the efficacy of texture features extracted from endoscopic ultrasonography images to differentiate gastrointestinal stromal tumors from gastric mesenchymal tumors. MATERIALS AND METHODS:  The endoscopic ultrasonography examinations of 120 patients with confirmed gastric gastrointestinal stromal tumors, leiomyoma, or schwannoma were evaluated. Histology was considered the gold standard. Three feature combinations were extracted from endoscopic ultrasonography images of each lesion: 48 gray-level co-occurrence matrix-based features, 48 gray-level co-occurrence matrix-based features plus 3 global gray features, and 15 gray-gradient co-occurrence matrix-based features. Support vector machine classifiers were constructed by using feature combinations to diagnose gastric gastrointestinal stromal tumors. The area under the receiver operating characteristic curve, accuracy, sensitivity, and specificity were used to evaluate the diagnostic performance. The support vector machine model's diagnostic performance was compared with the endoscopists. RESULTS:  The 3 feature combinations had better performance in differentiating gastrointestinal stromal tumors: gray-gradient cooccurrence matrix-based features yielded an area under the receiver operating characteristic curve of 0.90, which was significantly greater than an area under the receiver operating characteristic curve of 0.83 in gray-level co-occurrence matrix-based features and an area under the receiver operating characteristic curve of 0.84 in the texture features plus 3 global features. The support vector machine model (81.67% accuracy, 81.36% sensitivity, and 81.97% specificity) was also better than endoscopists (an average of 69.31% accuracy, 65.54% sensitivity, and 72.95% specificity) Conclusion: Texture features in computer-assisted endoscopic ultrasonography diagnosis are useful to differentiate gastrointestinal stromal tumors from benign gastric mesenchymal tumors and compare favorably with endoscopists. Support vector machine model using gray-gradient co-occurrence matrix-based texture features revealed the best diagnostic performance in diagnosing gastric gastrointestinal stromal tumors.

Clinical, Anatomical, and Histological Features of the Rhomboid Lip and Considerations for Surgery Using a Retrosigmoid Approach: A Retrospective Study.

OBJECTIVE: The rhomboid lip is a neural tissue encountered during cerebellopontine angle surgery, with differing shape and extent among individuals. This study aimed to investigate the variation of rhomboid lips during posterior fossa surgery. METHODS: In this retrospective study, we examined posterior cranial fossa surgeries performed using a retrosigmoid approach. Rhomboid lips were classified according to thickness, extent, and appearance, with some subjected to histological analysis. T2-weighted magnetic resonance imaging of rhomboid lips was conducted. RESULTS: Among 304 surgeries, rhomboid lips were observed in 75 patients who underwent schwannoma or meningioma resection, facial spasm-related neurovascular decompression, and other surgeries (37, 2, 32, and 4 patients, respectively). Rhomboid lips were categorized based on apparent thickness: thin membranous type, resembling an arachnoid membrane, and thick parenchymal type. Rhomboid lip extension was classified by position relative to the choroid plexus: nonextension, lateral extension, and jugular foramen (41, 22, and 12 patients, respectively). Veins were observed on the rhomboid lip surface in 37 cases. The rhomboid lip was visible in only 1 case (parenchymal jugular foramen type) on magnetic resonance imaging. Histologically, the rhomboid lip comprised an ependymal cell layer, a glial layer, and connecting tissue. The glial layer thickness determined the rhomboid lip thickness, which was greater in the parenchymal type than in the membrane type. In 42 patients, the rhomboid lip was dissected with no complications observed. CONCLUSIONS: Morphological classification of the rhomboid lip and understanding of its anatomical details contribute to safe surgical field development for neurosurgeons.

Management of a giant adrenal schwannoma.

In this case report, we present a man in his 60s who presented with an incidentally discovered right adrenal mass, which turned out to be an adrenal schwannoma. This is a very rare tumour that originates from Schwann cells and involves the peripheral nerves. The tumour was removed by open adrenalectomy, and this 15-cm adrenal schwannoma is one of the largest reported in the literature, with none >16 cm having ever been reported. This case highlights the importance of keeping an open mind about the cause of an incidentally discovered adrenal mass, which is an increasingly common way for adrenal tumours to present given the increased access to cross-sectional imaging. As well as presenting the case and the pathological basis behind adrenal schwannomas, we include a review of the literature and a general discussion about incidentally discovered adrenal masses.

