"Hammock" suspending the superior ophthalmic vein: a magnetic resonance imaging study

PURPOSE

The present study aimed to explore the hammock-like structure suspending the superior ophthalmic vein (SOV) using magnetic resonance imaging (MRI).

METHODS

Following conventional MRI examination, 93 outpatients underwent thin-sliced, coronal T2-weighted and contrast imaging of the orbit.

RESULTS

SOVs were consistently detected in all 93 patients. In 90.3% of patients, a hammock-like structure suspending the SOV was identified, which was present on both sides in 64.5% of patients. The structure was frequently located in the anterior and middle thirds of the retrobulbar orbit, suspended from the superolateral corner of the orbital walls. The medial edge of the hammocks did not reach the orbital walls; therefore, they partially encased the SOV. The morphology of the hammock was highly variable between patients, although none were tethered to the extraocular muscles. In addition, a septal band connecting the hammock and optic sheath was identified in 36.6% of patients, most frequently located in the posterior third of the retrobulbar orbit.

CONCLUSIONS

The hammock suspending the SOV and the septal band connecting the hammock and optic sheath may be structures that loosely anchor the SOV to the orbital fat to maintain a constant SOV flow, in addition to preventing excessive bends and obstructions.

Phase II study of S-1 and oxaliplatin as neoadjuvant chemotherapy for locally advanced adenocarcinoma of the gastric or esophagogastric junction: KSCC1601

BACKGROUND

Perioperative chemotherapy is the standard of care for locally advanced gastric cancer (LAGC). This phase II study investigated the efficacy and safety of S-1 and oxaliplatin (SOX) as neoadjuvant chemotherapy (NAC) for LAGC and esophagogastric junction cancer (EGJC).

METHODS

Patients completed up to three cycles of SOX₁₃₀ (oxaliplatin 130 mg/m² on day 1, oral S-1 40-60 mg twice daily for 2 weeks every 3 weeks), followed by gastrectomy and D2 lymphadenectomy. The primary endpoint was the pathological response rate (pRR). The anastomosis leakage rate was the secondary endpoint in patients with EGJC, and other secondary endpoints were the R0 resection, overall survival (OS), and relapse-free survival (RFS) rates.

RESULTS

Between April 2016 and July 2017, 47 patients (24 EGJC, 23 LAGC) were enrolled in this study. Forty-two patients (89.4%, 95% confidence interval [CI] = 76.9-96.5) underwent surgery, and R0 resection was achieved in 41 patients. The pRR was 59.5% (90% CI = 45.7-72.3). The major grade 3 or 4 toxicities were appetite loss in six patients (12.8%), thrombocytopenia in five patients (10.6%), and neutropenia and diarrhea in three patients (6.4%) each. The rate of severe anastomotic leakage (Clavien-Dindo classification grade III or higher) in 20 EGJC was 25.0% (90% CI = 10.4-45.6). The 3-year OS and RFS rate were 62.9% (95% CI = 47.2-75.1) and 53.2% (95% CI = 38.1-66.2), respectively.

CONCLUSION

SOX₁₃₀ demonstrated substantial benefit for LAGC and EGJC. However, special attention should be paid to anastomotic leakage during surgery for EGJC.

Microvascular proliferation in the clots: The key finding of acute subdural hematoma transforming into chronic subdural hematoma?

Background:

Despite extensive investigations, the exact etiology of chronic subdural hematoma (CSDH) remains elusive. Organized CSDHs are a distinct but less-understood type of CSDH.

Case Description:

A 50-year-old hypertensive woman experienced headache without any previous head injury. At presentation, the patient showed no focal neurological deficits. Cranial computed tomography (CT) revealed a slightly compressive subdural hematoma that spontaneously regressed and no intracranial vascular lesions. Cerebral magnetic resonance imaging identified a non-enhancing nodular lesion in the subdural hematoma. After the patient presented disorientation and aphasia on post hospitalization day 14, CT showed a considerable enlargement of the subdural hematoma. Partial removal of the bi-layered hematoma was performed through a parietal craniotomy. Histological examination revealed microvascular proliferation in both the outer membrane and the nodular lesion. On postoperative day 35, CT demonstrated a remarkable resolution of the residual hematoma.

Conclusion:

Development of microvascular proliferation in the clots of an acute subdural hematoma may lead to its rapid enlargement as an organized CSDH. Organized CSDH can be managed by partial removal of the outer membrane and hematoma through a craniotomy.

Late orbital metastasis from colon cancer complicated by multiple tumors in the breast, lung, liver, and spine

A 69-year-old woman sustained progressive proptosis for 2 months. The patient had undergone surgery for resection of colon cancer 10 years prior, which was considered to have been completely cured 5 years prior. She was also aware of a hard mass in her left breast, but it had been left untreated. Furthermore, she experienced back pain for a month. Blood examination revealed an elevated level of serum carcinoembryonic antigen, at 17.4 ng/mL (< 5). Computed tomography (CT) revealed a tumor occupying the superolateral part of the right orbit, with intratumoral calcifications and destructive changes in the lateral orbital wall. On magnetic resonance imaging, it appeared as a heterogeneously enhancing, extraconal tumor, 44 mm × 31 mm in maximal dimension, extending into the middle fossa and the adjacent subcutaneous region. Fluorodeoxyglucose positron emission tomography/CT revealed abnormal accumulation in the left breast, T12 vertebra, liver, and lung, in addition to the orbital tumor. The patient underwent total tumor resection through a lateral orbitotomy. Histological examination of the tumor was highly suggestive of a metastatic colon cancer. Late metastasis should be assumed as a differential diagnosis that can be determined only through histological verification.

Mucoepidermoid carcinoma of the lacrimal gland in a patient with the CRTC1-MAML2 fusion gene

Mucoepidermoid carcinoma (MEC) of the lacrimal gland (LG) is a rare entity. A 47-year-old woman was aware of periorbital swelling for 3 months. At presentation, the patient showed periorbital swelling in the right eye. CT scan showed an isodense mass in the anterior superolateral part of the orbit. MRI delineated the mass as enhancing, extra-conal tumor appearing isointense on T1-weighted sequences, and to be of mixed intensity on T2-weighted sequences. The tumor was totally resected. Microscopically, the tumor tissue was comprised of squamous, epithelioid cells, and cells with plump and clear cytoplasm. Necrosis, neural invasion, or mitotic figures were not observed. Immunohistochemical examination revealed intense staining for cytokeratin 7. A subset of the cells was positively stained with periodic acid-Schiff and mucicarmine stains. Genetic analysis revealed the presence of the CRTC1-MAML2 fusion. The CRTC1-MAML2 fusion may be a useful indicator for the prognosis and planning of adjuvant therapy.

Traumatic cervical vertebral artery aneurysm associated with suicidal stabs

Background

Cervical vertebral artery (VA) aneurysm occasionally develops in association with penetrating injury. However, its treatment strategy is not yet determined.

Case Description

A 50-year-old woman with bipolar disorder attempted suicide by stabbing herself in the lateral neck. At presentation, focal neurological deficits were not observed. Spinal computed tomography (CT) showed unclear delineation of the VA in the right C4/5 intervertebral foramen. CT performed 7 days later identified an aneurysm of the right VA at C4/5, with abnormal arteriovenous shunts between the aneurysm and paravertebral venous plexus. The patient underwent coil embolization of the VA segment involving the aneurysm on the same day that was complicated by cerebellar ataxia due to procedure-associated infarction.

