Directional Regulation of Extrasellar Extension by Sellar Dura Integrity and Intrasphenoidal Septation In Pituitary Adenomas.

OBJECTIVE: Pituitary macroadenomas extend into the extrasellar space, such as the sphenoid sinus, cavernous sinuses, and suprasellar region. However, factors that regulate the direction of their extensions into the surrounding anatomical structures remain unknown. METHODS: This retrospective study included 162 patients who were treated for pituitary adenomas that had maximum diameters greater than 20 mm. According to the direction of adenoma extension, patients were divided into 4 groups: group A, inferior into the sphenoid sinus; group B, lateral into the cavernous sinus; group C, suprasellar region with enlarged sella turcica; and group D, supraellar region without enlarged sella turcica. Several anatomical structures surrounding the sella turcica were evaluated statistically, and multivariate logistic regression analysis was performed if the structures met the determining factors of adenomas extensions. RESULTS: The maximum diameter of adenomas was significantly larger in groups A and D. The maximum diameter of the diaphragmatic foramen was largest in group C (19.3 mm) and was significantly narrower in groups B (12.7 mm) and D (12.5 mm). Intrasphenoid septation, attached on the midline of the sella turcica, was observed most frequently in group D (78.6%) and was not detectable in group A (0%). Extension into the cavernous sinus, classified as dural discontinuity, was highly prevalent in group B (80.0%) and was uncommon in group C (12.3%). Erosion of the posterior clinoid process was most apparent in group B (92.0%). CONCLUSIONS: The integrity of the sella dura and the intrasphenoid septation can regulate adenoma extension by encouraging their growth towards paths of least resistance.

Delayed Occurrence of Diabetes Insipidus After Transsphenoidal Surgery with Radiologic Evaluation of the Pituitary Stalk on Magnetic Resonance Imaging.

BACKGROUND: Diabetes insipidus (DI) is a major complication of transsphenoidal surgery (TSS). DI usually occurs within a couple of days after TSS. Delayed occurrence of postoperative DI is rarely observed and its developing mechanisms remain unknown. METHODS: Six patients were identified as having postoperative delayed DI, which was defined as DI that first occurred 2 or more weeks after TSS. They consisted of 1 male and 5 females, and their mean age was 38.3 years (range, 10-76 years). Five patients were histologically diagnosed with Rathke cleft cyst (RCC), and one had RCC coexisting with prolactin-secreting adenoma. Sequential T1-weighted magnetic resonance imaging was evaluated for hyperintensity (HI) in the pituitary stalk and the posterior lobe, indicating the location of antidiuretic hormone. RESULTS: No patients had any DI before TSS. Delayed DI occurred 2 weeks to 3 months after TSS and persisted for 2 weeks to 5 months. T1-weighted magnetic resonance imaging showed that the HI in the posterior lobe became faint but did not disappear after DI occurrence, and their intensities increased with recovery from DI. In contrast, the HI in the pituitary stalk was found faintly preoperatively and turned clear postoperatively and decreased with recovery from DI. The morphologic patterns were dependent on DI duration. CONCLUSIONS: In the delayed occurrence of DI, it was suggested that preoperative antidiuretic hormone transport was mildly congested yet not completely blocked when DI manifested postoperatively. Gradual spreading of inflammation to the infundibulum after RCC removal was considered as 1 possible mechanism of this delayed DI development.

Contribution of sellar dura integrity to symptom manifestation in pituitary adenomas with intratumoral hemorrhage.

PURPOSE: Although hemorrhage within pituitary adenomas frequently exacerbates the symptoms, there are many grades of severity. Moreover, the contributing factors for symptom severity are still controversial. METHODS: This retrospective study included 82 patients who underwent transsphenoidal surgery for pituitary adenomas with intratumoral hemorrhage. The grades of preoperative symptoms were classified into group A, asymptomatic or minor symptoms; group B, moderate symptoms sufficient for complain; and group C, severe symptoms disturbing daily life. RESULTS: The hemorrhage volume within an adenoma was significantly higher in group C (92.6%) than in groups A (48.6%) and B (58.7%). Both headache and diplopia were dominant in group C, occurring in 72.2% and 27.8% of the patients, respectively. In group C, there was no significant difference in frequency between adenoma extensions into the sphenoid sinus (0%) and involvement of the cavernous sinus of Knosp grade 4 (0%), and extensions into the suprasellar region were not common (38.9%). The most distinctive feature was that "no extrasellar extension" was found only in group C (41.2%), and "multidirectional extension" was not detected in this group (0%). Multiple regression analysis revealed that the most powerful determining factors were the high frequencies of intratumoral hemorrhage and lack of extrasellar and multidirectional extensions. CONCLUSION: Rapid volume expansion of a hematoma and lack of extension or unidirectional extension might lead to significant compression of the sellar and surrounding structures. Of note, the integrity of the sellar dura might contribute to the acute onset of symptom manifestations caused by hemorrhage in pituitary adenomas.