Image features and clinical analysis of retroperitoneal pelvic schwannoma: a case report.

BACKGROUND: Schwannomas are benign usually encapsulated nerve sheath tumors derived from the Schwann cells, and affecting single or multiple nerves. The tumors commonly arise from the cranial nerves as acoustic neurinomas but they are extremely rare in the pelvis and the retroperitoneal area. Retroperitoneal pelvic schwannomas often present with non-specific symptoms leading to misdiagnosis and prolonged morbidity. CASE PRESENTATION: We report the case of a 59-year-old woman presenting with a feeling of heaviness in the lower abdomen who was found to have a retroperitoneal pelvic schwannoma originating from the right femoral nerve. She had a history of two resections of peripheral schwannomas at four different sites of limbs. After conducting magnetic resonance imaging, this pelvic schwannoma was misdiagnosed as a gynecological malignancy. The tumor was successfully removed by laparoscopic surgery. Pathological analysis of the mass revealed a benign schwannoma of the femoral nerve sheath with demonstrating strong, diffuse positivity for S-100 protein. CONCLUSIONS: Although retroperitoneal pelvic schwannoma is rare, it should be considered in the differential diagnosis of pelvic masses, especially in patients with a history of neurogenic mass or the presence of neurogenic mass elsewhere.

18 F-FDG PET/CT of Benign Tracheal Schwannoma.

ABSTRACT: Schwannoma is a benign tumor originating from Schwann cells. It commonly occurs in the head, neck, and extremities, but rarely occurs in the trachea. Tracheal schwannoma is usually asymptomatic. We reported the 18 F-FDG PET/CT findings of a 61-year-old man with bronchoscopically biopsy-proven schwannoma, which presented challenges in differentiation from certain benign tumors and low-grade malignancies in the trachea.

Laryngeal schwannoma masquerading as malignancy.

Laryngeal schwannoma is a rare type of neurogenous tumour with a non-specific presentation. We present a case of a middle-aged man with issues of hoarseness, globus sensation and intermittent episodes of throat pain. The Hopkins examination showed right vocal fold irregularity with fullness in the right ventricle. The contrast-enhanced CT neck revealed an ill-defined lesion with contrast uptake extending into the paraglottic region with no neck node involvement. Considering the clinical presentation of hoarseness, throat pain and globus with imaging revealing contrast enhancement of lesion, direct laryngoscopy and biopsy were planned to rule out malignancy. Intraoperatively, a well-defined submucosal capsulated swelling became apparent after incision and dissection of the mucosa over the right vocal fold. A complete excision of the swelling was done with microlaryngeal instruments without tracheostomy. The histopathological report was suggestive of schwannoma. The literature review discusses clinical presentation, location, imaging features and management strategy.

The utility of intraoperative ultrasonography for spinal cord surgery.

OBJECTIVES: Intraoperative ultrasonography (IOUS) offers the advantage of providing real-time imaging features, yet it is not generally used. This study aims to discuss the benefits of utilizing IOUS in spinal cord surgery and review related literature. MATERIALS AND METHODS: Patients who underwent spinal cord surgery utilizing IOUS at a single institution were retrospectively collected and analyzed to evaluate the benefits derived from the use of IOUS. RESULTS: A total of 43 consecutive patients were analyzed. Schwannoma was the most common tumor (35%), followed by cavernous angioma (23%) and ependymoma (16%). IOUS confirmed tumor extent and location before dura opening in 42 patients (97.7%). It was particularly helpful for myelotomy in deep-seated intramedullary lesions to minimize neural injury in 13 patients (31.0% of 42 patients). IOUS also detected residual or hidden lesions in 3 patients (7.0%) and verified the absence of hematoma post-tumor removal in 23 patients (53.5%). In 3 patients (7.0%), confirming no intradural lesions after removing extradural tumors avoided additional dural incisions. IOUS identified surrounding blood vessels and detected dural defects in one patient (2.3%) respectively. CONCLUSIONS: The IOUS can be a valuable tool for spinal cord surgery in identifying the exact location of the pathologic lesions, confirming the completeness of surgery, and minimizing the risk of neural and vascular injury in a real-time fashion.