Schwannoma Presenting as a Scalp Mass: A Case Report with Magnetic Resonance Imaging Findings

Schwannoma of the Tongue Base with Imaging Features and Differential Diagnosis: a Rare Case Report and Literature Review

Schwannoma or neurilemmoma is a benign peripheral nerve sheath tumor that arises from Schwann cells. Approximately 25–45% of all schwannomas occur in the head and neck regions, and the intraoral presentation of these is only 1%. We report a rare case of a patient presenting tongue base schwannoma with characteristic imaging features on computed tomography and magnetic resonance imaging.

Analysis According to Characteristics of 18 Cases of Brachial Plexus Tumors : A Review of Surgical Treatment Experience

OBJECTIVE: Because the anatomical structure of the brachial plexus is very complex, surgical treatment of tumors in this region is challenging. Therefore, a lot of clinical and surgical experience is required for successful treatment; however, many neurosurgeons have difficulty accumulating this experience owing to the rarity of brachial plexus tumors. The purpose of this report is to share our surgical experience with brachial plexus tumor with other neurosurgeons.METHODS: The records of 18 consecutive patients with brachial plexus tumors who underwent surgical treatment between January 2010 and December 2017 in a single institution were retrospectively reviewed. The surgical approach was determined according to the tumor location and size, and intraoperative neurophysiological monitoring (IONM) was used in most of cases to prevent iatrogenic nerve injury during surgery. In addition, to evaluate the differences in tumor characteristics according to pathologic diagnosis, the tumors were divided twice into two groups, based on two separate classifications, and statistical analysis was performed.RESULTS: The 18 brachial plexus tumors comprised 15 (83.3%) benign peripheral nerve sheath tumors including schwannoma and neurofibroma, one (5.6%) malignant peripheral nerve sheath tumor, one (5.6%) benign tumor of non-neural sheath origin (neurogenic cyst), and one (5.6%) metastatic tumor (papillary carcinoma). The authors analyzed relationship between tumor size/location and tumor characteristic parameters such as age, size, right-left, and pathology. There were no statistically significant differences except a tendency of bigger tumor size in young age.CONCLUSION: For a successful surgical outcome, an appropriate surgical approach is essential, and the appropriate surgical approach is determined by the location and size of the tumor. Furthermore, applying IONM may prevent postoperative complications and it is favorable option for brachial plexus tumors surgery.

Analysis According to Characteristics of 18 Cases of Brachial Plexus Tumors : A Review of Surgical Treatment Experience

OBJECTIVE: Because the anatomical structure of the brachial plexus is very complex, surgical treatment of tumors in this region is challenging. Therefore, a lot of clinical and surgical experience is required for successful treatment; however, many neurosurgeons have difficulty accumulating this experience owing to the rarity of brachial plexus tumors. The purpose of this report is to share our surgical experience with brachial plexus tumor with other neurosurgeons. METHODS: The records of 18 consecutive patients with brachial plexus tumors who underwent surgical treatment between January 2010 and December 2017 in a single institution were retrospectively reviewed. The surgical approach was determined according to the tumor location and size, and intraoperative neurophysiological monitoring (IONM) was used in most of cases to prevent iatrogenic nerve injury during surgery. In addition, to evaluate the differences in tumor characteristics according to pathologic diagnosis, the tumors were divided twice into two groups, based on two separate classifications, and statistical analysis was performed. RESULTS: The 18 brachial plexus tumors comprised 15 (83.3%) benign peripheral nerve sheath tumors including schwannoma and neurofibroma, one (5.6%) malignant peripheral nerve sheath tumor, one (5.6%) benign tumor of non-neural sheath origin (neurogenic cyst), and one (5.6%) metastatic tumor (papillary carcinoma). The authors analyzed relationship between tumor size/location and tumor characteristic parameters such as age, size, right-left, and pathology. There were no statistically significant differences except a tendency of bigger tumor size in young age. CONCLUSION: For a successful surgical outcome, an appropriate surgical approach is essential, and the appropriate surgical approach is determined by the location and size of the tumor. Furthermore, applying IONM may prevent postoperative complications and it is favorable option for brachial plexus tumors surgery.

