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.
Diagnosis, Differential ; Head ; Humans ; Magnetic Resonance Imaging ; Neck ; Nerve Sheath Neoplasms ; Neurilemmoma ; Peripheral Nerves ; Schwann Cells ; Tongue

Biopsy ; Humans ; Male ; Middle Aged ; Muscle Neoplasms ; diagnosis ; pathology ; Neoplasm Metastasis ; Nerve Sheath Neoplasms ; diagnosis ; pathology ; Recurrence ; Sciatic Nerve ; pathology ; Tomography, X-Ray Computed

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.
Brachial Plexus Neuropathies ; Brachial Plexus ; Classification ; Diagnosis ; Humans ; Intraoperative Neurophysiological Monitoring ; Monitoring, Intraoperative ; Nerve Sheath Neoplasms ; Neurilemmoma ; Neurofibroma ; Neurosurgeons ; Pathology ; Peripheral Nerves ; Postoperative Complications ; Retrospective Studies

Schwannomas are benign nerve sheath tumors that are typically located in soft tissue. Occasionally, schwannomas involve osseous structures. These intraosseous schwannomas are generally benign neoplasms that account for less than 0.2% of primary bone tumors. Schwannomas are very rarely observed in long bones. We present a case of a schwannoma affecting the proximal femur with a coincident subchondral fracture of the femoral head. A 38-year-old-male presented with left hip pain without deteriorating locomotor function. Plain film radiographs displayed a lobulating contoured lesion within the intertrochanteric portion of the femur. The magnetic resonance imaging (MRI) scans showed a tumor occupying the intertrochanteric region. Diffuse bone marrow edema, especially in the subchondral and head portions of the femur that was possibly due to the subchondral insufficiency fracture was also noted. The lesion was surgically excised and bone grafting was performed. Histologically, there was diffuse infiltrative growth of the elongated, wavy, and tapered cells with collagen fibers, which are findings that are characteristic of intraosseous schwannoma. Although very rare, intraosseous schwannoma should be included in the differential diagnosis of radiographically benign-appearing, non-aggressive lesions arising in the femur. The concomitant subchondral fracture of the femoral head confounded the correct diagnosis of intraosseous schwannoma in this case.
Bone Marrow ; Bone Transplantation ; Collagen ; Diagnosis ; Diagnosis, Differential ; Edema ; Femur ; Fractures, Stress ; Head* ; Hip ; Magnetic Resonance Imaging ; Nerve Sheath Neoplasms ; Neurilemmoma*

Neurofibromas are benign, slow-growing nerve sheath tumors of the peripheral nervous system, arising from Schwann cells, and classically associated with neurofibromatosis type 1 (Nf1, von Recklinghausen's disease). They occur rarely in the gastrointestinal tract as isolated neoplasms, outside the classical clinical feature of neurofibromatosis. We herein present an isolated colonic neurofibroma without any systemic signs of neurofibromatosis. A 59-year-old female came to our hospital for constipation. On physical examination, general appearance showed no definite skin lesions. A subepithelial tumor measuring 0.8 cm was detected at the distal descending colon on colonoscopy. The lesion was removed completely by endoscopic resection. Microscopic examination showed proliferation of spindle cells in the mucosa and infiltration of inflammatory cells. Immunohistochemical staining was positive for S-100 protein. The above morphological and immunohistochemical characteristics were consistent with a diagnosis of a solitary neurofibroma of the sigmoid colon.
Colon ; Colon, Descending ; Colon, Sigmoid* ; Colonoscopy ; Constipation ; Diagnosis ; Female ; Gastrointestinal Tract ; Humans ; Middle Aged ; Mucous Membrane ; Nerve Sheath Neoplasms ; Neurofibroma* ; Neurofibromatoses ; Neurofibromatosis 1 ; Peripheral Nervous System ; Physical Examination ; S100 Proteins ; Schwann Cells ; Skin

Schwannomas are benign peripheral nerve sheath tumors. It is found rarely in the oral cavity but most commonly in the tongue followed by the palate, floor of mouth, buccal mucosa, and mandible. Because schwannoma of the base of tongue is exceedingly rare, it is often not immediately included in the differential diagnosis, causing delay in identification and treatment. We report here, with a review of the literature, a case of schwannoma of the base of tongue, which was misdiagnosed as a lingual thyroid. A 28-year-old man presented with a base of tongue mass, which was first detected a month ago. The preoperative diagnosis was lingual thyroid on the basis of the physical findings and computerized tomographic findings. The permanent pathologic report of the mass was schwannoma. Postoperatively, the patient showed no problem with tongue function and wound healing.
Adult ; Diagnosis ; Diagnosis, Differential ; Humans ; Lingual Thyroid ; Mandible ; Mouth ; Mouth Floor ; Mouth Mucosa ; Nerve Sheath Neoplasms ; Neurilemmoma* ; Palate ; Tongue* ; Wound Healing

