Detection of parathyroid adenomas with multiphase 4DCT: towards a true four-dimensional technique.

BACKGROUND: Four-dimensional computed tomography (4DCT) is a commonly performed examination in the management of primary hyperparathyroidism, combining three-dimensional imaging with enhancement over time as the fourth dimension. We propose a novel technique consisting of 16 different contrast phases instead of three or four different phases. The main aim of this study was to ascertain whether this protocol allows the detection of parathyroid adenomas within dose limits. Our secondary aim was to examine the enhancement of parathyroid lesions over time. METHODS: For this prospective study, we included 15 patients with primary hyperparathyroidism and a positive ultrasound prior to surgery. We performed 4DCT with 16 different phases: an unenhanced phase followed by 11 consecutive arterial phases and 4 venous phases. Continuous axial scanning centered on the thyroid was performed over a fixed 8 cm or 16 cm coverage volume after the start of contrast administration. RESULTS: In all patients, an enlarged parathyroid lesion was demonstrated, and the mean lesion size was 13.6 mm. The mean peak arterial enhancement for parathyroid lesions was 384 Hounsfield units (HU) compared to 333 HU for the normal thyroid. No significant difference could be found. The time to peak (TTP) was significantly earlier for parathyroid adenomas than for normal thyroid tissue: 30.8 s versus 32.3 s (p value 0.008). The mean slope of increase (MSI) of the enhancement curve was significantly steeper than that of normal thyroid tissue: 29.8% versus 22.2% (p value 0.012). The mean dose length product was 890.7 mGy cm with a calculated effective dose of 6.7 mSv. CONCLUSION: Our 4DCT protocol may allow better visualization of the pattern of enhancement of parathyroid lesions, as enhancement over time curves can be drawn. In this way, wash-in and wash-out of contrast in suspected lesions can be readily demonstrated. Motion artifacts are less problematic as multiple phases are available. Exposure to our proposed 4DCT technique is comparable to that for classic helical 4DCT. Careful selection of parameters (lowering kV and SNR) can help to further reduce the dose.

The "Double-Peak" Pattern of Pituitary Adenoma Intrasellar Pressure and Its Effects on the Microvascular Structure.

OBJECTIVE: The purpose of the present study was to investigate the relationship between the intrasellar pressure (ISP) and the microvascular structure of pituitary adenomas. METHODS: We retrospectively analyzed the ISP in 66 patients with pituitary adenomas. The corresponding microvascular structure was obtained using immunohistochemistry and analyzed for its correlation with the ISP. RESULTS: The average ISP was 25.89 ± 8.27 mm Hg, and the ISP was not related to the size of the adenoma (Pearson correlation coefficient, 0.103; P = 0.415). The ISPs of adenomas with different Knosp grades were significantly different (P < 0.05). From grade 0 to grade 4, at first, the ISP increased with the Knosp grade and reached the first peak at grade 2. It then decreased at grade 3 and increased again at grade 4, showing a "double-peak" pattern. The minimal diameter and perimeter of the microvessels and the vessel-covered area percentage were positively related to the ISP. When these parameters were compared among the adenomas of different Knosp grades, they also exhibited a "double-peak" pattern. CONCLUSIONS: In the present study, we found that with the increase in pituitary adenoma size and invasion of the surrounding tissues, the ISP of pituitary adenomas showed a "double-peak" pattern. The ISP and certain parameters of the microvascular structure are related, because the microvasculature adaptively changes its structure in response to the changing ISP to ensure a sufficient blood supply to the adenoma. The specific mechanism of this phenomenon requires further study.

Preoperative vascular heterogeneity and aggressiveness assessment of pituitary macroadenoma based on dynamic contrast-enhanced MRI texture analysis.

