Single-cell transcriptome analysis reveals tumoral microenvironment heterogenicity and hypervascularization in human carotid body tumor

Carotid body tumor (CBT) is a rare neck tumor located at the adventitia of the common carotid artery bifurcation. The prominent pathological features of CBT are high vascularization and abnormal proliferation. However, single-cell transcriptome analysis of the microenvironment composition and molecular complexity in CBT has yet to be performed. In this study, we performed single-cell RNA sequencing (scRNA-seq) analysis on human CBT to define the cells that contribute to hypervascularization and chronic hyperplasia. Unbiased clustering analysis of transcriptional profiles identified 16 distinct cell populations including endothelial cells (ECs), smooth muscle cells (SMCs), neuron cells, macrophage cells, neutrophil cells, and T cells. Within the ECs population, we defined subsets with angiogenic capacity plus clear signs of later endothelial progenitor cells (EPCs) to normal ECs. Two populations of macrophages were detectable in CBT, macrophage1 showed enrichment in hypoxia-inducible factor-1 (HIF-1) and as well as an early EPCs cell-like population expressing CD14 and vascular endothelial growth factor. In addition to HIF-1-related transcriptional protein expression, macrophages1 also display a neovasculogenesis-promoting phenotype. SMCs included three populations showing platelet-derived growth factor receptor beta and vimentin expression, indicative of a cancer-associated fibroblast phenotype. Finally, we identified three types of neuronal cells, including chief cells and sustentacular cells, and elucidated their distinct roles in the pathogenesis of CBT and abnormal proliferation of tumors. Overall, our study provided the first comprehensive characterization of the transcriptional landscape of CBT at scRNA-seq profiles, providing novel insights into the mechanisms underlying its formation.

Glioblastoma simulating an arteriovenous malformation: a case report

Glioblastoma is the most common primary malignant brain tumor in adults. It is enhanced by the abnormal proliferation of central nervous system cells called astrocytes. Microvascular endothelial proliferation is one of the criteria for a histological diagnosis. Hypervascular glioblastoma simulating an arteriovenous malformation is an involuntary manifestation and constitutes a rare entity.

Case presentation

The authors report a case of a 44-year-old patient with no history followed. Symptoms began 6 months ago with the gradual onset of headaches without vomiting or seizures associated with a drop in normal visual acuity without neurological deficit. Cerebral imaging including cerebral angiography concluding with a right parieto-occipital cerebral process probably associated with an arteriovenous malformation.

Clinical discussion

The management was surgical by biopsy after a right parieto-occipital bone flap concluding in glioblastoma. The patient needs chemotherapy and radiotherapy sessions with good clinical evolution.

Conclusion

The coexistence of an arteriovenous malformation and glioblastoma remains an association whose pathophysiology still remains to be explored.

A large adrenocortical adenoma surrounded with a renal arteriovenous malformation

INTRODUCTION

Large adrenal adenomas are clinically rare. We report a case of a large adrenal adenoma with a renal arteriovenous malformation, mimicking a malignant adrenal tumor in preoperative imaging.

CASE PRESENTATION

A 66-year-old woman presented to a local hospital with abdominal pain. A right adrenal tumor was detected, 66 mm in diameter and surrounded by thick and tortuous vessels. Based on the imaging findings, pheochromocytoma was suspected. However, clinical symptoms and endocrine abnormalities were absent, and radionuclide accumulation in scintigraphy was negative. Laparoscopic right adrenalectomy was performed. Intraoperatively, a notable growth of vessels forming a nidus surrounding the tumor was observed. Pathologically, this was diagnosed as an adrenocortical adenoma in conjunction with a renal arteriovenous malformation.

CONCLUSION

We report a case of a large adrenal tumor surrounded with an arteriovenous malformation. To the best of our knowledge, this is the first reported case of this combination.