Conclusion

Traumatic VA aneurysms associated with penetrating injuries should be carefully managed with a detailed presurgical evaluation of the relevant cranial and spinal structures.

An unprecedented case of penetrating head trauma caused by shoji (a Japanese-style paper sliding door)

Penetrating head trauma (PHT) includes any traumatic injury where an object pierces the skull and breaches the dural membrane surrounding the brain. PHTs are less prevalent than blunt head injuries. However, they often have more complex damage, worse prognosis, and higher rates of morbidity and mortality. An 83-year-old man fell at his home and hit his head on the right side toward a shoji (a Japanese-style paper sliding door). He reported to the emergency room the following day with his family. He had a small wound before the right ear, which was sutured in the emergency room. A CT scan demonstrated tiny pieces of bone fragments inside the brain, as well as right temporal subcortical hemorrhage and pneumocephalus. He was admitted to the hospital and received intensive prophylaxis with antibiotics. He developed life-threatening skin disease and subsequent acute kidney disease requiring hemodialysis. He fully recovered from his life-threatening condition. Here, we report an unprecedented case of a penetrating head injury of an older adult caused by a shoji.

Emissary Foramina of the External Occipital Protuberance: A Magnetic Resonance Imaging Study

OBJECTIVE

The posterior interparietal region is known to be a distinct area of the skull, predisposing to a variety of bony variants and congenital anomalies. The bony canals in this region have not yet been explored in detail. This study aimed to characterize them.

PATIENTS AND METHODS

Overall, 82 patients underwent thin-slice contrast magnetic resonance imaging. Coronal and sagittal images were used for the analysis.

RESULTS

At the rostral limit of the posterior interparietal region, the parietal foramen (PF) and transmitting emissary vessels were identified in 84% of cases, mostly delineated as single channels. They were located in the left parasagittal region (PS) in 26%, lateral to the left PS in 33%, right PS in 40%, lateral to the right PS in 12%, and midline in 16% of the cases. In 4% of the cases, the PF presented an obstruction around the outer opening. In the more caudal part of the posterior interparietal region, 51% of the patients presented with fine bony canals and transmitting emissary vessels, lying in the midline and parasagittal levels.

CONCLUSIONS

The frequency of PFs may be underestimated for superficially hidden outer openings of the canals. The midline posterior interparietal region may present fine bony canals for transmitting emissary vessels that function complementarily with PFs.

A totally extraperitoneal approach for endoscopic resection of a congenital prepubic sinus through the pubic symphysis

Background

A congenital prepubic sinus (CPS) is a rare congenital anomaly in which a duct remnant extends from the skin opening near the pubic symphysis to various parts and the lesions are mostly located in the preperitoneal space. The totally extraperitoneal (TEP) approach is an operational method that provides a good field of view for the preperitoneal space. We report the CPS through the pubic symphysis in which complete resection was achieved by a TEP approach. TEP approach was minimally invasive and achieved satisfactory cosmetic outcome.

Case presentation

We herein report the case of a 13-year-old boy with a fistula opening near the dorsal penis. He was admitted to our hospital due to fever and lower abdominal pain. Abdominal ultrasonography and computed tomography revealed an abscess inside a fistula lumen on the posterior surface of the rectus abdominis muscles in the midline of the lower abdomen. Under a diagnosis of CPS, which was located in the preperitoneal space, endoscopic resection was performed by a totally extraperitoneal approach. After making an umbilical incision, the rectus abdominis muscle was excised outward to expose the preperitoneal space. A single-port system was placed in the preperitoneal space. Three 5-mm-port trocars were inserted. As the preperitoneal cavity was expanded, a sinus connecting to the pubic symphysis was confirmed. The pubic symphysis did not connect with the bladder. Because the fistula was penetrated with the pubic symphysis, the remaining caudal fistula was removed from the body surface with a small spindle-shaped incision around the fistula opening. Finally, the sinus was completely resected, with confirmation from both the cranial side and dorsal side of the pubic symphysis. We were able to perform complete resection of the CPS with good visibility and without any peritoneal damage. There were no intraoperative complications. His postoperative course was uneventful during the 1-year follow-up.

Conclusions

The TEP approach may be feasible for the resection of a CPS and may allow safe and secure resection due to good visibility, even in pediatric patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40792-021-01245-0.

Massa intermedia of the thalamus: an anatomical study using magnetic resonance imaging

PURPOSE

Few studies have explored the morphology of massa intermedia (MI). The aim of the present study was to characterize it using magnetic resonance imaging (MRI).

METHODS

A total of 205 patients were enrolled in this study. Following initial examinations with conventional MRI sequences, thin-slice coronal and sagittal T2-weighted imaging was performed. For MI localization, the third ventricle was arbitrarily divided into nine areas on the midsagittal image.

RESULTS

MI was identified in 93% of the total patients-89% in male and 91% in female patients. Among them, 68% showed a single, styloid-shaped MI with variable thickness and cross sectional configuration, followed by broad and double MIs that were found in 18% and 10% patients, respectively. In the anteroposterior dimension, 99% of the MIs were identified in the middle third area, followed by the posterior third area. In the supero-inferior dimension, 95% of the MIs were identified in the middle third area, followed by the upper third area. With a significant difference, a broad MI was more frequently found in women than in men.

CONCLUSIONS

MIs are commonly located in the middle third of the third ventricle as a single commissure with high morphological variability. Compared to men, women may have a well-developed, broader MI.

Quadrigeminal cistern arachnoid cyst as a probable cause of hemifacial spasm

Arachnoid cysts arising in the quadrigeminal cistern (ACQCs) are uncommon. A 68-year-old woman presented with an unsteady gait, facial spasm, and cerebellar ataxia. Non-contrast head computed tomography showed a cystic mass centered in the quadrigeminal cistern accompanying ventriculomegaly. On MRI, the cyst appeared hypointense on T1- and hyperintense on T2-weighted sequence. There was no restricted diffusion on diffusion-weighted imaging. The cerebral aqueduct was obstructed and the prepontine cistern was narrowed. The left vertebral artery (VA) coursed adjacent to the facial nerve at its origin. The patient underwent neuroendoscopic fenestration of the posterior wall of the third ventricle and ventral wall of the ACQC. Postoperatively, the patient's symptoms resolved. MRI showed a considerable reduction in the ACQC and expansion of the prepontine cistern, whereas the relationship between the left VA and the proximal segment of the facial nerve did not change. We assumed that the pre-existing close relationship between the VA and facial nerve might have been aggravated by the anterior displacement of the brainstem, thus causing the facial spasm.

Calvarial diploic venous channels: delineation with maximal intensity projection technique

PURPOSE

To date, very few studies have explored the three-dimensional architecture of calvarial diploic venous channels (CDVCs). This study aimed to characterize the three-dimensional architecture of CDVCs using maximum intensity projection (MIP) images based on contrast-enhanced magnetic resonance imaging (MRI).

METHODS

A total of 77 patients with intact calvarial hemispheres and underlying dura mater and dural sinuses underwent contrast-enhanced MRI. Among them, we extracted the data of 49 with at least a part of the major CDVC pathways identified on the MIP images for analysis.