Schwannoma of the Common Peroneal Nerve – A Rare Incidence

Schwannomas are benign tumours arising from neurilemmal cells which forms the myelin sheath of peripheral nerves. It usually occurs in the head, but may be found in the brachial plexus and sciatic nerve. Common peroneal nerve schwannoma are rare. We report a case of a middle age gentleman who presented with pain and swelling over the right popliteal fossa with associated right radicular pain of the anterolateral leg and weakness of ankle dorsiflexion. Examination revealed a 3x2 cm lump behind the posterolateral aspect of the right knee with positiveTinel’s sign upon tapping of the lump, sensory deficit over the anterolateral aspect of the leg and the ankle dorsiflexors had a muscle power of grade 3. Magnetic resonance imaging (MRI) of the right leg revealed a well circumscribed, oval lesion located along the pathway of the common peroneal nerve homogenously hypointense on T1-weighted images and heterogeneously hyperintense on T2 weighted images compared to the muscles. The lesion was not surpressed on fat suppression sequences. Intra-operatively, we noted that the schwannoma was in continuity with the common peroneal nerve. The patient underwent excision of the schwannoma. Post operatively, the pain reduced remarkably but patient suffers from numbness and right foot drop as a complication of the tumour. This case highlights the rarity of common peroneal nerve schwannoma which presents with neuropathic symptoms complicated with right foot drop.

Neurofibroma Cantal Solitario: Reporte de Caso / Canthal Solitary Neurofibroma

Objetivos: presentar el caso de una paciente que desarrolló un neurofibroma solitario de localización cantal interna. Diseño de estudio: reporte de caso. Métodos: se reporta el caso de una paciente con un neurofibroma solitario localizado en el canto interno, a la vez que se presenta una breve revisión bibliográfica sobre esta patología infrecuente. Conclusiones: el neurofibroma solitario es una patología infrecuente de naturaleza benigna que puede comprometer el globo ocular, el párpado y la órbita, por lo que debe ser considerado dentro de los diagnósticos diferenciales de la patología tumoral de estas áreas anatómicas.

Objectives: to report the case of a patient with a solitary neurofibroma in the medial canthal area. Study design: case report. Methods: report the case of a patient with a solitary neurofibroma in the medial canthal area and review the pertinent literature. Conclusions: the solitary neurofibroma is a rare benign condition with the potential to compromise the eye, the eyelid and the orbit, so that should be considered in the differential diagnosis of tumoral pathology in these anatomic areas. Keywords: nerve sheath neoplasms, peripheral nervous system neoplasms, neurofibroma.

Sequestered lumbar disc herniation mimicking spinal tumor / Hérnia de disco lombar sequestrada simulando tumor espinhal

The occurrence of herniated disc simulating diseases in neuroimaging it?s an uncommon situation. However, due to changes that occur in sequestered disc fragment, some cases can mimic spinal neoplasms. Thus, we present the case of a female patient, 60 year-old, with left back pain and left leg weakness. Left lower limb presented with strength grade IV, positive 45 degress Lasègue?s signal and patellar areflexia. Lumbar spine magnetic resonance imaging (MRI) showed an expansive left centro-lateral lesion at L4-L5 level, hypointense on T1W, hyperintense on T2W, with peripheral contrast uptake, causing compression of the dural sac and L5 nerve root. A hemilaminectomy was performed, with complete excision of the lesion. Histological analisys confirmed discal hernia. Disc herniation is a condition characterized by the displacement of the disc content to the spinal canal, predominantly in the lumbar region, and manifesting as radiculopathy. The fragment sequestration occurs in 30% of the cases and is characterized by loss of continuity with remaining disc. MRI exams generally allow diagnostic confirmation; however, there may be diagnostic confusion with tumors, arachnoid cysts and abscesses. The inflammatory reaction occurred in the disc fragment produces the differences in MRI signal. The fragment is hypointense on T1W, hyperintense on T2W, with peripheral enhancement after contrast. Malignancies and Schwannomas have homogeneous or heterogeneous uptake. The epidural abscess is isointense on T1W and hyperintense on T2W, with homogeneous or peripheral enhancement, similar to discal herniation. Thus, sequestered disc herniation can mimic other space-occupying lesions, being necessary a surgical approach to obtain material for histopathological analysis and diagnostic confirmation.

