Cellular Schwannoma Research Articles

Benign solitary schwannoma of right ulnar nerve – A case report

Introduction: Benign peripheral nerve schwannomas are uncommon tumours. Extra cranial schwannomas have also been reported from uncommon and unusual sites including breast, pancreas, and gastrointestinal system. Peripheral nerve schwannomas may pose a problem in clinical diagnosis, however an appropriate diagnostic work-up including thorough history and clinical examination, Ultrasonography, magnetic resonance imaging, fine needle aspiration cytology, nerve conduction velocity and electromyography study may all help reaching the correct preoperative diagnosis. The important clinical differential diagnoses include traumatic neuroma, neurfibromas, lipoma, cold abscess and muscle hernia. The definitive treatment of benign peripheral nerve schwannoma is complete enucleation of the tumour mass without damaging the intact nerve fascicles followed by confirmatory histopathological examination. When there is a doubt on histopathology, a positive Immunohistochemical staining with S100 is helpful in confirming a diagnosis of schwannoma. Case presentation: We had 40 years female who had a slow growing swelling over the inner aspect of her right elbow for the last one year; this was followed by pain, tingling and numbness over inner one and half fingers of her right hand for six months. Tinnels sign was positive over the swelling. Her subsequent clinical examination and investigations including a magnetic resonance imaging was suggestive of a benign growth in her right ulnar nerve in the elbow region. Complete enucleation of the swelling was done from the right ulnar nerve in the elbow region and subsequent histopathological examination confirmed it to be a benign cellular schwannoma. Patient recovered successfully after the surgery and paresthesia in the distribution of her right ulnar nerve also improved six weeks after surgery. At her last follow-up six months after surgery, the patient was completely asymptomatic and highly satisfied with the results of surgery. Conclusion: A correct preoperative diagnosis of peripheral nerve schwannomas is possible, and it can be successfully managed with complete enucleation of tumour mass with satisfactory patient outcomes.

Intrarenal cellular schwannoma

Schwannomas are tumours arising from the nerve sheath. Renal schwannomas are extremely rare and have non-specific symptoms and limited radiological features. They are often diagnosed histologically after surgical excision. Cellular schwannoma is a rare variant of schwannoma, characterised by almost entirely Antoni A pattern growth and absence of verocay bodies. They may be confused with sarcomatoid renal cell carcinoma, malignant peripheral nerve sheath tumours, angiomyolipoma, leiomyoma and mesoblastic nephroma of the adult type. Recognition and awareness of these rare, benign tumours will assist in the differential diagnosis of spindle cell tumours of the kidney. Predilection for the cellular variant to occur on this site may result in a misdiagnosis of the relatively more commonly occurring sarcomatoid renal cell carcinoma. This is a case of cellular intrarenal schwannoma which was diagnosed by histopathology post-radical nephrectomy. Schwannomas are tumours arising from the nerve sheath. Renal schwannomas are extremely rare and have non-specific symptoms and limited radiological features. They are often diagnosed histologically after surgical excision. Cellular schwannoma is a rare variant of schwannoma, characterised by almost entirely Antoni A pattern growth and absence of verocay bodies. They may be confused with sarcomatoid renal cell carcinoma, malignant peripheral nerve sheath tumours, angiomyolipoma, leiomyoma and mesoblastic nephroma of the adult type. Recognition and awareness of these rare, benign tumours will assist in the differential diagnosis of spindle cell tumours of the kidney. Predilection for the cellular variant to occur on this site may result in a misdiagnosis of the relatively more commonly occurring sarcomatoid renal cell carcinoma. This is a case of cellular intrarenal schwannoma which was diagnosed by histopathology post-radical nephrectomy.