Preoperative Evaluation of the Interface Between Tuberculum Sellae Meningioma and the Optic Nerves on Fast Imaging with Steady-State Acquisition for Extended Endoscopic Endonasal Transsphenoidal Surgery.

INTRODUCTION: Endoscopic endonasal transsphenoidal surgery (EETS) is increasingly applied to treat tuberculum sellae meningiomas. However, if the tumor adheres firmly to the optic nerve, dissection of the interface between both structures should be prudent to preserve visual function. The purpose of this study was to investigate whether tumor adhesion to the optic nerve can be predicted preoperatively by fast imaging with steady-state acquisition (FIESTA). METHODS: Twenty-two patients with tuberculum sellae meningioma treated with EETS were retrospectively identified. Clinical characteristics, radiologic studies, intraoperative findings, and outcomes were reviewed from their clinical charts. RESULTS: Patients' symptoms included visual function impairment in 18 patients and headaches in 4 patients. Symptoms were resolved in 19 patients after operation. Preoperative radiologic evaluation was performed in 44 sides (22 patients) of the interface between tumors and the optic nerves and showed absence of peritumoral hyperintensity on FIESTA in 7 sides in 7 patients. In 5 of the 7 sides, tumor dissection was complicated by firm adhesion to the optic nerves. Among these cases, visual functions were unchanged in 1 patient after complete removal of the adhesion but substantially improved in 3 patients after partial resection. In the remaining 37 sides with preoperative peritumoral hyperintensity, no adhesion was found between both structures intraoperatively. CONCLUSIONS: Absence of peritumoral hyperintensity between tuberculum sellae meningioma and the optic nerve on FIESTA may indicate firm adhesion at the interface, severely complicating complete removal. Preoperative recognition of this adhesion is important for safe tumor removal and preservation of visual functions.

MR Spectroscopy to Distinguish between Supratentorial Intraventricular Subependymoma and Central Neurocytoma.

PURPOSE: The purpose of this study was to discriminate supratentorial intraventricular subependymoma (SIS) from central neurocytoma (CNC) using magnetic resonance spectroscopy (MRS). METHODS: Single-voxel proton MRS using a 1.5T or 3T MR scanner from five SISs, five CNCs, and normal controls were evaluated. They were examined using a point-resolved spectroscopy. Automatically calculated ratios comparing choline (Cho), N-acetylaspartate (NAA), myoinositol (MI), and/or glycine (Gly) to creatine (Cr) were determined. Evaluation of Cr to unsuppressed water (USW) was also performed. Mann-Whitney U test was carried out to test the significance of differences in the metabolite ratios. Detectability of lactate (Lac) and alanine (Ala) was evaluated. RESULTS: Although a statistically significant difference (P < 0.0001) was observed in Cho/Cr among SIS, control spectra, and CNC, no statistical difference was noted between SIS and control spectra (P = 0.11). Statistically significant differences were observed in NAA/Cr between SIS and CNC (P = 0.04) or control spectra (P < 0.0001). A statistically significant difference was observed in MI and/or Gly to Cr between SIS and control spectra (P = 0.03), and CNC and control spectra (P < 0.0006). There were no statistical differences between SIS and CNC for MI and/or Gly to Cr (P = 0.32). Significant statistical differences were found between SIS and control spectra (P < 0.0053), control spectra and CNC (P < 0.0016), and SIS and CNC (P < 0.0083) for Cr to USW. Lac inverted doublets were confirmed in two SISs. Triplets of Lac and Ala were detected in four spectra of CNC. CONCLUSION: The present study showed that MRS can be useful in discriminating SIS from CNC.

Cranial Pachymeningeal Involvement in POEMS Syndrome: Evaluation by Pre- and Post-contrast FLAIR and T1-weighted Imaging.