A ocorrência de hérnias de disco simulando outras patologias em neuroimagens é incomum. Entretanto, devido às alterações que ocorrem no fragmento discal sequestrado, alguns casos podem mimetizar neoplasias espinais. Assim, apresentamos o caso de uma paciente do sexo feminino, 60 anos, com lombalgia à esquerda e fraqueza na perna esquerda. O membro inferior esquerdo apresentava força grau IV, sinal de Laségue positivo a 45 graus e arreflexia patelar. Ressonância nuclear magnética (RNM) de coluna lombossacra evidenciou lesão expansiva centrolateral esquerda ao nível de L4-L5, hipointensa em T1, hiperintensa em T2, com captação periférica de contraste, determinando compressão do saco dural e raiz de L5. Realizou-se hemilaminectomia com excisão completa da lesão. A análise histológica confirmou hérnia discal. Hérnia de disco é uma patologia caracterizada pelo deslocamento do conteúdo discal para o canal vertebral, predominando na região lombar e manifestando-se como radiculopatia. O sequestro do fragmento ocorre em 30% dos casos e se caracteriza por perda da continuidade com o disco remanescente. Exames de RNM geralmente permitem a confirmação diagnóstica, entretanto, pode haver confusão diagnóstica com tumores, cistos aracnóideos e abscessos. A reação inflamatória ocorrida no fragmento discal produz as diferenças de sinal na RNM. O fragmento é hipointenso em T1, hiperintenso em T2, apresentando realce periférico após contraste. Neoplasias malignas e Schwannomas apresentam captação homogênea ou heterogênea. Os abscessos epidurais podem apresentar realce homogêneo ou periférico, semelhante às hérnias discais. Assim, hérnias de disco sequestradas podem mimetizar outras lesões ocupando espaço, sendo necessária abordagem cirúrgica com obtenção de material para análise histopatológica para confirmar o diagnóstico.

A Soft Tissue Perineurioma and a Hybrid Tumor of Perineurioma and Schwannoma

Perineuriomas are composed of differentiated perineurial cells. Perineuriomas have been recently recognized by the immunoreactivity for epithelial membrane antigen (EMA). Microscopically, perineuriomas show proliferation of spindle cells with wavy nuclei and delicate elongated bipolar cytoplasmic processes. The tumor cells are usually negative for the S-100 protein. Ultrastructurally, perineurial cells reveal slender, nontapered processes containing pinocytic vesicles and discontinuous basal lamina. Interestingly, hybrid tumors of benign peripheral nerve sheath tumor (PNST) have been recently reported by using immunohistochemical and ultrastructural investigations. Herein, we report a case of soft tissue perineurioma arising in the skin of a 56-year-old female; another case of a hybrid tumor of perineurioma and schwannoma in the posterior mediastinum occurred in a 53-year-old male, which is the first case of the hybrid PNST tumor reported in Korea.