Retroperitoneal cellular schwannoma (CS): a potential pitfall of malignancy. Report of a case and review of the literature

Cellular Schwannoma (CS) is a well-recognized morphological variant of schwannoma, which has been reported in many usual and unusual sites. We herein report a rare case of a bulky, retroperitoneal cellular schwannoma showing

FDG-PETで異常集積像を呈した巨大富細胞性神経鞘腫の1例

FDG-PETで異常集積像を呈した巨大富細胞性神経鞘腫の1例

Cellular schwannoma arising from the gastric wall misdiagnosed as a gastric stromal tumor: A case report

Cellular schwannomas have been previously described at almost every anatomic location of the human body, but reports in the gastric wall are rare. The current study presents a rare case of cellular schwannoma originating from the gastric wall. Computed tomography revealed a 5.6×5.3×4.0-cm3 solid mass located in the posterior wall of the stomach. Open laparotomy confirmed its mesenchymal origin. Microscopically, the tissue was composed of spindle-shaped and fascicularly-arranged cells, but mitotic figures were rare. Immunohistochemical staining showed that the tumor was negative for cluster of differentiation (CD)117, CD34, smooth muscle actin and desmin, but positive for S-100 and Ki67. The patient presented no evidence of recurrence and metastasis during follow-up. Gastric cellular schwannomas may be diagnosed by clinical characteristics, histological observations and immunohistochemical markers.

Conventional spindle cell–type malignant peripheral nerve sheath tumor arising in a sporadic schwannoma

Malignant peripheral nerve sheath tumor is a malignant tumor showing nerve sheath differentiation. Approximately one-half of malignant peripheral nerve sheath tumors arise from a benign peripheral nerve sheath tumor, which is commonly a neurofibroma in patients with neurofibromatosis type 1. Malignant peripheral nerve sheath tumor arising in a sporadic schwannoma of soft tissue is extremely rare. In this condition, malignant cells usually show epithelioid morphology, meeting the diagnostic criteria for epithelioid malignant peripheral nerve sheath tumor. Here, we present an extraordinary case of spindle cell-type malignant peripheral nerve sheath tumor arising in a schwannoma on the back of a 58-year-old woman without neurofibromatosis. The malignant component showed hypercellular spindle cell proliferation with high mitotic activities; in contrast, the benign component showed hypocellular spindle cell proliferation in a palisading pattern and with Verocay bodies. Immunohistochemical S-100 protein staining showed a clear contrast between the malignant (negative) and benign (positive) components, which was useful for differentiating cellular schwannoma. Recognizing this rare condition is helpful in the pathologic diagnosis of schwannoma showing cellular proliferation in part.

Adrenal Schwannoma: A Rare Type of Adrenal Incidentaloma

Adrenal schwannoma is a rare type of adrenal incidentaloma, an adrenal lesion found incidentally, usually on imaging or autopsy. Computed tomography and magnetic resonance imaging are tools used to evaluate adrenal lesions. The diagnosis of adrenal schwannoma, however, cannot be made on imaging alone. Surgical resection is the primary means of management of adrenal schwannomas, as it is not possible to distinguish the schwannoma from malignant entities simply based on imaging. Histopathologic features of adrenal schwannomas are similar to those of schwannomas found at other sites. Conventional schwannomas, consisting of alternating Antoni A and Antoni B areas as well as Verocay bodies, have distinct microscopic features and can be readily distinguished from other entities. Cellular schwannomas, on the other hand, consist only of intersecting fascicles of spindle cells or Antoni A areas, resulting in a wide differential diagnosis. Ancillary studies such as immunohistochemical analysis and electron microscopy can help to provide a specific diagnosis.

Clinical analysis of cellular schwannoma in the gastric wall misdiagnosed as gastric stromal tumor

Cellular schwannoma is a rare benign tumor of the peripheral nerves.The tumor is consist of spindle cells which arranged in interwoven bundles,and lacking the mesh district and palisading structure.The tumor cells are abundant,with coarse chromatin,deeply stained nuclei and in multiforms.So the tumor may easily be misdiagnosed as various types of spindle cell sarcoma.Intraperitoneal cellular schwannoma may also be mistaken as gastrointestinal stromal tumors.In this article,the clinical characteristics,diagnosis and treatment of cellular schwannoma were analyzed based on the clinical data of a patient with cellular schwannoma in the gastric wall misdiagnosed as gastric stromal tumor. Key words: Gastric neoplasms; Schwannoma; Diagnosis

Cellular schwannoma arising from sigmoid mesocolon presenting as torsion

Schwannomas are a type of peripheral nerve sheath tumors with clinically indolent behavior. Though, they can occur anywhere in body, the incidence in retroperitoneum, mediastinum, and pelvis is exceedingly rare. We present a case of a 58-year-old female with a massive twisted tumor arising from sigmoid mesocolon. The tumor was diagnosed to be a case of cellular schwannoma, an exceedingly rare tumor in this location with rare presentation.