PURPOSE: To evaluate the cranial pachymeningeal involvement of polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes (POEMS) syndrome using pre- and post-contrast fluid-attenuated inversion recovery (FLAIR) and T1-weighted imaging (T1WI). METHODS: The appearance of pachymeningeal involvement in nine cases of POEMS syndrome was evaluated using pre- and post-contrast FLAIR and T1WI. The degree of pachymeningeal thickening was graded as normal or abnormal using pre-contrast FLAIR. The degrees of contrast enhancement effect were evaluated based on pre- and post-contrast images, and recorded in each of three separate anatomical areas, i.e., the falx cerebri, cerebral convexity, and tentorium cerebelli. The degrees of contrast enhancement of pachymeninges were graded as not detected (ND), positive, or prominent on post-contrast FLAIR, and normal range (NR), positive, and prominent on post-contrast T1WI. RESULTS: Pre-contrast FLAIR demonstrated 41% of pachymeningeal anatomical regions as areas of thickening. Post-contrast FLAIR did not detect any contrast enhancement on 26% of the regions but showed positive enhancement on 30% and prominent enhancement on 44%. Post-contrast T1WI showed normal range enhancement on 48%, positive enhancement on 11%, and prominent enhancement on 41% of the regions. Post-contrast FLAIR showed the highest percentage for detection of pachymeningeal abnormalities (74%). CONCLUSION: Post-contrast FLAIR may contribute to objective judgment in the evaluation of pachymeningeal involvement in POEMS syndrome.

Prediction of postoperative diabetes insipidus using morphological hyperintensity patterns in the pituitary stalk on magnetic resonance imaging after transsphenoidal surgery for sellar tumors.

PURPOSE: Diabetes insipidus (DI) remains a complication of transsphenoidal surgery (TSS) for sellar and parasellar tumors. Antidiuretic hormone (ADH) appears as hyper intensity (HI) in the pituitary stalk and the posterior lobe of the pituitary gland on T1-weighted magnetic resonance (MR) imaging. Its disappearance from the posterior lobe occurs with DI, indicating a lack of ADH. The appearance of HI in the pituitary stalk indicates disturbances in ADH transport. METHODS: This retrospective study included 172 patients undergoing TSS for sellar tumors at our institute from 2006 to 2014. Sequential T1-weighted MR images without enhancement were evaluated for HI in the pituitary stalk and the posterior lobe to assess the localization of ADH before and at intervals after TSS. DI was assessed pre- and postoperatively. HI in the pituitary stalk showed the following morphology: (1) ovoid in the distal end of the pituitary stalk (group A), (2) linear in the distal part of the pituitary stalk (group B), (3) linear in the whole pituitary stalk (group C). RESULTS: Preoperative DI occurred in 6 patients (3.5 %) with no HI observed in the posterior lobe. Postoperative DI was transient in 82 patients (47.7 %), and permanent in 11 (6.4 %). One week after surgery, HI was absent in the posterior lobe in 74 patients (43.0 %), and present in the pituitary stalk in 99 patients (57.6 %); both were significantly correlated with postoperative DI (p < 0.001). The absence of HI in the posterior lobe (A, 48.9 %; B, 68.3 %; C, 92.3 %), persistence of DI (A, 3.7 days; B, 45.9 days; C, 20.5 months), and duration until HI recovery in the posterior lobe (A, 3.6 months; B, 6.8 months; C, 22.9 months) were greatest in group C, followed by group B, and then group A. Fourteen group A patients did not have postoperative DI despite having HI in the pituitary stalk and the posterior lobe. Four group C patients developed permanent DI with persistence HI in the pituitary stalk. CONCLUSION: HI in the pituitary stalk and its absence in the posterior lobe indicated postoperative DI, which was transient if HI was detected in the pituitary stalk. DI duration could be predicted by the length of HI in the pituitary stalk, which corresponded to the degree of ADH transport obstruction.

Malignant transformation of diffuse infiltrating glial neoplasm after prolonged stable period initially discovered with hypothalamic hamartoma.

We present a case of malignant transformation of diffuse infiltrating glial neoplasm after a prolonged stable period on magnetic resonance imaging (MRI) and spectroscopy (MRS) initially discovered with a hypothalamic hamartoma. Although MRI and MRS suggest the possibility of malignant transformation in future, they cannot precisely predict the timing of rapid growth.

Differences between glioblastomas and primary central nervous system lymphomas in 1H-magnetic resonance spectroscopy.