RESULTS

On serial contrast-enhanced MRI images, the CDVCs were commonly detected as curvilinear structures with inhomogeneous diameters and tributaries, while the MIP images delineated the three-dimensional architecture of the developed CDVC pathways. More than such CDVC pathway was entirely delineated on the right in 67.3% and on the left in 71.4%, most frequently in the frontal and temporal regions, with their connecting sites to the sphenoparietal and superior sagittal sinuses. The morphology, distribution, and course of the identified CDVCs were highly variable. In 55.1%, the CDVCs formed fenestrations that were variable in size, shape, and number.

CONCLUSIONS

The developed CDVC pathways may be characterized by morphological variability and fenestrations. Thin-sliced, contrast-enhanced MRI is useful to depict diploic veins, while MIP images allow for better appreciation of the entire course of the developed CDVC pathways. Traumatic and intraoperative disconnection between the dura mater overlying the dural sinuses and the adjacent inner table of the skull can cause epidural venous bleeding.

Arachnoid granulations bulging into the transverse sinus, sigmoid sinus, straight sinus, and confluens sinuum: a magnetic resonance imaging study

PURPOSE

Few studies have explored arachnoid granulations (AGs) bulging into the cranial dural sinuses using contrast-enhanced magnetic resonance imaging (MRI). This study aimed to explore such AGs in the transverse (TS), sigmoid (SigS), and straight (StS) sinuses, and confluens sinuum (ConfS) using thin-sliced, contrast MRI.

METHODS

A total of 102 patients with intact dural sinuses underwent thin-sliced, contrast MRI in the axial, coronal, and sagittal planes.

RESULTS

In 88.2%, more than one AG was identified in the TS and SigS, StS, and ConfS. In the TS, AGs were identified in 40.2% on the right side and 37.3% on the left and were frequently located in the middle and lateral thirds. In the SigS, AGs were identified on the right in 17.6% and on the left in 18.6% in the distal region. In the StS, AGs were identified in 35.3% of cases, most frequently located in the proximal third, followed by the distal third. In the ConfS, AGs were identified in 20.6% of cases. Furthermore, in 23.5%, a collection of multiple AGs of varying sizes was found in the TS. A statistical difference was not shown between the mean age of 90 patients with AGs and that of 12 patients without identifiable AGs.

CONCLUSIONS

Bulging AGs may more frequently found in the TS. Thin-sliced, contrast MRI is useful for delineating AGs.

Dural arteriovenous fistula with crista galli erosion in a patient with suspected sinusitis

Dural arteriovenous fistula (dAVF) of the anterior cranial fossa is an aggressive entity with a high risk of intracranial hemorrhage. A 38-year-old woman presented to our institution with nasal obstruction and discharge. Computed tomography (CT) scans performed for suspected sinusitis revealed erosion of the crista galli predominantly on the left side. The frontal and ethmoidal sinuses adjacent to the crista galli were clear and did not communicate with the crista galli. Contrast computed tomography scans revealed ectatic vessels adjacent to the crista galli, coursing on the cortical surface. Cerebral angiography identified an anterior fossa dAVF supplied by the bilateral anterior and posterior ethmoidal arteries and drained by the dilated cortical veins. Based on these findings, we assumed that long-term compression by the pulsatile draining veins caused the erosion. The patient underwent successful microsurgical disconnection procedure of the dAVF with an uneventful postoperative course. We concluded that external erosion of the crista galli could be a sign of aggressive dAVF and requires careful examination.

Hyperintense areas in the intraorbital optic nerve evaluated by T2-weighted magnetic resonance imaging: a glymphatic pathway?

PURPOSE

The present study aimed to explore the glymphatic pathway in the intraorbital optic nerve (ON) using magnetic resonance imaging (MRI).

METHODS

Following conventional MRI examination, a total of 89 outpatients underwent T2-weighted imaging in thin-sliced coronal and sagittal sections. Moreover, three injected cadaver heads were dissected.

RESULTS

In the cadaver specimens, differences in appearance between the central and peripheral parts of the ON were not observed. On the axial T2-weighted MRI performed in the initial examination, the central part of the intraorbital ONs was delineated as a well-demarcated, linear hyperintense area in 19% of patients. On the thin-sliced serial coronal images, the hyperintense areas were identified on both sides in 91% of patients. They were delineated as continuous hyperintense areas in the ONs with an inconsistent appearance even in the same nerve. In 12.4% of patients, the areas were divided into the upper and lower parts by a horizontal septum, while others showed variable morphologies, lacking a septum. On thin-sliced sagittal images, hyperintense areas were identified in 46% of patients.

CONCLUSION

Hyperintense areas in the intraorbital ON detected on T2-weighted sequences may involve a glymphatic pathway with perivascular spaces of the ON and central retinal artery. These may be collapsed and difficult to identify on surgical and cadaver specimens.

Subependymal hyperintense layer on CISS sequence: An MRI study

PURPOSE

The present study aimed to explore the subependymal layers overlying the cerebral ventricles using magnetic resonance imaging.

METHODS

A total of 69 outpatients underwent constructive interference in steady-state (CISS) sequence in thin-sliced, coronal, and sagittal sections.

RESULTS

The subependymal layers were delineated as linear hyperintensities, coursing along the outer margins of the ventricular walls. On coronal images, the hyperintensities surrounding the anterior horn of the lateral ventricle were identified in 97% of patients, while those of the third ventricle were identified in 96% of patients. In the trigone and posterior horn of the lateral ventricle, the hyperintensities were delineated in all patients. On sagittal images, subependymal hyperintensities were identified in all. At the level of the anterior horn and third ventricle, the subependymal hyperintensities were found to communicate with the Virchow-Robin spaces (VRSs) in 68% and 65% of patients, respectively. At the level of the trigone and posterior horn of the lateral ventricle, the VRSs communicated with the subependymal hyperintensities in 83% of patients.

CONCLUSIONS

Subependymal hyperintensity may represent an inflow passage of the VRSs that jointly contribute to efficient transependymal migration of the interstitial fluid into the ventricular cerebrospinal fluid.

Trochlear cistern of the cavernous sinus: an anatomical study using magnetic resonance imaging

PURPOSE

The present study aimed to explore the trochlear cistern (TC) of the cavernous sinus using magnetic resonance imaging (MRI).

METHODS

Following conventional MRI examination, a total of 73 patients underwent the constructive interference steady-state (CISS) sequence in thin-sliced coronal sections. Moreover, three injected cadaver heads were dissected.

RESULTS

In the cadaver specimens, the extent of the TC was difficult to identify on any dissected side. On the CISS images, the TC was identified in 98.6% on the right side and 94.5% on the left, while transmitting the trochlear nerve (TN) was identified in 83.6% on the right and 79.5% on the left. Most TNs were delineated as a single trunk, while duplication of the nerve was found in 3% of cases. The TC, commonly located inferior or inferolateral aspect of the oculomotor trigone. The size and extent of TC were highly variable. The TN location in the TC was also variable and was identified throughout the upper, middle, and lower parts of the TC. Moreover, relationships between the TC and Meckel's cave were highly variable.

CONCLUSIONS

TC shows morphological variability. The coronal CISS sequence is useful for exploring TC and TN in clinical practices.