Giant Invasive Sacral Schwannoma Showing Chromosomal Numerical Aberrations [-14,+18,+22

Here, we report on a rare case of a giant invasive sacral schwannoma. The patient was a 58-year-old woman who had a 6-year history of non-specific buttock pain. Histological investigation confirmed the diagnosis of cellular schwannoma. The following numerical aberration was detected using the GTG-banding method for karyotypes: 47,XX,-14,+18,+22. Cytogenetic studies of schwannomas have indicated a complete or partial loss of chromosome 22 as the most common abnormality, but this case is cytogenetically rare because of the recurrence of trisomy 22.

NY-ESO-1 expression in synovial sarcoma and other mesenchymal tumors: significance for NY-ESO-1-based targeted therapy and differential diagnosis

AbstractA promising targeted therapy against NY-ESO-1 (CTAG 1B) using genetically modified T-cells in synovial sarcomas was recently demonstrated in a clinical trial at the NCI. To investigate the role of NY-ESO-1 immunohistochemistry in patient selection and gain better insight into the incidence of NY-ESO-1 expression in synovial sarcomas and other mesenchymal tumors, we evaluated NY-ESO-1 expression by immunohistochemistry in 417 tumors. This collection of samples included: 50 SS18/SSX1/2 fusion positive synovial sarcomas, 155 gastrointestinal stromal tumors (GIST), 135 other spindle cell sarcomas as well as 77 other sarcomas (chondrosarcoma, osteosarcoma, dedifferentiated liposarcoma, alveolar soft part sarcoma, rhabdomyosarcoma, angiosarcoma, malignant mesothelioma, and Ewing’s sarcoma). We report that 76% of synovial sarcomas expressed NY-ESO-1 in a strong and diffuse pattern (2−3+, >50–70% of tumor cells). In contrast, only rare cases of other spindle cell mesenchymal tumor expressed NY-ESO-1 (GIST (2/155), malignant peripheral nerve sheath tumors (1/34), and dermatofibrosarcoma protuberans (2/20)). Individual cases of other sarcomas (angiosarcoma, malignant mesothelioma, chondrosarcoma, osteosarcoma, dedifferentiated liposarcoma, alveolar soft part sarcoma, and Ewing’s sarcoma) were positive for NY-ESO-1. However, no positive cases were identified amongst our cohort of leiomyosarcomas (0/24), hemangiopericytoma/solitary fibrous tumors (0/40), and cellular schwannomas (0/17). In summary, we find that NY-ESO-1 is strongly and diffusely expressed in a majority of synovial sarcomas, but only rarely in other mesenchymal lesions. Beyond its role in patient selection for targeted therapy, immunohistochemistry for NY-ESO-1 may be diagnostically useful for the distinction of synovial sarcoma from other spindle cell neoplasms.

Pathology of peripheral nerve sheath tumors: diagnostic overview and update on selected diagnostic problems