PURPOSE: To assess the vascular heterogeneity and aggressiveness of pituitary macroadenomas (PM) using texture analysis based on Dynamic Contrast-Enhanced MRI (DCE-MRI). METHOD: Fifty patients with pathologically confirmed PM, including 32 patients with aggressive PM (aggressive group) and 18 patients with non-aggressive PM (non-aggressive group), were included in this study. The preoperative DCE-MRI and clinical data were collected from all patients. The features based on Ktrans, Ve, and Kep were generated using Omni-Kinetics software. Independent-samples t-test and Mann-Whitney U test were used for comparison between two groups. Logistic regression analysis was used to determine the optimal model for distinguishing aggressive and non-aggressive PM. RESULTS: Six features related to tumor morphology, 24 features in Ktrans, 20 features in Ve, and 3 features in Kep were significantly different between the aggressive and non-aggressive groups. Volume count, gray-level non-uniformity in Ktrans, voxel value sum in Ve and run-length non-uniformity in Kep (AUC = 0.816, 0.903, 0.785, 0.813) were considered the best feature for tumor diagnosis. After modeling, the diagnosis efficiency of mean model and total model was desirable (AUC = 0.859 and 0.957), and the diagnostic efficiency of morphological, Ktrans, Ve and Kep features model was improved (AUC = 0.845, 0.951, 0.847, 0.804). CONCLUSIONS: Texture analysis based on DCE-MRI elucidates the vascular heterogeneity and aggressiveness of pituitary adenoma. The total model could be used as a new noninvasive method for predicting the aggressiveness of pituitary macroadenoma.

Assessment of microvessel perfusion of pituitary adenomas: a feasibility study using turbo spin-echo-based intravoxel incoherent motion imaging.

OBJECTIVES: To evaluate the feasibility of assessment of microvessel perfusion of pituitary adenomas with intravoxel incoherent motion (IVIM) imaging using single-shot turbo spin-echo-based diffusion-weighted imaging (SS-TSE-DWI). METHODS: We examined 51 consecutive patients with pituitary adenomas (35 non-functioning and 16 functioning) and 32 patients with normal pituitary glands using SS-TSE-DWI IVIM. The diffusion coefficient (D), the perfusion fraction (f), and the pseudo-diffusion coefficient (D*) were calculated pixel-by-pixel for each adenoma and normal pituitary gland. We also obtained the pathological microvessel area (MVA) of each adenoma. The IVIM parameters in adenomas were compared with those in normal pituitary glands using the Mann-Whitney U test. The correlation between the MVA and IVIM f of adenomas was analyzed using Spearman's rank correlation coefficient. RESULTS: The mean D (× 10-3 mm2/s) in adenomas was 0.723 ± 0.253, which was significantly lower than that in normal pituitary glands (0.862 ± 0.128; p < 0.0001). The mean f (%) in adenomas was 10.74 ± 4.51, which was significantly lower than that in normal pituitary glands (13.26 ± 4.32, p = 0.0251). No significant difference was found in the mean D*. We found a significant positive correlation between MVA and f in non-functioning adenomas (ρ = 0.634, p < 0.0001) as well as in all adenomas (ρ = 0.451, p = 0.0009). CONCLUSIONS: Assessment of microvessel perfusion of pituitary adenomas based on SS-TSE-DWI IVIM is feasible. Compared to normal pituitary glands, pituitary adenomas were characterized by lower D and f. KEY POINTS: • Assessment of microvessel perfusion of pituitary adenomas based on SS-TSE-IVIM is feasible. • SS-TSE-IVIM helps with evaluation of the vascularity of pituitary lesions. • Pituitary adenomas were characterized by lower D and f than normal pituitary glands.

Characterization of Skull Base Lesions Using Pseudo-Continuous Arterial Spin Labeling.

