Report of 2 cases
Da Li, Shu-Yu Hao, Zhen Wu, Li-Wei Zhang and Jun-Ting Zhang
Medulla oblongata teratomas are rare. The authors report 2 new cases of teratomas that occurred exclusively in the medulla oblongata. The first case was in a 9-year-old boy who presented with a 6-month history of neck pain and repeated paroxysmal vomiting. Based on preoperative radiographic findings, the initial diagnosis was of an intraaxial medulla oblongata hemangioblastoma. Intraoperatively, the cystic component of the tumor was gray, gelatinous, and soft in consistency. The solid component was light pink, rubbery, and nodular in appearance, with an identifiable boundary. The lesion was completely removed. Histopathological investigation revealed a mature teratoma. Postoperatively, the patient was supported with ventilator assistance and received a tracheotomy, but died of intracranial infection. The second case was in a 10-year-old boy with intermittent headache for 1 month. Radiographs revealed an exophytic cystic and solid lesion with dorsal involvement of the medulla oblongata. The lesion was predominantly solid, pinkish gray, tenacious, and moderately vascularized, with clearly delineated surgical dissection planes. The histopathological examination confirmed a diagnosis of immature teratoma. Total resection was achieved, followed by postoperative chemotherapy. He was alive without recurrence of the lesion or symptoms at 59 months after surgery.
Resection of medulla oblongata teratoma is challenging, with inherent surgical risks that are contingent on the tumor growth pattern. Teratomas should be considered in the differential diagnosis of brainstem lesions. Chemotherapy has been suggested for immature teratomas. Long-term follow-up and larger studies of teratomas in unusual locations are required to improve practitioners' understanding of this disease's treatment and outcomes.
Cheng-Bei Li, Lai-Rong Song, Da Li, Jian-Cong Weng, Li-Wei Zhang, Jun-Ting Zhang and Zhen Wu
The overall survival and pertinent adverse factors for primary intracranial malignant melanoma (PIMM) have not been previously determined. This aim of this study was to determine the rates of progression-free survival (PFS) and overall survival (OS) and identify the adverse factors for PIMM.
This study included 15 cases from the authors’ own series and 100 cases with detailed clinical data that were obtained from the literature from 1914 to 2018 using the Ovid Medline, EMBASE, PubMed, Cochrane, and EBSCO databases. Patient demographics, treatment (surgery, chemotherapy, and radiotherapy [RT]), PFS, and OS were reviewed. Data from prior publications were processed and used according to PRISMA guidelines.
Diffuse lesions were identified in 24 (20.9%) patients, who had a younger age (p < 0.001). The mean follow-up time was 16.6 months, and 76 (66.1%) deaths occurred. The 6-month, 1-year, 3-year, and 5-year OS rates of the whole cohort were 62.8%, 49.9%, 28.9%, and 17.2%, respectively, with an estimated median survival time (EMST) of 12.0 months. The multivariate analysis revealed that gross-total resection (GTR) (HR 0.299, 95% CI 0.180–0.497, p < 0.001), radiotherapy (HR 0.577, 95% CI 0.359–0.929, p = 0.024), and chemotherapy (HR 0.420, 95% CI 0.240–0.735, p = 0.002) predicted a better OS. The EMST was 5.0 months in patients with diffuse-type PIMM and 13.0 months in patients with the solitary type. Patients receiving GTR with adjuvant RT and/or chemotherapy (GTR + [RT and/or chemo]) had significantly higher 1-year and 5-year OS rates (73.0% and 40.1%, respectively) and a longer EMST (53 months) than patients who underwent GTR alone (20.5 months) or RT and/or chemotherapy without GTR (13.0 months).
Optimal outcomes could be achieved by radical resection plus postoperative radiotherapy and/or chemotherapy. Patients with diffuse PIMM have a more severe clinical spectrum and poorer survival than patients with solitary PIMM. Immunotherapy and targeted therapy show promise as treatment options for PIMM based on results in patients with brain metastases from extracranial melanoma.