Peripheral nerve sheath tumors are common neoplasms, with classic identifiable features, but on occasion, they are diagnostically challenging. Although well-defined subtypes of peripheral nerve sheath tumors were described early in the history of surgical pathology, controversies regarding the classification and grading of these tumors persist. Advances in molecular biology have provided new insights into the nature of the various peripheral nerve sheath tumors, and have begun to suggest novel targeted therapeutic approaches. In this review, we discuss current concepts and problematic areas in the pathology of peripheral nerve sheath tumors. Diagnostic criteria and differential diagnosis for the major categories of nerve sheath tumors are proposed, including neurofibroma, schwannoma, and perineurioma. Diagnostically challenging variants, including plexiform, cellular and melanotic schwannomas are highlighted. A subset of these affects the childhood population, and has historically been interpreted as malignant, although current evidence and outcome data suggest they represent benign entities. The growing current literature and the author's experience with difficult to classify borderline or "hybrid tumors" are discussed and illustrated. Some of these classification gray zones occur with frequency in the gastrointestinal tract, an anatomical compartment that must always be entertained when examining these neoplasms. Other growing recent areas of interest include the heterogeneous group of pseudoneoplastic lesions involving peripheral nerve composed of mature adipose tissue and/or skeletal muscle, such as the enigmatic neuromuscular choristoma. Malignant peripheral nerve sheath tumors (MPNST) represent a diagnostically controversial group; difficulties in grading and guidelines to separate "atypical neurofibroma" from MPNST are provided. There is an increasing literature of MPNST mimics which neuropathologists must be aware of, including synovial sarcoma and ossifying fibromyxoid tumor. Finally, we discuss entities that are lacking from the section on cranial and paraspinal nerves in the current WHO classification, and that may warrant inclusion in future classifications. In summary, although the diagnosis and classification of most conventional peripheral nerve sheath tumors are relatively straightforward for the experienced observer, yet borderline and difficult-to-classify neoplasms continue to be problematic. In the current review, we attempt to provide some useful guidelines for the surgical neuropathologist to help navigate these persistent, challenging problems.

A spinal epidural dumbbell cellular schwannoma in an infant

Intraspinal schwannoma is a rare neoplasm in pediatric patients; cellular schwannoma is an unusual histological subtype of schwannoma. A six-month-old infant with an epidural dumbbell cellular schwannoma presented with progressive weakness of his arms and legs. A spinal MRI revealed an epidural mass from C5 to T4, and a complete surgical resection was achieved after laminotomy and facetectomy. The patient experienced a gradual neurological improvement and was still healthy without recurrence at the latest follow-up. The diagnosis of cellular schwannoma was confirmed on immunohistological examination.

Clinicopathologic and Molecular Analysis of a Choroidal Pigmented Schwannoma in the Context of a PTEN Hamartoma Tumor Syndrome

To report the first case of choroidal schwannoma in a patient affected by PTEN hamartoma tumor syndrome (PHTS) and investigate the molecular involvement of the phosphatase and tensin homolog (PTEN) and neurofibromin 2 (NF2) genes in this rare intraocular tumor. Observational case report. A 10-year-old girl diagnosed with PHTS. The enucleated specimen underwent histologic, immunohistochemical, and transmission electronic microscopy. The expression of PTEN and NF2 and their protein products were evaluated by reverse transcription-polymerase chain reaction and immunohistochemistry. Somatic mutations of PTEN and NF2, as well as allelic loss, were investigated by direct sequencing of DNA extracted from the tumor. PTEN epigenetic silencing was investigated by pyrosequencing. Histopathologic and molecular characterization of a choroidal pigmented schwannoma. Histopathologic, immunohistochemical, and electron microscopic analysis demonstrated features consistent with a pigmented cellular schwannoma of the choroid. We found no loss of heterozygosity at the genomic level for the PTEN germline mutation and no promoter hypermethylation or other somatic intragenic mutations. However, we observed an approximate 40% reduction of PTEN expression at both the mRNA and the protein level, indicating that the tumor was nonetheless functionally deficient for PTEN. Although DNA sequencing of NF2 failed to identify any pathologic variants, its expression was abolished within the tumor. We report the first description of a pigmented choroidal schwannoma in the context of a PHTS. This rare tumor showed a unique combination of reduction of PTEN and absence of NF2 expression.

Multiple plexiform schwannoma of a finger

ejd.2011.1609 Auteur(s) : Jiong Zhou, Xiao-Yong Man, Min Zheng, Sui-Qing Cai cai.suiqing@gmail.com Department of Dermatology, Second Affiliated Hospital, Hangzhou 310009, China Schwannomas are benign neurogenic tumors, first described by Verocay in 1908 [1]. There are 7 subtypes: classical (Verocay), cranial nerve, cellular, plexiform, degenerated (ancient), melanotic, and granular cell schwannoma [2]. Plexiform schwannoma is a rare subtype, accounting for approximately 5% of schwannomas [2]. Sometimes, [...]