Effect of focal and diffuse hypervascularization as cystoscopic findings on predicting intravesical therapy response in patients with bladder pain syndrome

OBJECTIVE

To define the relationship between cystoscopic findings, including novel findings such as the hypervascularization, of bladder pain syndrome/interstitial cystitis (BPS/IC) and the response to intravesical therapy.

MATERIAL AND METHODS

We retrospectively evaluated cystoscopy findings in patients who had a preliminary diagnosis of BPS/IC. All patients received early intravesical combined therapy (ICT), ie, within 2 hours after hydrodistention. Additionally, ICT was continued according to our protocol. Cystoscopic findings were classified as glomerulations, hypervascularization, and Hunner's lesion (HL). The therapy responses were evaluated at 1st, 3rd, 6th, and 12thmonths using the visual analog scale (VAS), O'Leary/Sant interstitial cystitis symptom index (ICSI), and interstitial cystitis problem index (ICPI) scores.

RESULTS

Out of 61 patients, HL was diagnosed during cystoscopy in six (9.8%) patients, glomerulations in 35 (57.4%) patients, and hypervascularization in 15 (24.6%) patients. No pathological findings were defined in five (8.2%) patients. In the glomerulation and hypervascularization group, the median VAS, ICSI, and ICPI scores were lower than those in the preoperative period in the follow-up. In patients with HL, the median VAS scores were lower in the entire follow-up compared to the preoperative period, with an increase at 1st year compared to 6th month, and ICSI scores were lower than preoperative period in the entire follow-up, with an increase at 3rd month and 1st year. ICPI scores were also lower during the follow-up, with an increase observed in the 1st year.

CONCLUSION

The presence of hypervascularization should be defined since it might show different characteristics that may affect the ICT response. Patients with glomerulations might be good candidates for early combined intravesical therapy.

Effect of Force, Posture, and Repetitive Wrist Motion on Intraneural Blood Flow in the Median Nerve

OBJECTIVES

Pinching, deviated wrist postures, and repetitive motion are risk factors for carpal tunnel syndrome. Hypervascularization of the median nerve and increased intraneural blood flow proximal to the carpal tunnel result in finger force and deviated wrist postures. The purpose of this study was to determine the effects of pinching with and without force, wrist posture, and repetitive wrist motion on intraneural blood flow in the median nerve.

METHODS

Eleven healthy and 11 carpal tunnel syndrome-symptomatic individuals completed 3 sections of this study: 15 pinch posture force trials, 3 repetitive wrist motion trials, and 3 static wrist posture trials. Intraneural blood flow (centimeters per second) was measured with pulsed wave Doppler ultrasound during each trial. Transverse B-mode images obtained from static trials were used to calculate the median nerve cross-sectional area and circumference.

RESULTS

An analysis of variance statistical analysis revealed significant main effects of pinch posture force (F_4,80 = 21.397; P < .001) and wrist posture (F_2,40 = 14.545; P < .001). Intraneural blood flow velocities were significantly greater when 6 N of force was applied by the thumb, finger, or pinch compared to no applied force in the same postures. Intraneural blood flow velocities were higher at 30° wrist flexion (mean ± SD, 2.24 ± 0.42 cm/s) than neutral (2.06 ± 0.45 cm/s) and 30° wrist extension (1.97 ± 0.46 cm/s). No changes were found in response to repetitive wrist motion.

CONCLUSIONS

Flexed wrists as well as applied finger and thumb forces increase median nerve blood flow at the entry to the carpal tunnel, which may negatively affect the median nerve.

Hypervascularization in mTOR-dependent focal and global cortical malformations displays differential rapamycin sensitivity

OBJECTIVES

Patients with mammalian target of rapamycin (mTOR)-dependent malformations of cortical development (MCDs) associated with seizures display hyperperfusion and increased vessel density of the dysmorphic cortical tissue. Some studies have suggested that the vascular defect occurred independently of seizures. Here, we further examined whether hypervascularization occurs in animal models of global and focal MCD with and without seizures, and whether it is sensitive to the mTOR blocker, rapamycin, that is approved for epilepsy treatment in tuberous sclerosis complex.