PURPOSE: Pseudo-continuous arterial spin labeling (pCASL) is a non-invasive magnetic resonance (MR) perfusion technique. Our study aimed at estimating the diagnostic performance of the pCASL sequence in assessing the perfusion of skull base lesions both qualitatively and quantitatively and at providing cut-off values for differentiation of specific skull base lesions. METHODS: In this study 99 patients with histopathologically confirmed skull base lesions were retrospectively enrolled. Based on a pathological analysis, the lesions were classified as hypervascular and non-hypervascular. Patients were divided into two subgroups according to the anatomical origin of each lesion. The MRI study included pCASL and 3D T1-weighted fat-saturated post-contrast sequences. Of the patients seven were excluded due to technical difficulties or patient movement. The lesions were classified by two raters, blinded to the diagnosis as either hyperperfused or non-hyperperfused, based on the pCASL sequence. The normalized tumor blood flow (nTBF) of each lesion was determined. Qualitative and quantitative characteristics of hypervascular and non-hypervascular lesions were compared. RESULTS: Visual assessment enabled correct classification of 98% of the lesions to be performed. Quantitatively, we found significant differences between the nTBF values for hypervascular and non-hypervascular lesions (p < 0.001) and provided cut-off values, allowing meningioma and schwannoma to be distinguished from meningioma and adenoma. Significant differences were also found within the hypervascular group, namely, paraganglioma was more hyperperfused than meningioma (p = 0.003) or metastases (p = 0.009). CONCLUSION: The present study demonstrates the high diagnostic performance of pCASL in characterizing skull base lesions by either visual assessment or nTBF quantification. Adding the pCASL sequence to the conventional protocol of skull base assessment can be recommended.

Adenoma of colorectal laterally spreading tumor nongranular type with biological phenotypic features similar to cancer.

BACKGROUND AND AIM: Colorectal laterally spreading tumors (LSTs) are morphologically subdivided into granular (LST-G) and nongranular (LST-NG) categories. We aimed to elucidate the differences in oncogenic characteristics between the two types. METHODS: Laterally spreading tumors resected by endoscopic submucosal dissection and surgery from March 2009 to May 2017 were examined for p53 positivity, Ki-67 labeling index (LI), microvessel density, degree of fibrosis, intensities of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT), and expression of acid mucins. We compared these factors between adenomas, noninvasive cancers, and invasive cancers, both LST-G and LST-NG. RESULTS: Ninety-three LST-G (53 adenomas [LST-GA] and 40 cancers [LST-GC]) and 55 LST-NG (24 adenomas [LST-NGA] and 31 cancers [LST-NGC]) were evaluated. Although p53 positivity was lower in LST-GA than in LST-NGA (P < 0.001), there was no difference between LST-GC and LST-NGC. Ki-67 LI was higher in LST-NGA than in LST-GA (P < 0.001) and higher in LST-NGC than in LST-GC of noninvasive cancers (P < 0.001). Microvessel density and degree of fibrosis were higher in LST-NGA than in LST-GA (P < 0.001), and intensities of iNOS and NT were also higher in LST-NGA than in LST-GA (P < 0.001). Expression of acid mucins was lower in LST-NGA than in LST-GA (P < 0.001). Although there were significant differences in p53 positivity, Ki-67 LI, microvessel density, degree of fibrosis, intensities of iNOS and NT, and expression of acid mucins between LST-GA and LST-NGA, these factors were only slightly different between LST-GC and LST-NGC of invasive cancers. CONCLUSIONS: Unlike LST-GA, LST-NGA possessed phenotypic features similar to cancer.

Double pituitary adenomas associated with persistent trigeminal artery: a rare case report and the review of literature.

Multiple pituitary adenomas are rare. We present a quite unique case of double pituitary adenomas associated with persistent trigeminal artery (PTA) treated by endoscopic surgery. To the best of our knowledge, this is the first report in the literature. A 64-year-old woman was referred to our hospital for suspicion of acromegaly. Preoperative magnetic resonance imaging revealed two separate intrasellar masses with intrasellar vascular structure. Right cerebral angiography showed medial-type PTA. The patient underwent endoscopic transsphenoidal surgery and both tumors were resected completely. Postoperative immunohistopathologic examination revealed two histologic types of adenoma: the first tumor was positive for growth hormone (GH), while the second was considered nonfunctioning. Postoperatively, the patient's serum levels of GH and insulin-like growth factor-1 returned to normal. We observed an extremely rare case of double pituitary adenomas associated with PTA. Preoperative neuroimaging and modern endoscopic surgery are valuable to confirm diagnosis of double pituitary adenomas and identify anatomical localization of PTA.

