UNASSIGNED: Although hemorrhages associated with cervical and thoracic intraspinal schwannomas are typically localized to the subarachnoid hemorrhages (SAH) or subdural hemorrhages (SDH) compartments, rare intratumoral bleeds may also occur.
UNASSIGNED: In the literature, we found and analyzed multiple factors for 13 cases (e.g., epidemiological, clinical, and pathological) of cervical schwannomas with intratumoral hemorrhages (ITH). We added the 14th case of a 35-year-old female with along segment cervical schwannoma with ITH who presented with acute quadriplegia and respiratory decompensation.
UNASSIGNED: These 14 patients averaged 51.77 years of age, 60% were male, and the tumor involved 2.83 segments. The incidence of SAH and ITH was noted in five cases each, while SDH\'s were very rare. The pathological characteristics were consistent with the diagnosis of cellular schwannomas with S-100 positivity. The clinical outcomes were good (100%) in all the cases, including the one presented (modified McCormick score III).
UNASSIGNED: Cervical schwannomas with ITH are rare, and the surgical outcomes in such patients are good-excellent (>90%). The histopathology is always of prime importance and decisive in establishing and confirming the etiology of such ITH.

OBJECTIVE: Cellular schwannoma is a specific subtype of schwannoma, prone to misinterpretation as a malignant neoplasm. Involvement of the intracranial compartment by these tumours is extremely rare. We aim to characterise this clinicopathological subgroup.
RESULTS: We identified a total of 20 cellular schwannomas with predominant intracranial involvement. The mean age of the patients at the time of surgery was 37 years (range = 16-81), with a slight female predominance (1.5:1 ratio). The most common sites were the eighth (n = 8) and fifth (n = 6) cranial nerves. Three tumours involved the anterior cranial fossa/olfactory groove, and a single case involved the glossopharyngeal nerve. All tumours met established criteria for cellular schwannoma, and were composed of interlacing fascicles of spindle cells lacking Verocay bodies with minimal Antoni B pattern and variable chronic inflammation and foamy histiocytes. Rare findings included haemosiderin deposition (n = 6), necrosis (n = 4), brisk mitotic activity (>10 mitoses per 10 high-power fields) (n = 2), focal epithelioid morphology (n = 2), myxoid areas (n = 2), neuroblastoma-like pattern (n = 1) and granular cells (n = 1). Immunohistochemical stains demonstrated expression of Schwann cell markers (S100 protein, SOX10, collagen IV) and preserved H3 K27 trimethylation in all cases tested. Fourteen patients had postoperative follow-up, ranging from 2 months to 21 years (mean = 66 months). In patients with follow-up, local recurrence/persistence developed in six cases; five tumours were initially incompletely resected. No metastatic disease or deaths were reported.
CONCLUSIONS: Intracranial cellular schwannomas share morphological and immunophenotypical features with cellular schwannomas at others sites may demonstrate locally aggressive growth but appear to lack metastatic potential.

Neurofibromatosis type II (NF2) is a tumor predisposition syndrome characterized by the development of distinctive nervous system lesions. NF2 results from loss-of-function alterations in the NF2 gene on chromosome 22, with resultant dysfunction of its protein product merlin. NF2 is most commonly associated with the development of bilateral vestibular schwannomas; however, patients also have a predisposition to development of other tumors including meningiomas, ependymomas, and peripheral, spinal, and cranial nerve schwannomas. Patients may also develop other characteristic manifestations such as ocular lesions, neuropathies, meningioangiomatosis, and glial hamartia. NF2 has a highly variable clinical course, with some patients exhibiting a severe phenotype and development of multiple tumors at an early age, while others may be nearly asymptomatic throughout their lifetime. Despite the high morbidity associated with NF2 in severe cases, management of NF2-associated lesions primarily consists of surgical resection and treatment of symptoms, and there are currently no FDA-approved systemic therapies that address the underlying biology of the syndrome. Refinements to the diagnostic criteria of NF2 have been proposed over time due to increasing understanding of clinical and molecular data. Large-population studies have demonstrated that some features such as the development of gliomas and neurofibromas, currently included as diagnostic criteria, may require further clarification and modification. Meanwhile, burgeoning insights into the molecular biology of NF2 have shed light on the etiology and highly variable severity of the disease and suggested numerous putative molecular targets for therapeutic intervention. Here, we review the clinicopathologic features of NF2, current understanding of the molecular biology of NF2, particularly with regard to central nervous system lesions, ongoing therapeutic studies, and avenues for further research.

Schwannomas of the hand are very rare tumors and represent less than 3% of all soft tissue tumors in the hand. These tumors share clinical, epidemiological and imaging characteristics with the other soft tissue and peripheral nerve tumors; thus, it can be difficult to make a preoperative diagnosis. Here we report the case of a 48-year-old woman who presented with a schwannoma arising from the palmar branch of the median nerve. The tumor measured 54 × 41 x 52 mm and was located in the thenar eminence. The first hypothesis was a vascular tumor. After surgery and histological analysis, the final diagnosis of an atypical schwannoma was established. The presence of shared immunohistochemical characteristics with cellular histiocytoma and myoepithelial tumors forced us to adopt an aggressive follow-up protocol. As of the last follow-up at 9 years, the patient had good clinical outcomes and no recurrence. This case highlights the difficulties encountered in clinical practice to diagnose such tumors.

BACKGROUND: Malignant peripheral nerve sheath tumors (MPNSTs) and cellular schwannomas (CSs) of the eighth cranial nerve are exceedingly rare. The purpose of the present study was to evaluate clinical and genetic characterization of these rare tumors.
METHODS: The clinical and radiological features were analyzed retrospectively. The histopathological characteristics were assessed by hematoxylin and eosin staining and immunohistochemistry. Genomic abnormalities were evaluated using array comparative genomic hybridization.
RESULTS: Of the 1287 surgeries for vestibular schwannomas from 2014 to 2017, 2 were for MPNSTs and 5 were for CSs. The mean age at diagnosis was older for patients with MPNSTs (57.0 ± 4.2 years) than that of patients with CS (35.8 ± 9.4 years; P = 0.03). Two patients with MPNST died of tumor recurrence. None of the patients with CS died. The 2-year overall and progression-free survival of patients with MPNSTs were worse than those for patients with CSs (overall survival, 50.0% ± 35.4% vs. 100%, P = 0.027; progression-free survival, 0% vs. 100%; P = 0.012). The Ki-67 index for the MPNSTs (29.0% ± 3.5%) was greater than that for the CSs (10.3% ± 3.1%; P = 0.001). The common alterations in MPNSTs mainly included gains of chromosomes 7p, 8p, 9q, 12, and 17 and loss of heterozygosity of 1p, 6 and 9p. The common alterations in CSs included gain of 4p16.3, loss of heterozygosity of 2p15-14, and 22q11.1-13.3.
CONCLUSIONS: To the best of our knowledge, the present study is the first high-resolution genomic analysis of MPNSTs and CSs of the eighth cranial nerve and has shown a significant difference that might be more accurate to distinguish between these 2 types of rare tumors.

Neoplasm in sinonasal cavity is dominated by epithelial type. Sinonasal schwannoma is a rare entity represent less than four percent of head and neck schwannoma. Clinically this tumour is commonly misdiagnosed until they are confirmed by histopathological examination. We present a case of schwannoma in sinonasal region with involvement of right side nasal cavity, maxillary sinus and maxillary alveolar process. The tumour was successfully removed by midfacial degloving approach.