Tumor maligno de la vaina del nervio periférico del mediastino en un paciente con neurofibromatosis tipo 1 / Mediastinal malignant peripheral nerve sheath tumor in a neurofibromatosis type 1 patient

El tumor maligno de la vaina del nervio periférico (TMVNP), es una neoplasia maligna originada en las células de Schwan de la vaina de revestimiento del nervio periférico. Describir el caso de un hombre con neurofibromatosis tipo 1 (NF1), quién presentó un TMVNP de bajo grado, y realizar una discusión sobre esta enfermedad. Hombre de 28 años, con antecedente de NF1 diagnosticada a los 15 años de edad, con dolor pleurítico izquierdo, disnea y pérdida de peso de 10 meses de evolución. Al examen de tórax, se observó marcada hipercifosis dorsal con disminución del murmullo pulmonar. La radiografía de tórax y tomografía axial computarizada (TAC), evidenciaron gran masa radioopaca bien delimitada en mediastino posterior. Por lo anterior, se realizo biopsia por punción con aguja gruesa guiada por TAC, en la cual se identificó una neoplasia maligna mesenquimal. Se decidió realizar resección del tumor a través de toracotomía posterolateral, en la que se obtuvo gran masa de 8x9x9 cm, de superficie externa irregular, pardo-violácea y consistencia firme. El estudio histopatologico e inmunofenotípico concluyo el diagnóstico de TMVNP en mediastino posterior Grado 1. Posterior a la cirugía, el paciente se encuentra asintomático. Se presentó un caso de TMVNP originado en un paciente con NF1, presentación que generalmente cursa con peor pronóstico, además se realizo una breve revisión de los aspectos más relevantes de esta enfermedad, algunos de los cuales han tenido un avance vertiginoso en años recientes.

The malignant peripheral nerve sheath tumor (MPNST) is a malignant neoplasm originated in the Schwan cells of the periferic nerves sheath. We describe a case of a man with Neurofibroatosis Type 1 (NF1), who developed a low grade MPNST, and subsequent to a discussion of this disease. 28-year-old Man with pleuritic pain in the left hemithorax, dyspnea and weight loss, with a previous diagnosis of NF1, from the age of 15 and a family history of NF1. At chest examination the patient had an intense thoracic kyphosis, with a decline in the ventilation of the inferior two thirds of the left hemithorax, where a dull sound to percusión was also found. The chest X rays showed a large radiopaque and well delimited mass in the posterior mediastinum, that pushed the cardiovascular structures to the anterior region, which was also documented by chest computed tomography (CT). In view of the above, a puncture biopsy was performed with thick needle guided by CT, from where a malignant mesenhymal neoplasm was identified. It was decided to perform the resection of the tumor of the left posterior mediastinum, by left posterior lateral thoracotomy, in which a large mass of 8x9x9 cm was obtanied, with irregular external surface, brown-violet, and firm. The histopathological and inmunophenotypic study concluded the diagnosis of MPNST in the posterior mediastinum grade 1. Following surgery the patient was asymptomatic. We present a case of MPNST which originated in a patient with NF1, who would usually have a worse prognosis. A brief review of the more relevant aspects of this disease was also reported, some of which have shown important progress in recent years.

Ileal perineurioma as a cause of intussusception / Perineurioma ileal como uma causa de intussuscepção

CONTEXT: Perineuriomas are rare tumors composed of cells resembling those of the normal perineurium. It usually occurs in subcutaneous, soft-tissue or intraneural locations. Very few reports in the literature have described perineuriomas in the gastrointestinal tract, including the stomach, colon and jejunum. CASE REPORT: We report the clinicopathological and immunohistochemical features of a case of ileal perineurioma that was manifested clinically as intestinal obstruction due to intussusception. Ileal perineurioma has not previously been reported at this anatomical location.

CONTEXTO: Perineurioma é uma rara neoplasia composta de células que lembram aquelas do perineuro normal e geralmente ocorre no subcutâneo, tecidos moles ou em localização intraneural. Poucos relatos na literatura descrevem perineuriomas no trato gastrointestinal incluindo estômago, cólon e jejuno. RELATO DE CASO: Os autores apresentam as características clinicopatológicas e imunoistoquímicas de um caso de perineurioma ileal apresentando-se clinicamente por obstrução intestinal decorrente de intussuscepção. Perineurioma ileal não havia sido descrito até o momento nessa localização anatômica.