Song-tao Qi, Jun Fan, Xi-an Zhang and Jun Pan
A precise understanding of the ambient cistern and its associated arachnoid membranes is helpful for accessing perimesencephalic lesions. However, few studies of the arachnoid membranes related to the ambient cistern have been published, and, additionally, some aspects of the ambient cistern also require further examination. The goal of this study was to reinvestigate and expound on the anatomical features of the cistern and membranes.
The ambient cisterns and its associated arachnoid membranes were examined in 20 adult cadaveric brains using an operative microscope.
The perimesencephalic membrane is a set of inner arachnoid membranes surrounding the midbrain at the level of the tentorial incisura. It arises from the outer arachnoidal membranes covering the tentorial edge and the dorsum sellae and can be subdivided into anterior and posterior portions. The anterior membrane is actually the mesencephalic leaf of Liliequist membrane, which is divided into medial and lateral parts by the oculomotor nerve. The posterior membrane can be divided into horizontal and ascending parts. The ambient cistern is located above the perimesencephalic membrane and contains the anterior choroidal arteries, the posterior cerebral arteries, the basal vein, and sometimes the segments of the superior cerebellar arteries. It communicates with the carotid cistern, the interpeduncular cistern, the oculomotor cistern, the cerebellopontine and cerebellomesencephalic cistern, and the quadrigeminal cistern.
This study updates some information about the ambient cistern and its arachnoid membranes. The perimesencephalic membrane was identified and described in detail. The ambient cistern was verified to be a supratentorial cistern above the perimesencephalic membrane. The borders and contents of this cistern, as well as its relationship with adjacent cisterns, were also redefined.
Da Li, Shu-Yu Hao, Gui-Jun Jia, Zhen Wu, Li-Wei Zhang and Jun-Ting Zhang
Cerebral cavernous malformations have been studied widely, but the natural history of brainstem cavernous malformations (CMs) is not well defined, and hemorrhages caused by brainstem CMs are devastating. The goal of this study was to quantify the hemorrhage risks and functional outcomes of patients with brainstem CMs.
This prospective, longitudinal, cohort study included patients with brainstem CMs diagnosed between 1985 and 2012. The clinical courses of all patients were recorded. Predictors of hemorrhage and the overall untreated outcomes were evaluated.
A total of 331 patients (46.5% female) were included, with a mean follow-up duration of 6.5 years. The annual hemorrhage rates in patients initially presenting with hemorrhage with (n = 215) or without (n = 34) focal neurological deficits were 15.9% and 12.4%, respectively. However, the annual hemorrhage rate was 8.7% in patients initially presenting without hemorrhage (n = 82). The risk factors for hemorrhage were female sex (hazard ratio [HR] 1.445, p = 0.041), prior hemorrhage (HR 1.277, p = 0.029), and perilesional edema (HR 1.830, p = 0.002). Overall, neurological function at the most recent assessment was improved compared with neurological function at diagnosis. Additionally, 307 patients (92.7%) improved or stabilized, 268 (81.0%) lived independently, and 95 (28.7%) completely recovered. Predictors favoring complete recovery were no prospective hemorrhage (HR 1.958, p = 0.001), younger age (HR 1.268, p = 0.001), and small lesion size (HR 1.578, p = 0.004).
Patients' initial presentation predicts their prospective annual hemorrhage rate. This study suggests that several strong risk factors for hemorrhage and predictors of brainstem CM outcomes may enable clinicians to evaluate the potential hemorrhage risks of their patients and design personalized treatments.
Da Li and Jun-Ting Zhang
James Schuster, Jun Zhang and Maria Longo
One of the major difficulties of conducting bone metastasis research is the lack of adequate models for studying the bone–tumor microenvironment. The limitations of current in vivo models include the following: non-human tumor or bone, variable reproducibility, limited supply, and an inability to be easily manipulated. The objective of the present study was to develop a uniform and reproducible model of bone/spine metastasis by utilizing bone derived from human osteoblasts grown subcutaneously in severe combined immunodeficiency (SCID) mice with subsequent introduction of human carcinoma cell lines.