PURPOSE: The present study aimed to distinguish between glioblastomas and primary central nervous system lymphomas (PCNSLs) using (1)H-magnetic resonance spectroscopy (MRS), especially glutamate (Glu)/creatine (Cr) and Glu/Glu+glutamine (Gln) ratios. MATERIALS AND METHODS: A total of 46 patients (31 cases diagnosed with glioblastoma, 15 with PCNSL) were examined by in vivo single-voxel proton (1)H-MRS with a 3-T MR imaging system. Differences in absolute concentration of Cr, choline/Cr, lipid (1.3 ppm)/Cr, Glu+Gln/Cr, Glu/Cr, and Glu/Glu+Gln ratios among groups were evaluated with Mann-Whitney U tests. RESULTS: PCNSLs [3.408 ± 1.194 (standard deviation)] showed significantly higher Glu/Cr ratios as compared to glioblastomas (2.220 ± 0.942; P = 0.003) [Glu/Cr cutoff ratio of 2.509 showed a sensitivity of 88 % (7/8) and a specificity of 92 % (22/24)], while glioblastomas (0.539 ± 0.098) showed significantly lower Glu/Glu+Gln ratios as compared to PCNSLs (0.728 ± 0.147; P < 0.001) [Glu/Glu+Gln cutoff ratio of 0.558 showed a sensitivity of 69 % (18/26) and a specificity of 100 % (13/13)]. And PCNSLs (1.101 ± 0.387) showed significantly higher Cho/Cr ratios as compared to glioblastomas (0.850 ± 0.465; P = 0.026). CONCLUSION: Glu/Cr, Glu/Glu+Gln, and Cho/Cr ratios may be useful in distinguishing between glioblastomas and PCNSLs.

Prognostic paradox: brain damage around the glioblastoma resection cavity.

Hyperintense lesions around the resection cavity on magnetic resonance diffusion-weighted imaging (MR-DWI) frequently appear after brain tumor surgery due to the damage of surrounding brain. The putative connection between the lesion and the prognosis for patients with glioblastoma (GBM) was explored. This retrospective study reviewed consecutive sixty-one patients with newly diagnosed GBM. Postoperative MRI was performed within 2 weeks after the initial surgery. We classified the cases into two groups depending on whether DWI hyperintense lesions were observed or not [DWI(+) group and DWI(-) group]. Progression-free survival (PFS) and overall survival (OS) were compared between the two groups. Forty-two patients were identified. The various extents of hyperintense lesions around the resection cavity were observed in 28/42 (66.7%) cases. In the DWI(+) and DWI(-) groups, median PFS was 10.0 [95% confidence interval (CI) 8.4-11.5] and 6.7 (95% CI 4.9-8.5) months, respectively (p = 0.042), and median OS was 18.0 (95% CI 12.2-23.8) and 17.0 (95% CI 15.7-18.3) months, respectively (p = 0.254). On multivariate analysis, the presence of DWI hyperintense lesion was more likely to be an independent predictor for 6-month PFS (p = 0.019; HR, 0.038; 95% CI 0.002-0.582). Tumor recurrence appeared outside the former DWI hyperintense lesion. Hyperintense lesions surrounding the resected GBM on MR-DWI might be a favorable prognostic factor in patients with GBM.

Automated MR spectroscopy of intra- and extraventricular neurocytomas.

PURPOSE: We evaluated the automated magnetic resonance spectroscopic (MRS) characteristics of intra- and extraventricular neurocytomas. MATERIALS AND METHODS: One extra- and 4 intraventricular neurocytomas were studied. Automated single-voxel proton MRS was performed with a 1.5 T MR scanner. The results of 6 total automated MR spectra were analyzed for each tumor. RESULTS: Lactate resonance was detected as a doublet in 3 MR spectra of 2 intraventricular neurocytomas. A peak corresponding to N-acetylaspartate (NAA) was small in 5 MR spectra of 4 intraventricular neurocytomas. Creatine (Cr) resonance was detected in all 6 MR spectra. Prominent choline (Cho) resonance was found in all 6 MR spectra. The myoinositol (MI) and/or glycine (Gly) peaks were large in 3 MR spectra of 2 intraventricular neurocytomas. CONCLUSION: The presence of the NAA signal and high MI and/or Gly signals may be characteristic features of intraventricular neurocytomas. A combination of prominent Cho resonance and detectable Cr resonance is a common feature of both intra- and extraventricular neurocytomas.

Anatomical study of the confluence of the sinuses with contrast-enhanced magnetic resonance venography.

INTRODUCTION: It is important that each dural sinus can be recognized during brain surgery and that the venous route can be used for interventional procedures. In this study, the anatomical features and patterns of the confluence of the sinuses were analyzed. METHODS: The technique of contrast-enhanced three-dimensional magnetic resonance venography was used in 549 patients. RESULTS: There were many anatomical variations in the confluence of the sinuses. Most cases had wide communication between the right and left transverse sinuses. CONCLUSION: Careful examination of the confluence of the sinuses is essential for the preoperative evaluation of posterior cranial fossa lesions and interventional procedures using the venous route.