Traumatic acute epidural hematoma caused by injury of the diploic channels

Background

Traumatic acute epidural hematomas (EDHs) commonly develop by rupture of the meningeal arteries. EDH caused by an injury of the diploic channel (DC) has not been reported.

Case Description

A 21-year-old man suffered a head injury while falling off the skateboard. At presentation, the patient was drowsy but did not exhibit any focal neurological deficits. Cranial computed tomography (CT) revealed a biconvex intracranial hematoma with 18-mm thickness in the high parietal region and a linear fracture that involved both the outer and inner tables and passed above the hematoma. A well-developed and large DC was observed near the hematoma. Patient's consciousness level decreased at 12 h after admission with considerable growth of the hematoma. A frontoparietal craniotomy revealed an EDH. The dura mater and the meningeal arteries underneath the hematoma were intact. The medial bone cut caused brisk bleeds from the large DC. Postoperative CT revealed the cut of the DC and other finer DCs exhibiting air density and lying near the fracture. Based on these findings, we assumed that the EDH was developed by an injury of the DCs.

Conclusion

Traumatic EDH can develop by an injury of the DCs. Careful observation of patient's neurological status and precise interpretation of neuroimages is important to identify venous EDHs.

Familial cerebral cavernous malformation presenting with epilepsy caused by mutation in the CCM2 gene: A case report

RATIONALE

Cerebral cavernous malformation (CCM) of the familial type is caused by abnormalities in the CCM1, CCM2, and CCM3 genes. These 3 proteins forming a complex associate with the maintenance of vascular endothelial cell-cell junctions. Dysfunction of these proteins results in the development of hemangiomas and abnormal intercellular junctions.

PATIENT CONCERNS

We report a 68-year-old man with familial cerebral cavernous malformation with initial presentation as convulsions at an advanced age. Brain magnetic resonance imaging revealed multiple cavernous hemangiomas in the right occipital lobe. The convulsions were considered to be induced by hemorrhage from cavernous hemangioma in the right occipital lobe.

DIAGNOSES

Genetic screening of the CCM1, CCM2, and CCM3 genes revealed a novel mutation in the CCM2 gene (exon4 c: 359 T>A, p: V120D). No abnormalities were found in CCM1 or CCM3. Therefore, we diagnosed the patient with familial CCM caused by a CCM2 mutation.

INTERVENTIONS

This patient was treated with the administration of levetiracetam at a dosage of 1000 mg/day.

OUTCOMES

No seizures have been observed since the antiepileptic drug was administered. We performed brain magnetic resonance imaging (MRI) regularly to follow-up on appearance of new cerebral hemorrhages and cavernous hemangiomas.

LESSONS

This report reviews cases of familial cerebral cavernous malformations caused by abnormalities in the CCM2 gene. This mutation site mediates interactions with CCM1 and CCM3. The mutation occurs in the phosphotyrosine binding (PTB) site, which is considered functionally important to CCM2.

Spinal endodermal cyst undergoing malignant transformation and marked elevation of serum carbohydrate 19-9 level

Endodermal cyst (EC) is a benign tumor that can arise along the craniospinal axis. Infrequently, ECs undergo malignant transformation. A 43-year-old man presented with numbness in the right arm, leg and occipitalgia. MRI revealed a multicystic, intradural extramedullary tumor at C2 with enhancement along the ventral surface of the spinal cord. Blood test showed an abnormal increase in serum carbohydrate antigen 19-9 (CA 19-9) level. Systemic positron emission tomography-computed tomography was normal. He underwent total tumor resection and was diagnosed with EC. He developed double vision, hearing loss, and swallowing difficulty on postoperative day 70. Cerebral MRI revealed marked extensions of leptomeningeal dissemination. The serum CA 19-9 level increased continuously and finally reached 1515.0 U/ml. He died of respiratory failure on day 108. An autopsy did not reveal abnormalities in the abdominal and chest organs. On microscopic examination, the post-mortem specimen revealed adenocarcinoma. Immunohistochemically, both the surgical and autopsy specimens were positive for CA 19-9. Spinal ECs may lead to malignant transformation with leptomeningeal dissemination that causes abnormal elevation of serum CA 19-9 levels.

Endovascular Therapy for Aneurysmal Subarachnoid Hemorrhage Complicated by Neurogenic Pulmonary Edema and Takotsubo-Like Cardiomyopathy: A Report of Ten Cases

Objective:

Patients sustaining aneurysmal subarachnoid hemorrhage (aSAH) can be further complicated by neurogenic pulmonary edema (NPE) and Takotsubo-like cardiomyopathy (TCM) with dismal outcomes. The present study aimed to validate the efficacy of endovascular therapy for patients with aSAH complicated by NPE and TCM.

Materials and Methods:

Patients who were diagnosed with aSAH complicated by NPE and TCM and treated by endovascular therapy were retrospectively evaluated.

Results:

In the past 5 years, a total of ten female patients with aSAH were also diagnosed with NPE and TCM. Six of the ten were cases with high-grade aSAH (Hunt and Hess Grades IV and V), whereas four were low-grade aSAH (Grades II and III). The locations of ruptured aneurysms were the internal carotid-posterior communicating artery junctional site in five patients, the anterior communicating artery in two, the vertebral artery in two, and the middle cerebral artery in one. These aneurysms were successfully embolized by endovascular therapy without any procedure-associated complications. The clinical outcome measure at 6 months after discharge on the Modified Rankin Scale was found to be 0 in four patients, 1 in two, 3 in one, and 5 in three.

Conclusions:

Endovascular therapy can be a feasible, alternative measure for the treatment of patients with high-grade aSAH who also have NPE and TCM.

Intermittent oculomotor nerve paresis and hollow appearance on MRI manifested by pituitary adenoma

A 71-year-old man had sustained intermittent ptosis and double vision for 2 weeks. Neurological examination found unilateral oculomotor nerve (CN III) paresis manifesting as limitations of gaze, ptosis, and mydriasis. Neither headache nor any other cranial neuropathy was noted. Cerebral magnetic resonance imaging revealed a well-circumscribed mass in the pituitary fossa extending laterally into the left cavernous sinus. The segment of the left CN III lying in the oculomotor cistern was considerably compressed by the tumor. The cisternal segments of the left CN III showed an undescribed, “hollow” appearance. The left orbit and brainstem were intact. The patient underwent tumor resection via an endoscopic transsphenoidal approach. The tumor tissue was soft in consistency, involving xanthochromic fluid. The pathological diagnosis was pituitary adenoma accompanied with considerable hemorrhagic changes. The patent's ptosis and limitations of gaze showed remarkable improvements on postoperative day 1, with resolution of the hollow appearance of the affected CN III that was confirmed on day 3. We assumed that the intralesional bleeds and lateral tumor extension into the oculomotor cistern were associated with the intermittent paresis of the CN III as the sole presentation. A hollow appearance identified in the CN III might indicate a reversible dysfunction of the nerve that can anticipate an improvement by prompt surgical intervention.

Possible cerebrospinal fluid pathways in the middle fossa floor and pterional diploe: a magnetic resonance imaging study

PURPOSE

There has not been a study documenting the distribution of cerebrospinal fluid (CSF) pathways in the anterolateral base of the middle fossa (ALB) and diploe of the pterional region (Pt). The present study aimed to delineate these pathways using magnetic resonance imaging.