A Case of Facial Nerve Schwannoma Presenting as an External Auditory Canal Mass

Facial nerve schwannoma is a rare benign tumor that arises from the Schwann cell sheath of facial nerve. Although the tumor can occur anywhere along the course of the peripheral nerve, it is frequently present as an internal auditory canal mass in the head and neck region. We experienced a rare case of facial nerve schwannoma on the mastoid segment, which was presented as an external auditory canal mass in a 24-years-old man. The lesion was removed via the transmastoid approach and the facial nerve was grafted using the greater auricular nerve. The patient's facial nerve function was preserved postoperatively as House-Brackmann grade III.

Loss of Y Chromosome in the Malignant Peripheral Nerve Sheet Tumor of a Patient with Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is one of the most commonly inherited autosomal dominant disorders. In order to determine whether genomic alterations and/or chromosomal aberrations involved in the malignant progression of NF1 were present in a Korean patient with NF1, molecular and cytogenetic analyses were performed on the pathologically normal, benign, and malignant tissues and primary cells cultured from those tissues of the patient. The comparative genomic hybridization (CGH) array revealed a Y chromosome loss in the malignant peripheral nerve sheet tumor (MPNST) tissue. G-banding analysis of 50 metaphase cells showed normal chromosomal patterns in the histopathologically normal and benign cultured cells, but a mosaic Y chromosome loss in the malignant cells. The final karyotype for the malignant cells from MPNST tissue was 45,X,-Y[28]/46,XY[22]. The data suggest that the somatic Y chromosome loss may be involved in the transformation of benign tumors to MPNSTs.

A Case of Malignant Peripheral Nerve Sheath Tumor of the Neck Associated with Neurofibromatosis Type I / 대한이비인후과학회지

Neurofibromatosis is an autosomal dominant hereditary disorder characterized by skin abnormalities such as cafe au-lait spots, and soft tissue legion such as generalized subcutaneous neurofibroma. Malignant peripheral nerve sheath tumor is a spindle cell sarcoma that mostly arises in the soft tissue but rarely arises in the head and neck region. Malignant peripheral nerve sheath tumor can develop from the pre-existing neurofibromas or schwannomas, and from the peripheral nerves. They can also occur after radiation therapy. Malignant peripheral nerve sheath tumor is usually associated with neurofibromatosis type I. The authors recently experienced a case of malignant peripheral nerve sheath tumor associated with neurofibromatosis type I in a 20-year-old female patient who presented with a well marginated oval shape mass in the left neck.

Perineurioma esclerosante: relato de caso e revisão da literatura / Sclerosing perineurioma: case report and literature review

O perineurioma esclerosante é uma neoplasia benigna rara,constituída exclusivamente por células com diferenciação perineural, dispersas em meio a estroma fibroso denso. Acomete preferencialmente a pele dos quirodáctilos e das regiões palmares e se apresenta como pápula ou nódulo firme, normocrômico e assintomático. Apresentamos um caso de perineurioma esclerosante localizado na região palmar esquerda de uma paciente feminina de 16 anos de idade, com detalhada demonstração dos aspectos clínicos, histopatologia e revisão da literatura publicada em língua inglesa.

Sclerosing perineurioma is a rare benign neoplasm composed exclusively of perineural differentiation cells spread in a dense fibrous stroma. It affects primarily the skin of fingers and that of the palm of the hands. It appears as a hard papule or nodule, normochromic and asymptomatic. A case of sclerosing perineurioma in the left palm of a 16-year-old female is described, with detailed demonstration of clinical aspects, histopathology and literature review published in the English language.

Um caso raro de tumores torácicos malignos sincrônicos / A rare case of synchronous malignant thoracic tumors

Tumores neurogênicos malignos do mediastino em adultos são raros e extremamente agressivos. Este artigo relata o caso de um paciente de 61 anos com a ocorrência simultânea de schwannoma maligno de mediastino e carcinoma bronquíolo-alveolar. Apesar do carcinoma bronquíolo-alveolar estar presente em 4-7 por cento dos tumores torácicos sincrônicos ressecados, essa associação nunca foi apresentada na literatura. É, no entanto, um achado frequente em pacientes com infiltrados aparentemente inflamatórios e com opacidades em vidro fosco, como apresentado neste caso.