Clinical analysis of 128 cases of adrenal incidentalomas

Objective To improve the early diagnosis and differential diagnosis of adrenal incidentalomas to guide clinical management of this disease. Methods One hundred and twenty-eight cases were diagnosed as adrenal incidentalomas due to health examination or treatment of other than adrenal disease,including 60 males and 68 females,whose ages were between 20 and 75 years,with a mean age of 50 years.Tumor diamer:＜3 cm 63 cases,3-6 cm 6 cases,＞6 cm 10 cases.128 patients all had biochemical and electrolyte examination,adrenal cortex and medulla biochemical testing,abdominal ultrasound and CT examination,6 cases with MRI examination.Surgery and post operative pathological examination were performed in all patients. Results Post operative pathology finally diagnosed adrenocortical adenoma in 85 cases,pheochromocytoma in 13 cases,adrenal cyst in 8 cases,paraganglioma and myeiolipoma in 7 eases respectively,adrenal nodular hyperplasia in 4 cases,adrenocortical carcinoma in 2 cases,adrenoconical oncocytoma,cellular Schwannoma and adrenal liposarcoma in 1 case,respectively.One case of pheochromocytoma patients died of intraoperative hypotension,which is not included in the total number. Conclusions The preperative diagnosis of adrenal incidentalomas is difficult.For adrenal incidentalomas with diameter more than 6 cm and those with endocrine function,early surgicM treatment is recommended. Key words: Adrenal neoplasms; Incidentaloma; Pheochromocytorna; Cushing syndrome; Laparoscopies

Giant infantile plexiform cellular schwannoma of the knee

We describe an infant with a painless but rapidly enlarging plexiform cellular schwannoma over the anterior aspect of the knee. It is a diagnostic challenge for the histopathologist to differentiate between plexiform schwannoma and a malignant peripheral nerve sheath tumour or plexiform neurofibroma which has an association with neurofibromatosis type 1 and carries a risk of sarcomatous change. This benign peripheral nerve sheath tumour is characterised by a multinodular and plexiform growth pattern. To date no report has been published in the European literature describing a rapidly growing giant plexiform cellular schwannoma in an infant. This diagnostic dilemma and rarity of this condition are the unique features of this case report.

Low-back pain as the presenting sign in a patient with a giant, sacral cellular schwannoma: 10-year follow-up

Giant sacral tumors present unique challenges to surgeons because there is no established consensus regarding the best treatment options. The authors report on the care of and outcome in a patient presenting with low-back pain only, who underwent preoperative biopsy sampling and subsequent embolization of the feeding vessels of a giant, sacral cellular schwannoma. The main procedure was performed via a combined posterior-anterior approach with complete microsurgical removal of the tumor, without the use of instrumentation, bracing, or adjuvant radio- and chemotherapy. At the 10-year follow-up, no evidence of residual tumor, recurrence, or instability was recognizable. Giant, sacral cellular schwannomas can be aggressively completely removed without any significant morbidity, achieving long-term control of the disease.

Trisomy 17 in congenital plexiform (multinodular) cellular schwannoma

Plexiform (multinodular) cellular schwannomas are rare tumors, not associated with neurofibromatosis type 1, that occur more often in children and can be congenital. Their biology is benign and is characterized by the tendency to recur locally without being metastatic. Cytogenetic studies in adult cases of schwannoma indicate a complete or partial loss of chromosome 22 as the most common abnormality. Only two cytogenetic studies describe cases in children, one of which concerned a congenital cellular plexiform schwannoma. Here, we report the cytogenetic analysis of a second case in an 8-month-old boy with recurrence of trisomy 17.

Intrapulmonary Cellular Schwannoma

A 75-year-old asymptomatic woman was admitted to our hospital after an abnormal shadow was found on a chest roentgenogram. Chest computed tomography showed a round mass in the right lower lobe. Magnetic resonance imaging showed the mass with high signal intensity on T2-weighted images and intermediate signal intensity on T1-weighted images. Fluorine-18-fluorodeoxyglucose-positron emission tomography showed high fluorine-18-fluorodeoxyglucose accumulation in the mass. A lobectomy was performed thoracoscopically. The pathologic diagnosis was cellular schwannoma. Immunohistochemical staining demonstrated the presence of S-100 protein, and the Ki67 labeling index was 12%. We present this case of intrapulmonary cellular schwannoma, which is extremely rare.