METHODS

Thin-sliced, axial, and coronal T2-weighted sequences were performed for a total of 358 outpatients, including 20 pediatric patients.

RESULTS

Adult population: CSF-filled channels were identified on axial images in the ALB in 57% and in the diploe of the Pt in 65% of 338 patients. These pathways showed variable morphology and number bilaterally. CSF-filled channels were identified on coronal images in the ALB in 14% and in the diploe of the Pt in 100% of 59 patients. These were delineated as linear structures of variable number and thickness. Eleven percent of the pathways identified in the ALB was connected with extracranial channels. Pediatric population: CSF-filled channels were identified on axial images in the ALB in 75% and in the diploe of the Pt in 80% of 20 patients.

CONCLUSIONS

The ALB and diploe of the Pt may function as CSF pathways in children and adults. The pathways in the ALB can be a CSF-drainage route connecting to the extracranial sites.

Diploic veins of the cranial base: an anatomical study using magnetic resonance imaging

PURPOSE

The anatomy and distribution of the diploic veins (DVs) of the cranial base have not been fully documented. The aim of this study was to characterize these veins using contrast magnetic resonance imaging (MRI).

METHODS

In total, 95 patients underwent thin-sliced, contrast MRI. Coronal and sagittal images were used for the analysis. The cranial base was divided into the anterior, middle, and posterior bases. Then, each base was further subdivided into three equal parts in the anteroposterior and lateromedial directions. The anteroposterior parts were evaluated on coronal images, while the lateromedial parts were evaluated on sagittal images.

RESULTS

The DVs were identified over the entire cranial base. However, they were more frequent in the posterior-third of the lateral-third region of the anterior, middle-third of the lateral and middle-third regions of the middle, and middle-third region of the posterior cranial base, and sparse in the posterior and medial-third regions of the middle cranial base. The DVs showed marked morphological variability. For instance, the DVs of the pterional area were generally well defined, as pivotal channels connecting the lateral parts of the anterior and middle cranial base, but were highly varied in appearance.

CONCLUSIONS

The DVs of the cranial base are distinct structures characterized by morphological variability and topographical predilection. Contrast MRI is useful for delineating these veins.

Vertebral artery segment at the suboccipital dural penetration site: an anatomical study using magnetic resonance imaging

PURPOSE

The morphology of the vertebral artery (VA) segment at the suboccipital dural penetration site has little been explored with magnetic resonance imaging (MRI). Therefore, the aim of this study was to examine the structure using MRI.

METHODS

In total, 94 patients underwent thin-sliced, contrast MRI in the axial, coronal, and sagittal planes involving the atlas, axis, occipital bone, and V3 and V4 segments of the VA.

RESULTS

The VA segment at the suboccipital dural penetration site was well-delineated in 93% on the axial images and in 95% on the coronal images. The axial images showed that 82% of the VA penetration sites were located in the middle third of the dural sac. Meanwhile, the coronal images revealed that the heights of both VA penetration sites were located at the same level in 87%. The axial VA penetration angle, which is formed by the VA and tangential line of the dural sac, was 66 ± 11.9° on the right side and 61 ± 14.1° on the left side. The coronal VA penetration angle, which is formed by the tangential line of the VA and dural sac, was 111 ± 24.6° on the right side and 112 ± 19.9° on the left side.

CONCLUSIONS

The morphology of the VA segment is considerably variable at the suboccipital dural penetration site, while most penetration sites are located in the middle third of the dural sac on axial MRI. These should be assumed during surgeries around the suboccipital VA penetration site.

Atypical spinal endodermal cyst presenting with contralateral C2 neuralgia and aseptic meningitis

A previously healthy 43-year-old man presented with durable occipitalgia for 1 month. Neurological examination revealed severe pain in the right C2 area accompanied by neck stiffness. Magnetic resonance imaging revealed an enhancing, polycystic intradural mass at the C2 level, occupying the left dorsolateral part of the spinal canal. In addition, a rim-like enhancement was found along the surfaces of the spinal cord. Blood tests did not show signs of infection. A lumbar spinal tap revealed albuminocytologic dissociation without cultured organisms. Cranial computed tomography scans taken 20 days later revealed an overt ventriculomegaly. The patient underwent a total tumor resection through hemilaminectomy of the C2. Intraoperatively, the left dorsal C2 roots were found to be extremely redundant due to the tumor and surrounding thickened arachnoids. The roots restored normal morphologies after resection of the arachnoids and tumor. Postoperatively, the patient's symptoms resolved and histological diagnosis was endodermal cyst. Four weeks later, a ventriculoperitoneal shunt was placed to treat progressive ventriculomegaly. A polycystic intradural mass of the upper cervical spine should assume an endodermal cyst that may cause contralateral occipitalgia and aseptic meningitis.

Interdural high signal on CISS sequence: an alternative CSF pathway?

PURPOSE

The falx cerebri, falx cerebelli, and tentorial notch exhibit a peculiar morphology with a two-layered, dural leaf that protrudes into the cranial cavity with a free edge. However, there are few studies exploring this morphology using neuroimaging techniques. The present study aimed to explore these dural structures using magnetic resonance imaging.

METHODS

A total of 65 outpatients were included in this study. Following initial examinations with conventional sequences, the constructive interference in steady-state (CISS) sequences were performed in thin-sliced, coronal sections.

RESULTS

In 78% of the subjects, the interdural spaces presenting with high signal were identified in the falx cerebri. These spaces were located adjacent to the uppermost part of the falx, formed by two dural leaves and the superior sagittal sinus, and tapered downward where the leaves united to form the falx cerebri. At the tentorial notch, these spaces were found in 52% of the 65, most predominantly in the medial edge followed by the tentorium cerebelli-tentorial notch junctional region. Forty-one percent of patients had a dural opening into the cerebral cistern. The interdural spaces with high signal were not identified in the tentorium cerebelli in any of the subjects.

CONCLUSIONS

The falx cerebri and tentorial notch form the interdural spaces that may provide alternative cerebrospinal fluid pathways. The coronal CISS sequence is suitable for delineating such interdural spaces.

Visualization of the vidian canal and nerve using magnetic resonance imaging

BACKGROUND AND PURPOSE

Few studies have investigated the vidian nerve (VN) and vidian canal (VC) with the use of magnetic resonance imaging (MRI). The present study aimed to characterize the VC and VN using MRI.

MATERIALS AND METHODS

A total of 91 patients underwent thin-sliced, contrast MRI. The course of the VC and VN and the relationships with relevant structures were analyzed.

RESULTS

The VC was identified in 95% of axial images on the right side and in 93% on the left. The course of the VC was delineated in 99% of serial coronal images on both sides. The VN location in the VC was highly variable. The course of the VC and transmitting VN was delineated in 95% of sagittal images on the right side and in 91% on the left. The mean length of the VC was 19.8 mm on the right side and 19.3 mm on the left. Topographical relationships between the anterior genu of the petrous internal carotid artery and the posterior end of the vidian canal could be classified into three types. Of these, the type terminating at the level of the petrous carotid was the most predominant, comprising 76% of 182 sides. The course of the VC and transmitting VN could be classified into four types. The straight type was the most predominant and was found in 41%.