Human osteoblasts were serially passed in culture and induced to differentiate into mature osteoblasts. They were subsequently loaded on hydroxyapatite-coated collagen sponges and implanted subcutaneously into the SCID mice. After allowing the bone to mature for 8 weeks, tumor cell suspensions were implanted percutaneously into the bone. The bone–tumor complexes were subsequently harvested, decalcified, and prepared for histological examination.
The authors have developed a novel, reproducible SCID mouse model of bone/spine metastasis by using bone derived from human osteoblasts and subsequently introduced human tumor lines. They believe this model will be useful for studying the basic biology of bone metastases.
Jun Zhang, Ping-Heng Lan and Hai-Qiang Wang
Wei Liu and Jian-Guo Zhang
Liang-Hua Ma, Guang Li, Hong-Wei Zhang, Zhi-Yu Wang, Jun Dang, Shuo Zhang, Lei Yao and Xiao-Meng Zhang
This study was undertaken to analyze outcomes in patients with newly diagnosed brain metastases from non–small cell lung cancer (NSCLC) who were treated with hypofractionated stereotactic radiotherapy (HSRT) with or without whole-brain radiotherapy (WBRT).
One hundred seventy-one patients comprised the study population. Fifty-four patients received HSRT alone, and 117 patients received both HSRT and WBRT. The median survival time (MST) was determined using the Kaplan-Meier method. Recursive Partitioning Analysis (RPA) and Graded Prognostic Assessment (GPA) were also used to evaluate the results. Univariate and multivariate analyses were performed to determine significant prognostic factors for overall survival. Tumor control, radiation toxicity, and cause of death in the HSRT and HSRT+WBRT groups were evaluated.
The MST for all patients was 13 months. According to the Kaplan-Meier method, the probability of survival at 1, 2, and 3 years was 51.2%, 21.7%, and 10.1%. The MSTs for RPA Classes I, II, and III were 19, 12, and 5 months, respectively; and the MSTs for GPA Scores 4, 3, 2, and 1 were 24, 14, 12, and 6 months, respectively. The MSTs in the HSRT+WBRT and HSRT groups were 13 and 9 months (p = 0.044), respectively, for all patients, 13 and 8 months (p = 0.031), respectively, for patients with multiple brain metastases, and 16 and 15 months (p = 0.261), respectively, for patients with a single brain metastasis. The multivariate analysis showed that HSRT+WBRT was a significant factor only for patients with multiple brain metastases (p = 0.010). The Kaplan-Meier–estimated tumor control rates at 3, 6, 9, and 12 months were 92.2%, 82.7%, 79.5%, and 68.3% in the HSRT+WBRT group and 73.5%, 58.4%, 51.0%, and 43.3% in the HSRT group, respectively, in all 165 patients (p = 0.001). The estimated tumor control rates at 3, 6, 9, and 12 months were 94.3%, 81.9%, 79.6%, and 76.7%, respectively, in the HSRT+WBRT group and 77.8%, 61.4%, 52.6%, and 48.2%, respectively, in the HSRT group in the 80 patients harboring a single metastasis (p = 0.009). The estimated tumor control rates at 3, 6, 9, and 12 months were 90.5%, 83.5%, 79.5%, and 60.9%, respectively, in the HSRT+WBRT group and 68.2%, 54.5%, 48.5%, and 36.4%, respectively, in the HSRT group in the 85 patients with multiple metastases (p = 0.010). The toxicity incidences of Grade 3 or worse were 6.0% (7 of 117 patients) in the HSRT+WBRT group and 1.9% (1 of 54 patients) in the HSRT group (p = 0.438). The differences in neurological death rates between the HSRT+WBRT group and the HSRT group were not statistically significant (34.4% vs 44.7%, p = 0.125, in all patients; 30.0% vs 52.0%, p = 0.114, in patients with a single metastasis; and 38.0% vs 36.4%, p = 0.397, in patients with multiple metastases).
The overall survival results in the present study were similar to those in other studies. Hypofractionated stereotactic radiotherapy provides an alternative method to traditional stereotactic radiosurgery. We suggest that WBRT should be combined with HSRT in patients with single or multiple newly diagnosed brain metastases from NSCLC.