Malignant neurogenic mediastinal tumors in adults are uncommon and extremely aggressive. We report the case of a 61-year-old male patient with the simultaneous occurrence of malignant mediastinal schwannoma and bronchioloalveolar carcinoma. Although bronchioloalveolar carcinoma is present in 4-7 percent of the resected synchronous thoracic tumors, this association has never been reported in the literature. However, it is a common finding in patients presenting apparently inflammatory infiltrates and ground-glass opacities, as in the case presented here.

Retrospective analysis of oral peripheral nerve sheath tumors in Brazilians

Traumatic neuroma, neurofibroma, neurilemmoma, palisaded encapsulated neuroma and malignant peripheral nerve sheath tumor (MPNST) are peripheral nerve sheath tumors and present neural origin. The goal of this study was to describe the epidemiological data of oral peripheral nerve sheath tumors in a sample of the Brazilian population. Biopsies requested from the Oral Pathology Service, School of Dentistry, Federal University of Minas Gerais (MG, Brazil), between 1966 and 2006 were evaluated. Lesions diagnosed as peripheral nerve sheath tumors were submitted to morphologic and to immunohistochemical analyses. All cases were immunopositive to the S-100 protein. Thirty-five oral peripheral nerve sheath tumors were found, representing 0.16% of all lesions archived in the Oral Pathology Service. Traumatic neuroma (15 cases) most frequently affected the mental foramen. Solitary neurofibroma (10 cases) was more frequently observed in the palate. Neurofibroma associated with neurofibromatosis type I (2 cases) was observed in the gingival and alveolar mucosa. Neurilemmoma (4 cases) was more commonly observed in the buccal mucosa. Malignant peripheral nerve sheath tumors (3 cases) occurred in the mandible, palate, and tongue. Palisaded encapsulated neuroma (1 case) occurred in the buccal mucosa. The data confirmed that oral peripheral nerve sheath tumors are uncommon in the oral region, with some lesions presenting a predilection for a specific gender or site. This study may be useful in clinical dentistry and oral pathology practice and may be used as baseline data regarding oral peripheral nerve sheath tumors in other populations.

Malignant Peripheral Nerve Sheath Tumor of the Breast in a Patient without Neurofibromatosis: A Case Report / 한국유방암학회지

Malignant peripheral nerve sheath tumors (MPNSTs) are malignant variants of peripheral nerve sheath tumors that develop at major or minor peripheral nerve branches or at the sheaths of peripheral nerve fibers. These tumors are derived from Schwann cells or pluripotent cells of a neural crest origin. Malignant tumors of the peripheral nerve sheath are most commonly seen in deeper soft tissues, and usually in the proximity of a nerve trunk. MPNSTs of the breast are very uncommon and they have rarely been reported on. We report here on a case of MPNST of the breast in a 59-year-old female who presented with a painless breast lump for two months. The excisional biopsy revealed a malignant peripheral nerve sheath tumor based on the microscopic findings and immunohistochemical staining. We performed wide excision of breast tissue around the biopsy site and thereafter the patient underwent radiation therapy. The patient remains well without signs of recurrence 1 year following surgery.

A Case of Ancient Schwannoma of the Submandibular Gland / 대한이비인후과학회지

Ancient schwannoma is a benign neoplasm of nerve origin and may cause difficulties in the differential diagnosis with other benign or malignant tumors. It is also a rare variant of schwannoma with atypical tumor cells with nuclear pleomorphism and hyperchromatism. In this report, a 44-years-old female patient with an ancient schwannoma of the submandibular gland is presented, discussed, and the literature is reviewed for head and neck location of this tumor.