Immediate ex-vivo diagnosis of pituitary adenomas using confocal reflectance microscopy: a proof-of-principle study.

OBJECTIVE The objective of this study was to evaluate the feasibility of using confocal reflectance microscopy (CRM) ex vivo to differentiate adenoma from normal pituitary gland in surgical biopsy specimens. CRM allows for rapid, label-free evaluation of biopsy specimens with cellular resolution while avoiding some limitations of frozen section analysis. METHODS Biopsy specimens from 11 patients with suspected pituitary adenomas were transported directly to the pathology department. Samples were immediately positioned and visualized with CRM using a confocal microscope located in the same area of the pathology department where frozen sections are prepared. An H & E-stained slide was subsequently prepared from imaged tissue. A neuropathologist compared the histopathological characteristics of the H & E-stained slide and the matched CRM images. A second neuropathologist reviewed images in a blinded fashion and assigned diagnoses of adenoma or normal gland. RESULTS For all specimens, CRM contrasted cellularity, tissue architecture, nuclear pleomorphism, vascularity, and stroma. Pituitary adenomas demonstrated sheets and large lobules of cells, similar to the matched H & E-stained slides. CRM images of normal tissue showed scattered small lobules of pituitary epithelial cells, consistent with matched H & E-stained images of normal gland. Blinded review by a neuropathologist confirmed the diagnosis in 15 (94%) of 16 images of adenoma versus normal gland. CONCLUSIONS CRM is a simple, reliable approach for rapidly evaluating pituitary adenoma specimens ex vivo. This technique can be used to accurately differentiate between pituitary adenoma and normal gland while preserving biopsy tissue for future permanent analysis, immunohistochemical studies, and molecular studies.

Angiogenesis and Lymphangiogenesis in the Adrenocortical Tumors.

Adrenocortical tumors (ACT) are common adrenal tumors. The majority of ACTs are non-functioning and benign, while adrenocortical carcinomas (ACC) are rare, usually very aggressive and often metastasized when first diagnosed. Our aim was to assess whether blood and lymph vessel density within ACTs correlate with the malignancy character or tumor functionality. For that, the microvascular distribution was evaluated by immunohistochemistry staining with D2-40 antibody, for lymph vessels and CD-31 antibody, for blood vessels, in ACCs (n = 15), adenomas with Cushing syndrome (n = 9) and non-functioning adenomas (n = 10). The percentage of stained area was quantified by computerized morphometric analysis. D2-40 expression was significantly lower in ACC as compared to adenomas with Cushing syndrome (p < 0.01) and correlated positively with the expression of the steroidogenic acute regulatory protein (StAR) (R2 = 0.553, p < 0.001). CD31 expression was found to be significantly higher in ACC as compared to adenomas with Cushing syndrome (p < 0.05). Our results show that angiogenesis is increased in ACC, suggesting that this phenomenon may have an important role in ACT biological behavior, while lymph vascular density seems to be more closely related to the tumor functional status than malignancy.

The Likelihood of Remnant Nonfunctioning Pituitary Adenomas Shrinking Is Associated with the Lesion's Blood Supply Pattern.