CONCLUSIONS

The VC and transmitting VN are structures with variable morphologies. Contrast MRI is useful for delineating the VC and VN.

Atypical epidural hemangiopericytoma presenting with visual disturbance

Background:

Hemangiopericytomas are a rare entity commonly presenting as subdural tumors.

Case Description:

A 57-year-old man presented with a progressive visual disturbance over a period of 3 weeks. Cranial computed tomography scans revealed an isodense mass at the tip of the left middle fossa, extending into the orbital apex, and accompanying bony erosions in the sphenoid ridge. On magnetic resonance imaging, the lesion appeared isointense both on T1- and T2-weighted sequences, and intensely enhanced on contrast examinations. A frontotemporal craniotomy revealed a dura-based, capsulized tumor located entirely in the epidural space. A gross total resection was achieved for the tumor and histologically verified as hemangiopericytoma.

Conclusion:

Hemangiopericytoma should be assumed in a differential diagnosis when encountering epidural tumors, and total resection should be attempted when possible.

Spinal Dural Arteriovenous Fistula Assumed to be Symptomatic after Placement of Lumbar Cerebrospinal Fluid Drain

A 69-year-old man presented with severe headache. Cranial computed tomography revealed diffuse subarachnoid hemorrhage. An anterior communicating artery aneurysm was identified and successfully obliterated by open microsurgery on the same day. Following placement of a continuous lumbar cerebrospinal fluid drain on hospitalization day 7, the patient developed a severe paraplegia and sensory loss below T6. Cerebral magnetic resonance imaging did not identify a responsible lesion. Spinal magnetic resonance imaging, however, showed extensive intramedullary hyperintensity on T2-weighted sequences. Spinal angiography identified a dural arteriovenous fistula fed by the segmental artery branching with the 12th intercostal artery. It was successfully embolized and the patient's sensorimotor disturbances remarkably improved. A spinal dural arteriovenous fistula may better be considered as one of the underlying etiologies when patients exhibit new neurological deficits after placement of a continuous lumbar cerebrospinal fluid drain.

Communicating hydrocephalus and coexisting nonenhancing tumor: An ominous sign for patients with neurofibromatosis type 1?

A 26-year-old woman with familial neurofibromatosis type 1 sustained headache that worsened for 1 month. Neuroimaging revealed a mild ventriculomegaly and nonenhancing lesion in the pons. In spite of repeated cerebrospinal fluid examinations and magnetic resonance imaging, the etiology was not determined. The affected pons markedly enlarged in the following 2 months, with extensive leptomeningeal dissemination. Biopsy through hemilaminectomy of the T9 was diagnosed as glioblastoma multiforme. Prompt histologic examination should be performed when patients with familial neurofibromatosis type 1 manifest communicating hydrocephalus coexistent with a nonenhancing tumor.

Cerebrospinal fluid spaces between intracranial venous sinuses and overlying dura mater: magnetic resonance imaging

Purpose The intracranial venous sinuses are thought to lie interdurally, circumferentially contacting the dura maters. There has been no report documenting the cerebrospinal fluid spaces intervening between the venous sinuses and overlying dura mater. Here, we explored such structures using magnetic resonance imaging. Methods A total of 206 patients underwent magnetic resonance imaging with a T2-weighted or constructive interference steady-state sequence. Imaging data were analysed on a workstation. Results The peri-superior sagittal sinus cerebrospinal fluid spaces were identified in 100% of 133 patients who underwent coronal and sagittal T2-weighted imaging and in 98.6% of 73 with a constructive interference steady-state sequence. Among the 205 patients, the cerebrospinal fluid spaces were distributed over the frontoparietal region in 84% and the parietal region in 16%. On sagittal sections performed for 58 patients, the cerebrospinal fluid spaces were identified between the superior sagittal sinus and overlying dura mater. The peri-sinus spaces were found in 91% of the identified transverse sinuses, 29% of the straight and 70% of the occipital sinuses. The peri-superior sagittal sinus cerebrospinal fluid spaces were classified into five distinct appearances. The circumferential type was the most predominant and was found in 68.7%, followed by lateral in 10.2%, lateral plus inferior in 7.5%, lateral plus superior in 6.8% and superior in 6.8%. Conclusions The intracranial venous sinuses do not circumferentially contact with the dura maters. Instead, they are adjacent to the cerebrospinal fluid spaces intervening between the walls and overlying dura maters. These spaces are critical when considering tumour extensions contralateral to the superior sagittal sinus and safe surgical manoeuvres around it.

Large presacral epidermoid cyst in an asymptomatic woman

An epidermoid cyst is an infrequent entity among cysts found in the presacral region, frequently coexistent with a meningocele. Diffusion-weighted imaging is known to be a useful diagnostic measure for differentiating presacral epidermoid cysts. Here, we present a large but asymptomatic case found in the presacral region. Epidermoid cysts should be considered in patients with presacral cysts.

Posterior Fossa Arteriovenous Malformation with Multiple Pedicle Aneurysms and Recruitment of Meningeal Supply

Cerebral aneurysms arising on the peripheral posterior inferior cerebellar artery (PICA) are rare. Here, we present a unique case of arteriovenous malformation (AVM) with pedicle aneurysms arising on the peripheral PICA and recruited by meningeal supply. A 67-year-old woman presented with subarachnoid hemorrhage. Cerebral angiography revealed two saccular aneurysms on the peripheral PICA, which formed an abnormal arteriovenous shunt adjacent to the transverse sinus. The shunt was also fed by the ipsilateral superior cerebellar and contralateral posterior meningeal arteries. The proximal aneurysm was larger and deep seated while the distal aneurysm was smaller and located superficially. The patient underwent coil embolization of the proximal aneurysm followed by microsurgical trap of the distal aneurysm and resection of the arteriovenous shunt lying superficially in the cerebellar hemisphere. The shunt was histologically verified as AVM. Staged approach with coil embolization and open microsurgery can be a treatment option for multiple PICA aneurysms associated with an AVM.

The cisternal segment of the anterior choroidal artery: an anatomical study using magnetic resonance imaging

PURPOSE

The topography of the anterior choroidal artery (AChA) has infrequently been delineated on neuroimages. The present study aimed to explore the cisternal segment of the AChA using magnetic resonance imaging.

METHODS

A total of 50 sides of the AChA obtained from 25 patients were included in this study. A constructive interference in steady-state (CISS) sequence was performed in thin-sliced axial sections. Furthermore, the cisternal AChA and relevant neurovascular structures were observed through cadaveric dissections in two heads.

RESULTS

In the cadaveric dissections, all the AChAs were exposed only in the proximal part even after extensive arachnoid dissections and cerebral retraction. In the examinations with the CISS sequence, the original site of the AChA was identified on the right side in 88% and on the left side in 96%. In 70% of the 50 sides, the AChA arose from the posterolateral wall of the internal carotid artery, distally to that of the posterior communicating artery. The cisternal course of the AChA was delineated on the right side in 96% and on the left side in 100%; it crossed over the optic tract in variable manners with the middle third as the most frequent site found in 60% of the sides.

CONCLUSIONS

The cisternal AChA shows a morphological variability. The CISS sequence is useful for delineating the cisternal AChA.