METHODS

We used two experimental models of mTOR-dependent MCD consisting of conditional transgenic mice containing Tsc1^null cells in the forebrain generating a global malformation associated with seizures and of wild-type mice containing a focal malformation in the somatosensory cortex generated by in utero electroporation (IUE) that does not lead to seizures. Alterations in blood vessels and the effects of a 2-week-long rapamycin treatment on these phenotypes were assessed in juvenile mice.

RESULTS

Blood vessels in both the focal and global MCDs of postnatal day 14 mice displayed significant increase in vessel density, branching index, total vessel length, and decreased tissue lacunarity. In addition, rapamycin treatment (0.5 mg/kg, every 2 days) partially rescued vessel abnormalities in the focal MCD model, but it did not ameliorate the vessel abnormalities in the global MCD model that required higher rapamycin dosage for a partial rescue.

SIGNIFICANCE

Here, we identified hypervascularization in mTOR-dependent MCD in the absence of seizures in young mice, suggesting that increased angiogenesis occurs during development in parallel to alterations in corticogenesis. In addition, a predictive functional outcome is that dysplastic neurons forming MCD will have better access to oxygen and metabolic supplies via their closer proximity to blood vessels. Finally, the difference in rapamycin sensitivity between a focal and global MCD suggest that rapamycin treatment will need to be titrated to match the type of MCD.

Chemoresistance and the Self-Maintaining Tumor Microenvironment

The progression of cancer is associated with alterations in the tumor microenvironment, including changes in extracellular matrix (ECM) composition, matrix rigidity, hypervascularization, hypoxia, and paracrine factors. One key malignant phenotype of cancer cells is their ability to resist chemotherapeutics, and elements of the ECM can promote chemoresistance in cancer cells through a variety of signaling pathways, inducing changes in gene expression and protein activity that allow resistance. Furthermore, the ECM is maintained as an environment that facilitates chemoresistance, since its constitution modulates the phenotype of cancer-associated cells, which themselves affect the microenvironment. In this review, we discuss how the properties of the tumor microenvironment promote chemoresistance in cancer cells, and the interplay between these external stimuli. We focus on both the response of cancer cells to the external environment, as well as the maintenance of the external environment, and how a chemoresistant phenotype emerges from the complex signaling network present.

Superparamagnetic iron oxide-enhanced magnetic resonance imaging is useful in predicting malignant potential of vascular transformation of hypointense hypovascular nodules on gadoxetic acid-enhanced magnetic resonance imaging

AIM

To examine whether superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) can be used to assess the malignant potential of hepatic hypovascular nodules showing hypointensity during the hepatobiliary phase (HBP) on gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI.

METHODS

The study included 42 patients with chronic liver disease who had small hypovascular nodules (5-15 mm) showing hypointensity during the HBP on Gd-EOB-DTPA-enhanced MRI. The SPIO-enhanced T2-weighted MRI analyzed whether the signal intensity of each nodule was high. Nodules were prospectively followed up until hypervascularization by periodic Gd-EOB-DTPA-enhanced MRI. Initial MRI findings and clinical variables were used to analyze predictive factors for hypervascularization.

RESULTS

We analyzed 77 nodules, of which 19 (25%) showed hypervascularization during the observation period. The cumulative rates for hypervascularization were 11% and 22% at 1 and 2 years, respectively. Hyperintensity was observed in 12 nodules (16%) on SPIO-enhanced T2-weighted MRI; among these, 7 (58%) showed hypervascularization, whereas 12 (18%) of the remaining 65 nodules without hyperintensity showed hypervascularization (P = 0.007). A Cox model revealed that independent predictors of hypervascularization included hyperintense nodules on SPIO-enhanced MRI (P < 0.001). The cumulative rates for hypervascularization in hyperintense nodules on SPIO-enhanced MRI were 52% at 1 year, whereas these rates were 3% for non-hyperintense nodules.