OBJECTIVE: Nonfunctioning pituitary adenomas (NFPA) often shrink after transsphenoidal surgery. However, little is known about the predictors of spontaneous NFPA regression. The aim of this study was to determine whether the blood supply pattern of remnant NFPA lesions was associated with the likelihood of such lesions shrinking. METHODS: A total of 37 remnant tumors in 31 patients who were treated at the Department of Neurosurgery, Yamagata University Hospital, were included in this study. All patients underwent preoperative dynamic 3.0T magnetic resonance imaging (MRI) to evaluate their tumors' arterial blood supplies, followed by endoscopic transsphenoidal surgery and intraoperative 1.5T MRI. Follow-up MRI scans were obtained at 1-2 weeks and 3-6 postoperative months. RESULTS: We detected tumor shrinkage in 15 of 37 (40.5%) remnant tumors on follow-up MRI scans obtained at 3-6 postoperative months. Remnant tumors were found in rostral and caudal locations in 21 and 16 cases, respectively. Rostral remnant tumors were significantly more likely to shrink (P < 0.0001). The tumors were classified into 3 groups according to their blood supply patterns (23 ascending, 6 descending, and 2 monophasic). The ascending blood supply pattern was found to be a positive predictor of tumor shrinkage (P = 0.002). Furthermore, no remnant tumors with rich blood supplies underwent spontaneous regression (P < 0.0001). CONCLUSIONS: Evaluations of the blood supplies of remnant NFPA via preoperative dynamic MRI and the locations of the remnant tumors could be useful for predicting postoperative tumor shrinkage.

Uneven Distribution of Regional Blood Supply Prompts the Cystic Change of Pituitary Adenoma.

BACKGROUND: Previous studies have suggested that the cystic change of pituitary adenoma might be related to the blood supply and metabolism of the tumor; however, the exact pathologic mechanism underlying the cystic change remains unknown. OBJECTIVES: We aimed to assess the features of regional blood supply of pituitary adenoma and examine its relationship with the cystic change of pituitary adenoma. METHODS: Patients (N = 79) with pituitary adenoma admitted to our hospital were divided into the parenchyma group (n = 40) or the cystic change group (n = 39). Dynamic contrast-enhanced magnetic resonance imaging of the pituitary adenoma was conducted for the parenchyma group and the steepest slopes (SSmax, reflecting regional blood supply) at different areas were calculated. The location of cystic change of the pituitary adenoma was recorded and analyzed for the cystic change group. RESULTS: The parenchyma group showed an upper SSmax of 2.52 ± 1.18, a lower SSmax of 2.89 ± 1.46, a left SSmax of 2.71 ± 1.31, and a right SSmax of 2.66 ± 1.29. The difference between the upper and lower SSmax was statistically significant (P < 0.001), with no difference between the left and right regions (P = 0.668). The location of cystic change of the pituitary adenoma was mainly in the upper region, accounting for 48.7% of cases. CONCLUSIONS: Regional blood supply is unevenly distributed in the parenchymal pituitary adenoma, with reduced blood supply in the upper than the lower region. Cystic change mainly occurs in the upper region of pituitary adenoma.

Role of a p53 polymorphism in the development of nonfunctional pituitary adenomas.

Non-functional pituitary adenomas (NFPAs) are among the commonest intracranial neoplasms. While histologically benign, NFPAs sometimes become large enough to limit therapeutic options and reduce quality of life. Investigations of the molecular etiology of NFPAs have failed to identify prevalent genetic changes and, while a role for p53 has been suggested, TP53 gene alterations have yet to be described in NFPAs. We found that the polymorphism rs1042522:C > G in codon 72 of exon 4 of the TP53 gene, whose C variant produces a proline and is more common in most ethnicities, has a G variant producing an arginine in 79.8% of NFPAs (n = 42; p < 1.411 × 10-18 vs. 1000 Genomes database), causing patients to present a decade earlier with symptomatic NFPAs. In cultured NFPA cells, transfection with the rs1042522 G variant versus the C variant reduced expression of cell arrest gene p21 and increased proliferation. These findings suggest that this TP53 polymorphism influences NFPA growth.

Quantitative analysis of anatomical relationship between cavernous segment internal carotid artery and pituitary macroadenoma.