Role of cathepsin K in the development of chronic subdural hematoma

Despite extensive investigations, the process of development of chronic subdural hematoma (CSDH) is not known. The present study aims to investigate CSDH by measuring biomarkers in it, gas analysis, and immunohistochemical examination. A total of 42 patients with symptomatic CSDH who underwent burr-hole drainage were enrolled. Intraoperatively, hematoma fluid and peripheral venous blood (PV_CSDH) were simultaneously collected. As controls, peripheral venous blood (PV_Control) and intracranial cerebrospinal fluid (CSF) were collected from other subjects during other surgeries. CatK, lipocalin-type prostaglandin D synthase (PGDS), and cystatin C (CysC) present in these specimens were measured using enzyme-linked immunosorbent assay. Data obtained were statistically analyzed after age correction. In 15 patients, gas analysis was performed for CSDH and PV_CSDH. Furthermore, immunohistochemical examination for the outer membrane was performed for four patients. CatK, PGDS, and CysC levels were markedly elevated in the CSF and CSDH. CatK levels in PV_CSDH were significantly higher than in PV_Control (P<0.0001). In contrast, CysC levels in PV_CSDH were significantly lower than in PV_Control (P=0.004). The gas analysis revealed that the internal environment of CSDH is characterized by marked hypoxia, hypoglycemia, and lactic acidosis. Furthermore, the outer membrane consistently showed a diffuse staining for CatK. Based on these, CatK was thought to play a role in the development of CSDH, with the levels in peripheral venous blood elevated in patients with CSDH.

Visualization of cerebrospinal fluid-filled spaces in the cavernous sinus using magnetic resonance imaging

The cavernous sinus (CS) has been extensively studied and is commonly acknowledged as a dural venous sinus. There have been no reports documenting cerebrospinal fluid (CSF)-filled spaces in the CS. Here, we explore such structures in the CS using magnetic resonance imaging (MRI). A total of 183 patients underwent T2-weighted or constructive interference steady-state (CISS) sequence MRI. Imaging data from coronal sections were analyzed. Of the 183 patients, 26.8% had CSF-filled spaces in the CS. These spaces appeared to communicate with the suprasellar cistern through dural defects found in the superior wall of the CS, and also appeared to surround the cavernous portion of the internal carotid artery (ICc) and pituitary gland, and further be adjacent to the oculomotor and trigeminal cisterns. Dural defects were identified in 81.6% of patients, with CSF-filled spaces adjacent to the oculomotor and trigeminal cisterns found in 81.6% and 12.2% of patients, respectively. The distribution of these spaces could be classified into four types based on their topographical relationships with the ICc, namely the circumferential, medial, lateral, and superior types. The circumferential and medial types were the most frequently found and comprised >80% on both sides. The CS may involve CSF-filled spaces in physiological conditions that are formed through dural defects in the superior wall and adjacent cranial nerve cisterns. These findings are critical when considering approaches to the CS, modes of lateral extension of pituitary tumors, and CSF dynamics in the CS.

Cortical bridging venous segment protruding into the inner skull depression: a potential site of hemorrhage at external ventriculostomy

PURPOSE

The cortical bridging venous segment protruding into the inner skull depression (CBVISD), a distinctive structure found in the calvarial convexity, may be a potential risk factor for hemorrhagic complications resulting from trephination. However, this subject has not been documented. In the present study, we explore the CBVISD using magnetic resonance imaging (MRI).

METHODS

A total of 94 patients underwent contrast-enhanced MRI. Distributions of the CBVISDs were recorded in two symmetrical regions of the frontal calvarial convexity. The lateral dimensions on both hemispheres were defined to range between 25 and 35 mm from the midsagittal section. The anteroposterior axis was delimited anteriorly by the supraorbital bar and posteriorly by the coronal suture, which was further divided into four parts: the forehead (FH), anterior frontal (AF), FH-AF junctional, and posterior frontal (PF) regions.

RESULTS

Analysis of the delineations revealed that the CBVISDs had variable shapes and sizes. They were identified on the right side in 40% of the 94 patients and in 41% on the left side. Among the 91 identified CBVISDs, 5.5% of the CBVISDs were located in the FH, 17.6% in the FH-AF, 34.1% in the AF, and 42.9% in the PF.

CONCLUSIONS

The CBVISDs are most frequently located at the common trephination site of external ventriculostomy. Trephination performed in the FH and FH-AF junctional regions may be safer than that in more posterior frontal areas.

Vascular Compression of the Anterior Optic Pathway: A Rare Occurrence?

BACKGROUND

Vascular compression of the anterior optic pathway has been documented as an infrequent cause of visual impairments. Here we characterize such vascular compression using magnetic resonance imaging.

METHODS

A total of 183 patients without pathologies affecting the optic pathways underwent T2-weighted or constructive interference steady-state sequence magnetic resonance imaging. Imaging data from coronal sections were analyzed.

RESULTS

A vascular compression of the anterior optic pathway was identified in 20 patients (11%). They comprised 13 men and 7 women with a mean age of 60.8 years. The vascular compressions were observed at 22 sites, 15 on the optic nerve (ON) and 7 on the optic chiasm (OC). Twelve of them were on the right and 10 were on the left side. The offending vessels were the supraclinoid portion of the internal carotid artery in 86.4% and the A1 segment of the anterior cerebral artery in 13.6%. Compression sites at the ON and OC were variable, with the inferolateral surface being the most frequent (77.3% occurrences). In 2 patients (9.1%), the ON was compressed in a sandwich manner.

CONCLUSIONS

Vascular compression of the ON and OC may not be an infrequent occurrence in the cranial cavity. Progressive and unexplainable visual impairment might possibly be caused by vascular-compressive neuropathy.

Preservation of Rat Aortic Tissue Transplant with Green Tea Polyphenols

Green tea polyphenols have recently attracted medical attention as bioactive agents with anticancer, antimicrobial, and antiviral effects. We discovered their new usage as preservative agents for tissue transplants. We preserved rat aortas in a DMEM solution containing polyphenols extracted from green tea leaves. The preserved aortas retained original structures and mechanical strength, and were devoid of any undesirable cell secretions for over a month under physiological conditions. In addition, aortas from Lewis rats preserved for a month and transplanted to allogenic ACI rats completely avoided rejection by the host, suggesting that the polyphenols have immunosuppressive actions on the aortic tissues. From these results, we conclude that polyphenol treatment of aortic tissue transplant can maintain its viability for extended periods of time either before or after transplantation, and the method can be applicable to other transplantation situations.