CONCLUSION

Superparamagnetic iron oxide-enhanced MRI is useful for predicting the malignant potential of vascular transformation of hypovascular nodules with hypointensity observed in the HBP on Gd-EOB-DTPA-enhanced MRI.

Presence of non-hypervascular hypointense nodules on Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging in patients with hepatocellular carcinoma

BACKGROUND AND AIMS

Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) performed before curative therapy for hepatocellular carcinoma (HCC) can distinguish between intrahepatic distant recurrence and hypervascularization. This study aimed to retrospectively evaluate the presence of non-hypervascular hypointense nodules on hepatobiliary phase images from Gd-EOB-DTPA-enhanced MRI as a risk factor of the intrahepatic distant recurrence of early stage HCC following radiofrequency ablation (RFA).

METHODS

A total of 132 patients who underwent preprocedural Gd-EOB-DTPA-enhanced MRI followed by initial RFA were retrospectively analyzed. Post-RFA intrahepatic distant recurrence, which excluded the hypervascularization of non-hypervascular hypointense nodules detected by preprocedural Gd-EOB-DTPA-enhanced MRI, was evaluated according to the presence of non-hypervascular hypointense nodules on preprocedural Gd-EOB-DTPA-enhanced MRI.

RESULTS

Intrahepatic distant recurrence rates following RFA were higher in patients with non-hypervascular hypointense nodules (1-year: 22.5%, 2-year: 52.1%, 5-year: 89.1%) compared with in patients without non-hypervascular hypointense nodules (1-year: 7.0%, 2-year: 28.8%, 5-year: 48.7%). The presence of non-hypervascular hypointense nodules was associated with markedly increased cumulative recurrence rates of both identical and different subsegment intrahepatic distant recurrence, being an independent risk factor for post-RFA identical and different subsegment intrahepatic distant recurrence (identical: HR = 2.365, P = 0.027; different: HR = 3.276, P < 0.001).

CONCLUSION

The presence of non-hypervascular hypointense nodules on hepatobiliary phase images from Gd-EOB-DTPA-enhanced MRI obtained prior to RFA is an important predictive factor of intrahepatic distant recurrence following RFA of HCC.

Assessment of clinical and magnetic resonance imaging features of de novo hypervascular hepatocellular carcinoma using gadoxetic acid-enhanced magnetic resonance imaging

AIM

To clarify the clinical and magnetic resonance imaging (MRI) features of de novo hypervascular hepatocellular carcinoma (HCC) using serial gadoxetic acid-enhanced MRI.

METHODS

The institutional review board approved this retrospective study. After review of 1007 MRI examinations in 240 patients with chronic liver disease, 17 newly developed hypervascular HCCs in 16 patients detected by follow-up from initial MRI examination without hepatocellular nodules were evaluated. The clinical and MRI findings such as previous treatment history for HCC, period to hypervascular HCC onset, presence or absence of hypovascular hypointense nodules on hepatobiliary phase before hypervascularization, and intralesional fat component were recorded or evaluated. Statistical evaluations included Fisher's exact test, χ² -test, and Mann-Whitney U-test.

RESULTS

In 17 HCCs, 12 (71%) were de novo hypervascular HCC without showing hypovascular hypointense nodule on hepatobiliary phase before hypervascularization (de novo group) and 5 (29%) were hypervascularized HCC developed during multistep hepatocarcinogenesis (multistep group). The incidence of previous treatment history for HCC in the de novo group (91%) was significantly higher than that in the multistep group (20%) (P = 0.013). The duration to hypervascular HCC onset from initial examination was shorter in the de novo group (mean, 291 days) than in the multistep group (mean, 509 days) (P = 0.035). The incidence of fat-containing lesion in the de novo group (0%) was lower than that in the multistep group (40%) (P = 0.074).

CONCLUSION

De novo hypervascular HCC is characterized by rapid growth, patients with previous treatment history for HCC, and lack of intralesional fat, compared to hypervascular HCC with multistep progression.