Cavernous segment internal carotid artery (CSICA) injury during endoscopic transsphenoidal surgery for pituitary tumor is rare but fatal. The aim of this study is to investigate anatomical relationship between pituitary macroadenoma and corresponding CSICA using quantitative means with a sense to improve safety of surgery.In this retrospective study, a total of 98 patients with nonfunctioning pituitary macroadenomas undergoing endoscopic transsphenoidal surgeries were enrolled from 2005 to 2014. Intercarotid distances between bilateral CSICAs were measured in the 4 coronal levels, namely optic strut, convexity of carotid prominence, median sella turcica, and dorsum sellae. Parasellar extension was graded and recorded by Knosp-Steiner classification.Our findings indicated a linear relationship between size of pituitary macroadenoma and intercarotid distance over CSICA. The correlation was absent in pituitary macroadenoma with Knosp-Steiner grade 4 parasellar extension.Bigger pituitary macroadenoma makes more lateral deviation of CSICA. While facing larger tumor, sufficient bony graft is indicated for increasing surgical field, working area and operative safety.

Colonoscopic features and malignant potential of sessile serrated adenomas: comparison with other serrated lesions and conventional adenomas.

AIM: Sessile serrated adenomas/polyps (SSA/Ps) have been proposed as precursors of colorectal cancer. The aims of this investigation were to compare the endoscopic findings of SSA/Ps with those of other serrated lesions and to compare the histological findings of SSA/Ps with those of conventional adenomas. METHOD: We retrospectively reviewed colonoscopy records at our institution from 1984 to 2013 and identified cases of endoscopically or surgically resected conventional adenomas and serrated lesions, including SSA/Ps, hyperplastic polyps (HPs) and traditional serrated adenomas (TSAs). The colonoscopic findings of SSA/Ps were compared with those of the other two serrated lesions and histological findings were compared among all groups of lesions. RESULTS: There were 79 HPs in 68 patients, 77 SSA/Ps in 63 patients, 167 TSAs in 145 patients and 6324 conventional adenomas in 4129 patients. The inverted type and flat-elevated type were more frequent among SSA/Ps than among the other two types of serrated lesions. Magnifying colonoscopy revealed that a round and open pit pattern, expanded crypt openings and varicose microvascular vessels were more frequently observed among SSA/Ps than among the other types. The incidence of high-grade dysplasia or carcinoma among SSA/Ps (13.0%) was significantly higher than that among HPs (0%, P < 0.001) and equivalent to that among conventional adenomas (12.3%). CONCLUSION: SSA/Ps have colonoscopic features distinct from those of HPs and TSAs. The malignant potential of SSA/Ps seems to be equal to that of conventional adenomas.

Evaluation of Fine Feeding System and Angioarchitecture of Giant Pituitary Adenoma--Implications for Establishment of Surgical Strategy.

BACKGROUND: Giant pituitary adenomas carry higher surgical risks despite recent advances in microsurgical and/or endoscopic surgery, and postoperative acute catastrophic changes without major vessel disturbance are still extremely difficult to predict, may manifest as postoperative pituitary apoplexy, and are associated with poor outcomes. METHODS: Eight males and 4 females aged 31-72 years (mean 50.7 years) with giant pituitary adenomas underwent preoperative investigation of fine angioarchitecture using C-arm cone-beam computed tomography with a flat-panel detector. Angiographical findings were used to decide the surgical routes and compared with clinical outcome. RESULTS: Feeding arteries were verified in 10 of 12 patients, whereas no feeding arteries were evident in 2 patients. The patients were divided into the faint tumor staining group and the significant staining group, which was reconfirmed by region of interest analysis. The former group had faint supply from the ipsilateral superior hypophyseal arteries and meningohypophyseal trunk, and the latter group had significant supply from the meningohypophyseal and inferolateral trunks, which passed centrifugally from the inferoposterior pole of the tumor. All patients were treated through the extended transsphenoidal approach. Intraoperative bleeding was significantly greater in the latter group (P = 0.013). All patients had improvement of neurologic deficit and were released from the intensive care unit within a few days. CONCLUSIONS: Major blood supply of giant pituitary adenomas originates from branches of the infraclinoidal portion of the internal carotid artery, different from the normal anterior pituitary gland. Surgical route should depend on not only tumor shape and extension but also feeding systems.