Programmed death-ligand 1 expression at tumor invasive front is associated with epithelial-mesenchymal transition and poor prognosis in esophageal squamous cell carcinoma

Programmed death‐ligand 1 (PD‐L1) plays a crucial role in the host immune system in cancer progression. The gene promoter region of PD‐L1 also contains a binding site for ZEB1, a transcription factor related to epithelial‐mesenchymal transition (EMT). The purpose of this study was to clarify the relationship between PD‐L1 and EMT and its clinical importance in esophageal squamous cell carcinoma (ESCC). PD‐L1 and ZEB1 expression at the tumor invasive front was examined by immunohistochemistry in resected specimens from 90 patients with ESCC who underwent surgery without preoperative therapy, and their expression and clinicopathological factors were compared. ZEB1 and PD‐L1 expression was determined in TE8 cells, which demonstrate the EMT phenotype, following ZEB1 knockdown by siZEB1. TE5, TE6 and TE11 cells with non‐EMT phenotype were also used for studies of TGF‐β1‐dependent EMT induction and ZEB1 and PD‐L1 expression. In cases of high PD‐L1 expression at the invasive front, significantly greater depth of tumor invasion, EMT, and less CD8⁺ lymphocyte infiltration were observed. High PD‐L1 expression was also associated with worse overall and relapse‐free survival. A correlation was observed between PD‐L1 and ZEB1 expression. In TE8 cells, siZEB1 suppressed PD‐L1 and promoted E‐cadherin mRNA and protein expression. TGF‐β1 induced EMT and surface expression of PD‐L1 in TE5, TE6 and TE11 cell lines. PD‐L1 expression at the ESCC invasive front was related to ZEB1 expression, EMT and poor prognosis. We suggest that a cooperative mechanism bridging between tumor immune avoidance and EMT contributes to tumor malignancy in ESCC.

Association of epithelial-mesenchymal transition with an immunosuppressive tumor microenvironment with elevated levels of PD-L1 in esophageal carcinoma

e15585

Background: Programmed death-ligand 1 (PD-L1) plays a crucial role in the host immune system in cancer progression and is has become a new target for cancer therapy. PD-L1 gene promoter region contains a binding site of ZEB1, a transcription factor related to epithelial-mesenchymal transition (EMT). The purpose of this study is to clarify relationships between PD-L1, EMT and its clinical importance in esophageal squamous cell carcinoma (ESCC). Methods: We conducted preclinical studies using cell lines and clinical specimens. ZEB1, PD-L1 expression in TE8 cell line, demonstrating EMT phenotype, was determined following ZEB1 knockdown by siZEB1. TE5, 6 and 11 cell lines with non-EMT phenotype were also used for studies of TGF-β1-dependent EMT induction and ZEB1, PD-L1 expression. PD-L1 and ZEB1 expression at the tumor invasive front was examined in resected specimens from 90 patients with ESCC who underwent surgery without preoperative therapy by immunohistochemistry and their expression and clinicopathological factors were compared. Results: A correlation was observed between PD-L1 and ZEB1 expression. In TE8 cells which express EMT character , siZEB1 suppressed PD-L1 and promoted E-cadherin mRNA and protein expression. In TE5, 6 and 11 cell lines which are not EMT phenotype, TGF-β1 induced EMT and surface expression of PD-L1. In cases of high PD-L1 expression at invasive front, greater depth of tumor invasion, EMT, less CD8 expression were significantly observed. High PD-L1 expression was also associated with worse overall and relapse-free survival. Conclusions: PD-L1 expression at the invasive front was related to ZEB1 expression, EMT and poor prognosis in ESCC. We suggest that cooperative mechanism between tumor immune avoidance and EMT contributes to tumor malignancy. Whether or not ZEB1-PD-L1 signal pathway could be a target in treatment for ESCC requires further investigations.

Clinical Significance of Totally Laparoscopic Distal Gastrectomy: A Comparison of Short-term Outcomes Relative to Open and Laparoscopic-assisted Distal Gastrectomy

BACKGROUND

Laparoscopic distal gastrectomy has become an established minimally invasive treatment for gastric cancer since it was first reported in 1994.

MATERIALS AND METHODS

We retrospectively assessed the clinical outcomes of 248 patients who had undergone open distal gastrectomy (ODG), laparoscopic-assisted distal gastrectomy (LADG), and totally laparoscopic distal gastrectomy (TLDG) for gastric cancer.

RESULTS AND CONCLUSIONS

TLDG showed superiority in terms of blood loss, reconstruction options, and postoperative recovery compared with ODG and LADG. Especially, the mean operating time in the TLDG group was significantly shorter than that of the LADG group (P=0.003). Book-binding technique used in TLDG was one of the reasons of this result. The only inferior aspect of TLDG was the longer operating time compared with ODG; TLDG had no disadvantages compared with LADG. Although the operating time and long-term outcome remain problems, we suggest that TLDG has the potential to serve as an optimal operative method.

Immobile cerebral veins in the context of positional brain shift: an undescribed risk factor for acute subdural hemorrhage

BACKGROUND

Changes in head position are thought to cause a degree of brain shift in the intracranial cavity. However, little is known on the concurrent shift of the cerebral veins. The present study aimed to investigate the positional shift of the cerebral veins that accompanies brain shift.

METHODS

Sagittal T2-weighted magnetic resonance imaging was performed on 21 consecutive patients lying in the supine and prone positions, using the same sequence. For each patient, imaging data were obtained for the two positions as a pair of images with morphologically best-matched cerebral contours.

RESULTS

The subarachnoid spaces in the parasagittal frontal convexity showed variable reductions related to a postural change from a supine to a prone position, with a mean percent reduction (%Δ) of 17.8 ± 11.7%. Additionally, cerebral cisterns ventral to the brainstem and upper cervical cord were reduced in most patients when lying in a prone position, with a mean %Δ of 16.6 ± 8.7%. In contrast, none of these 130 pairs of identical venous segments located in the parasagittal cerebral convexity showed positional shift. Cadaveric dissections found that the major cortical veins were superficially upheld by the arachnoid membranes.

CONCLUSIONS

The parasagittal major cortical and bridging veins do not seem to show positional shifts. Positional change in the posterior-anterior direction causes a shearing between the frontal cortices and the distributing veins and can be a risk factor for acute subdural hemorrhage, in case of severe head trauma.

High expression of the Notch ligand Jagged-1 is associated with poor prognosis after surgery for colorectal cancer

The importance of Notch signaling in colorectal cancer (CRC) carcinogenesis and progression has previously been presented. Increased expression of Jagged‐1 (JAG1), a Notch ligand, in CRC has been revealed, but the detailed prognostic significance of JAG1 in CRC has not been determined. Protein expression of JAG1 was examined using immunohistochemistry in 158 CRC specimens. Expression of JAG1 and E‐cadherin and their associations with clinicopathologic characteristics, overall survival (OS) and relapse‐free survival (RFS) were evaluated. In vitro studies using compounds to regulate intracellular signaling and small interfering RNA to silence JAG1 were performed in a colon cancer cell line. JAG1 expression in cancerous tissues was weak, moderate or strong in 32%, 36% and 32% of specimens, respectively, and correlated with histologic type and T stage. In multivariate analysis, JAG1 expression, histologic type and lymphatic invasion independently correlated with OS and RFS. The combination of high JAG1 expression and low E‐cadherin expression had an additive effect toward poorer OS and RFS compared with the low JAG1/high E‐cadherin expression subtype. A significant correlation between JAG1 expression and KRAS status was detected in groups stratified as high E‐cadherin expression. In vitro studies suggested that RAS‐MEK‐MAP kinase and the Wnt pathways positively regulated JAG1 expression. Gene silencing with siJAG1 indicated that JAG1 promotes the transition from epithelial to mesenchymal characteristics and cell growth. High expression of JAG1 is regulated by various pathways and is associated with poor prognosis through promoting the epithelial to mesenchymal transition and cell proliferation or maintaining cell survival in CRC.