PURPOSE: To identify the differential MRI findings between myxoid tumors and benign peripheral nerve sheath tumors (BPNSTs) in the musculoskeletal system. MATERIALS AND METHODS: The study participants included a total of 35 consecutive patients who underwent MRI between September 2011 and December 2013. The patients were pathologically diagnosed with myxoid tumors (22 patients) or BPNSTs (13 patients). Evaluation was done by two radiologists, based on the following characteristics: size, margin, degree of signal intensity (SI) on T2-weighted images (T2WI), homogeneity of SI on T2WI, enhancement pattern, enhancement homogeneity, presence of cystic portion, internal fat component, presence of fat split sign, presence of target sign, presence of continuation with adjacent neurovascular bundle, and presence of surrounding halo. RESULTS: Large size, high SI on T2WI, heterogeneous enhancement, and internal fat component were commonly observed in myxoid tumors, while homogenous enhancement, fat split sign, target sign were common in BPNSTs. The differences were statistically significant (P < 0.05). Other findings, such as margin, homogeneity of SI on T2WI, enhancement pattern (peripheral or solid), internal cystic portion, continuation with neurovascular bundle, and surrounding halo, did not show significant difference between myxoid tumors and BPNSTs (P > 0.05). CONCLUSION: In the differential diagnosis of myxoid tumors and BPNSTs involving the musculoskeletal system, several MRI findings such as degree of SI on T2WI, enhancement homogeneity, internal fat component, fat split sign, and target sign, may be helpful in establishing the diagnosis.
Diagnosis ; Diagnosis, Differential ; Humans ; Magnetic Resonance Imaging* ; Musculoskeletal System* ; Nerve Sheath Neoplasms* ; Peripheral Nerves*

Peripheral nerve sheath tumors (PNSTs) are heterogeneous tumor groups of peripheral nerves that originate from either Schwann cells or modified Schwann cells, fibroblasts, or perineural cells. In this study, signalment and clinical data such as tumor location and size were evaluated for 15 cases of PNSTs collected from local animal hospitals. The mean age of dogs with malignant PNST was higher than that of dogs with benign PNST. Additionally, the male to female ratio in dogs with PNST was 1 : 4. In dogs with PNST, the primary sites of involvement were the hindlimb, forelimb, around the mammary glands, the neck, and the abdomen. Histiopathologic examination revealed that eight PNSTs were benign and seven were malignant. The tumor cells were composed of loosely to densely arranged interlacing bundles and wavy spindle cells arranged in short bundles, palisading, and whirling. High mitotic figures, local invasion, multifocal necrosis and atypical multinucleated giant cells were observed in malignant PNST cases. All PNSTs showed immunoreactivity for vimentin and S-100. However, only 93.3% and 73.3% were immunoreactive for NSE and GFAP, respectively. Overall, these results indicated that immunohistochemical markers such as vimentin, S-100 and NSE could help confirm the diagnosis of canine PNSTs.
Abdomen ; Animals ; Diagnosis ; Dogs* ; Female ; Fibroblasts ; Forelimb ; Giant Cells ; Hindlimb ; Hospitals, Animal ; Humans ; Immunohistochemistry ; Male ; Mammary Glands, Human ; Neck ; Necrosis ; Nerve Sheath Neoplasms* ; Peripheral Nerves* ; Schwann Cells ; Vimentin

Adult ; Diagnosis, Differential ; Female ; Fibroma ; metabolism ; pathology ; Fingers ; Giant Cell Tumors ; metabolism ; pathology ; Humans ; Mucin-1 ; metabolism ; Nerve Sheath Neoplasms ; metabolism ; pathology ; surgery ; Neurilemmoma ; metabolism ; pathology ; Sclerosis ; metabolism ; pathology ; Soft Tissue Neoplasms ; metabolism ; pathology ; surgery ; Tendons ; Young Adult

Diagnosis, Differential ; Fetus ; Fibroma ; metabolism ; pathology ; Fibrosarcoma ; congenital ; genetics ; metabolism ; secondary ; Hemangiopericytoma ; metabolism ; pathology ; Humans ; Kidney Neoplasms ; pathology ; secondary ; Liver Neoplasms ; pathology ; secondary ; Lung Neoplasms ; pathology ; secondary ; Male ; Nerve Sheath Neoplasms ; metabolism ; pathology ; Rhabdomyosarcoma, Embryonal ; metabolism ; pathology ; Soft Tissue Neoplasms ; congenital ; genetics ; metabolism ; pathology ; Vimentin ; metabolism