Primary meningeal melanocytoma of the sellar region: review of the literature and differential diagnosis with special reference to angiographical features.

PURPOSE: Primary intracranial melanocytomas are rare neoplasms, especially in the sellar region. Intracranial melanocytoma is usually a dural-based tumor, fed by dural arterial branches in a manner similar to meningioma. Primary sellar melanocytoma may be misdiagnosed as hemorrhagic pituitary macroadenoma, spindle cell oncocytoma, and intrasellar meningioma. These tumors differ in some radiological respects, but are difficult to differentiate preoperatively. METHODS: Only five cases of primary sellar/suprasellar melanocytic tumors, excluding melanomas have been reported thus far. In this paper, we report an instructive new case of a 31-year-old woman presenting with a 2-year history of amenorrhea and an intrasellar mass with suprasellar extension, suggestive of hemorrhagic pituitary adenoma. RESULTS: Transsphenoidal surgical excision was difficult due to extensive bleeding from the lesion, and at the time, the tumor could not be diagnosed histopathologically. Six years later, we operated again because of tumor regrowth. Angiography revealed a hypervascular tumor, which was fed from the dorsal sellar floor. We had difficulty resecting the tumor, but achieved total removal. Our case had typical radiographic characteristics of melanocytoma, revealed by both magnetic resonance imaging and angiography. However, it was difficult to reach a final diagnosis. Further histopathological examination, including immunohistochemical and ultrastructural studies, was helpful for diagnosis of melanocytoma. CONCLUSIONS: Primary sellar melanocytic tumors are derived from melanocytes in the meningeal lining of the sellar floor or in the diaphragm sellae, based on both embryological assumptions and the clinical findings of our case. We discuss the problems of differential diagnosis and management of primary sellar melanocytic tumors.

Tumour-associated fibroblasts contribute to neoangiogenesis in human parathyroid neoplasia.

Components of the tumour microenvironment initiate and promote cancer development. In this study, we investigated the stromal component of parathyroid neoplasia. Immunohistochemistry for alpha-smooth muscle actin (α-SMA) showed an abundant periacinar distribution of α-SMA(+) cells in normal parathyroid glands (n=3). This pattern was progressively lost in parathyroid adenomas (PAds; n=6) where α-SMA(+)cells were found to surround new microvessels, as observed in foetal parathyroid glands (n=2). Moreover, in atypical adenomas (n=5) and carcinomas (n=4), α-SMA(+) cells disappeared from the parenchyma and accumulated in the capsula and fibrous bands. At variance with normal glands, parathyroid tumours (n=37) expressed high levels of fibroblast-activation protein (FAP) transcripts, a marker of tumour-associated fibroblasts. We analysed the ability of PAd-derived cells to activate fibroblasts using human bone-marrow mesenchymal stem cells (hBM-MSCs). PAd-derived cells induced a significant increase in FAP and vascular endothelial growth factor A (VEGFA) mRNA levels in co-cultured hBM-MSCs. Furthermore, the role of the calcium-sensing receptor (CASR) and of the CXCL12/CXCR4 pathway in the PAd-induced activation of hBM-MSCs was investigated. Treatment of co-cultures of hBM-MSCs and PAd-derived cells with the CXCR4 inhibitor AMD3100 reduced the stimulated VEGFA levels, while CASR activation by the R568 agonist was ineffective. PAd-derived cells co-expressing parathyroid hormone (PTH)/CXCR4 and PTH/CXCL12 were identified by FACS, suggesting a paracrine/autocrine signalling. Finally, CXCR4 blockade by AMD3100 reduced PTH gene expression levels in PAd-derived cells. In conclusion, i) PAd-derived cells activated cells of mesenchymal origin; ii) PAd-associated fibroblasts were involved in tumuor neoangiogenesis and iii) CXCL12/CXCR4 pathway was expressed and active in PAd cells, likely contributing to parathyroid tumour neoangiogenesis and PTH synthesis modulation.