MR findings of nine cases of palatal tumor.

PURPOSE: To assess the magnetic resonance imaging (MRI) findings of pathologically confirmed palatal tumors. METHODS: Nine cases of palatal tumor were studied. Clinical data, MRI findings, and pathological diagnoses were evaluated. RESULTS: Five cases were tumors of the hard palate and four of the soft palate. Signal intensity on T1-weighted images varied, and hyperintensity was observed on T2-weighted images. Adenoid cystic carcinoma and diffuse large B cell lymphoma showed homogenous signal intensity. Other tumors showed heterogeneous signal intensities. On dynamic contrast analysis, malignant pleomorphic adenoma, adenoid cystic carcinoma, diffuse large B cell lymphoma, and peripheral T cell lymphoma showed early enhancement. On post-contrast T1-weighted images, hard palate pleomorphic adenoma, malignant pleomorphic adenoma, adenoid cystic carcinoma, diffuse large B cell lymphoma, and peripheral T cell lymphoma showed strong enhancement. Although the borders of the tumors were classified as clear in 6 cases treated surgically, macroscopic and microscopic borders of the tumors were unclear. Adenoid cystic carcinoma and hard palate diffuse large B cell lymphoma invaded the maxillary bone. CONCLUSION: Magnetic resonance findings of palatal tumor varied in different histologies. Even with a small palpable portion, malignant tumors could directly infiltrate surrounding structures, which demonstrated well on MRI.

Dynamic MR imaging for diagnosis of lesions adjacent to pituitary gland.

In this study, we evaluated the usefulness of dynamic studies for the preoperative diagnosis of tumor lesions adjacent to the pituitary gland. We examined 13 tumors. We obtained pre- and post-contrast thin slice T1-weighted images of the sellar regions. FSE sequences were used for dynamic study. The capability to distinguish the tumor from the pituitary gland and additional information obtained from the dynamic study were evaluated. Two meningiomas were identified more clearly on the dynamic than on the delayed study. In two cavernous hemangiomas, the peripheral nodular stains gradually increased during the dynamic study. For the preoperative evaluation of lesions adjacent to the pituitary gland, the dynamic study can often identify the lesions more clearly and may provide additional information.

CO2 demonstration of multiple extravasations into a subcapsular hematoma of the liver.

In a case of esophageal cancer with liver metastases, rupture of a liver metastasis resulted in subcapsular hematoma of the liver. Digital subtraction angiography with carbon dioxide showed multiple extravasations at the surface of the liver suggesting multiple ruptures of the penetrating hepatic capsular arteries. It was suggested that these findings are not rare in cases of subcapsular hematoma; however, they have received little attention.

Metastasis of breast cancer to intracranial meningioma: case report.

Metastasis of systemic cancer to intracranial tumors is a rare event. The authors report a case of 49-year-old woman with such occurrence, whose breast cancer metastasized to a preexisting parasagittal meningioma at a postoperative interval of 1.5 years. She was admitted to our hospital because of progressive right hemiparesis. Magnetic resonance imaging revealed newly emerged perifocal edema and inhomogeneous contrast enhancement of the meningioma. High choline/creatine ratio and lactate/lipid peak on proton magnetic resonance spectroscopy suggested malignancy. She underwent a tumor resection, and pathologic examination revealed intratumoral metastasis of breast cancer in a transitional meningioma. Immunoreactivity of E-cadherin was detected in both meningioma and breast cancer cells. It is suggested that abrupt appearance of symptoms, inhomogeneous enhancement, and perifocal edema of meningioma is a sign of intratumoral metastasis from systemic cancers.

Thrombosed varicose vein in the sternocleidomastoid muscle.

A thrombosed varicose vein arising in the neck is quite rare. A 68-year-old Japanese male was referred to our hospital because of a mass in his left upper neck. The mass did not change in size in response to strain resulting from Valsalva's manouvre. Magnetic resonance imaging (MRI) showed iso-signal intensity of the mass on T1-weighted images and a target-like signal arrangement (concentric hyper-, hypo-, hyper-signal intensity from outside to inside) on T2-weighted images. Surgical excision revealed that the tumour arose from the intramuscular small vein in the sternocleidomastoid muscle. The pathological examination revealed the mass to be a thrombosed varicose vein with capillarization in the dilated vein wall. The de-oxygenation and degradation of haemoglobin were thought to be responsible for these characteristic MRI findings. The concentric signal distribution on MRI strongly suggested this pathology.