Intraoperative indocyanine green videoangiography for identification of pituitary adenomas using a microscopic transsphenoidal approach.

PURPOSE: Initial successful surgical treatment of pituitary adenomas is crucial to reach long-term remission. Indocyanine green (ICG) videoangiography (VA) is well established in vascular neurosurgery nowadays and several reports described ICG application in brain tumor surgery. We designed this study to evaluate the feasibility of intravenous application of ICG and visualisation of a pituitary lesion via the fluorescence mode of the operation microscope. METHODS: 22 patients with pituitary adenomas were treated with transsphenoidal microsurgery and were included in this study. Intraoperatively 25 mg ICG was administered intravenously and visualized via the fluorescence mode of the operation microscope (Pentero/Zeiss). RESULTS: 22 patients qualified for transsphenoidal surgery presenting with different clinical symptoms (13 patients with acromegaly, 6 with M. Cushing and 3 with other symptoms like vision disorder or dizziness) and identification of a pituitary lesion (21 of 22 patients) in preoperative MR-imaging (mean diameter: 9 mm; SD 3.6; 6 macroadenomas, 15 microadenomas, 1 MR-negative). In all 22 patients ICG VA was performed during surgery. No technical failures or adverse events after drug administration occurred. Visualization was optimal approximately 2.4 min after intravenous application. In all patients the adenoma could be detected via two different types of visualization: direct visualization by fluorophore emission versus indirect detection of the adenoma by a lower ICG fluorescence compared to the surrounding tissue. CONCLUSION: Our data show that intraoperative ICG VA can be a useful and easily applicable additional diagnostic tool for visualization of pituitary lesions using the microscopic approach.

Crosstalk between tumor blood vessels heterogeneity and hormonal profile of pituitary adenomas: evidence and controversies.

AIM: Pituitary adenomas are intracranial tumors with controversial histopathology and heterogeneous clinical behaviour. Angiogenesis and tumor blood vessels' role in pathogenesis, remain one of the great pituitary tumor mysteries. No connection between tumor vessel heterogeneity, hormonal profile and biological behaviour has been reported. We aimed to study pituitary adenomas blood vessels concerning their immature, intermediate or mature phenotype and microvessel density, correlated with immunohistochemical hormonal profile and hormone values in serum and cerebrospinal fluid. MATERIALS AND METHODS: We classified pituitary adenomas according to hormone profile and we applied a double immunostaining highlighting both endothelial and perivascular cells for a more accurate assessment of blood vessel types. RESULTS: Overall microvessel density was found to be highest in growth hormone-secreting adenomas (48.51 ± 12.15) and lowest in prolactinomas (29.15 ± 18.78). When we differentially counted tumor blood vessels we observed a predominance of immature and intermediate blood vessels compared to mature ones. A significant correlation was found between immature tumor blood vessels and tissue prolactin expression, as assessed by immunhistochemistry (p=0.044). A partial correlation was found between serum (p=0.036) and cerebrospinal prolactin values (p=0.006) with immature and intermediate blood vessels. Also, a partial correlation has been reported only between mature blood vessels and cerebrospinal fluid prolactin values (p=0.008). No correlation was obtained for other types of pituitary adenomas. CONCLUSION: Our results suggest a strong involvement of prolactin with a dual role in pituitary adenomas vasculature remodelling by acting both on endothelial and perivascular cells, a finding that could partially explain discrepancies between clinical diagnosis and hormonal profile.