Narrow band imaging-guided endoscopic biopsy for intraventricular and paraventricular brain tumors: clinical experience with 14 cases

Background

Narrow-band imaging (NBI) has been confirmed as a useful endoscopic technique to distinguish neoplasm from normal tissue, on the basis of the enhanced neovascularity of tumor tissue. NBI-guided tissue biopsy for laryngopharyngeal and digestive lesions is a novel methodology, but the feasibility for central nervous system tumors remains unclear. The aim of our study was to evaluate the feasibility of NBI-guided biopsy for intraventricular and paraventricular tumor.

Methods

Fourteen patients with intraventricular or paraventricular tumors underwent neuroendoscopic biopsy using a videoscope with NBI. Ventricular walls and tumors were observed using conventional imaging, followed by NBI. Colors of ventricle walls and tumors visualized using NBI were compared to those visualized under conventional imaging. Extracted specimens were stained using CD31 antibody and numbers of microvessels in each specimen were counted for analyzing vascular density.

Results

Normal ventricle walls were a similar color under conventional imaging and NBI. Tumor surfaces appeared to be cyan in color under NBI. Vessels on the tumor were more clearly visualized with NBI than with conventional imaging. NBI was able to identify tumor surfaces that were not perceptible on conventional imaging. All specimens in the lesion surfaces from cyan-colored areas under NBI contained tumor cells. Specimens extracted from regions that appeared cyan in color under NBI (51.0 vessels/mm²) had significantly greater vascular density than regions that appeared a normal color (17.4 vessels/mm²; p = 0.039).

Conclusion

NBI-guided biopsy of intraventricular and paraventricular tumors is feasible for visualizing tumor surface-enhancing neovascularities. NBI would contribute to accurate histological diagnosis while minimizing injury to surrounding structures.     

Clinical importance of impingement deformities for hip osteoarthritis progression in a Japanese population

Purpose

Femoroacetabular impingement is a new disease concept for hip disorders in young adults suggested as a major cause of primary hip osteoarthritis in Western countries. However, significant controversy exists regarding the prevalence and contribution of impingement deformities to osteoarthritis in Japan, owing to the higher prevalence of developmental dysplasia of the hip. Therefore, the aims of this study were to: (1) determine the prevalence of structural abnormalities associated with hip disorders in patients undergoing total hip replacement and (2) analyse the contribution of impingement deformities to osteoarthritis.

Methods

We analysed 250 patients from two different medical centres who underwent primary total hip replacement except those which were due to femoral head necrosis, posttraumatic osteoarthritis and systemic inflammatory disease. The average patient age at surgery was 64 years (range, 40–89 years), with 35 men and 215 women.

Results

Radiographic abnormality related to developmental dysplasia of the hip was associated with the majority of osteoarthritic hips (62 %). Hips with femoroacetabular impingement deformities were present within the cases categorized as unknown etiology. Cam impingement deformity was present in 22 % of unknown aetiology cases when cases with reactive osteophytes were excluded from all cam deformity cases (pistol grip deformity and aspherical femoral heads).

Conclusions

The prevalence of femoroacetabular impingement within primary osteoarthritis cases and gender predominance of impingement deformities are relatively similar to those reported previously in Western populations. This finding indicates that femoroacetabular impingement deformities are associated with osteoarthritis in the Japanese population, although it has a lower frequency among all hip failure patients.     

Induction of hibernation-like hypothermia by central activation of the A1 adenosine receptor in a non-hibernator,the rat

Central adenosine A1-receptor (A1AR)-mediated signals play a role in the induction of hibernation. We determined whether activation of the central A1AR enables rats to maintain normal sinus rhythm even after their body temperature has decreased to less than 20 °C. Intracerebroventricular injection of an adenosine A1 agonist, N6-cyclohexyladenosine (CHA), followed by cooling decreased the body temperature of rats to less than 20 °C. Normal sinus rhythm was fundamentally maintained during the extreme hypothermia. In contrast, forced induction of hypothermia by cooling anesthetized rats caused cardiac arrest. Additional administration of pentobarbital to rats in which hypothermia was induced by CHA also caused cardiac arrest, suggesting that the operation of some beneficial mechanisms that are not activated under anesthesia may be essential to keep heart beat under the hypothermia. These results suggest that central A1AR-mediated signals in the absence of anesthetics would provide an appropriate condition for maintaining normal sinus rhythm during extreme hypothermia.     

Suture Granuloma With False-Positive Findings on FDG-PET/CT Resected via Laparoscopic Surgery

A 61-year-old woman who had undergone total hysterectomy 16 years previously exhibited a pelvic tumor on computed tomography (CT). F-18 fluorodeoxyglucose (FDG) combined positron emission tomography (PET)/CT imaging revealed a solitary small focus of increased FDG activity in the pelvis. A gastrointestinal stromal tumor originating in the small intestine or another type of tumor originating in the mesentery (desmoid, schwannoma, or foreign body granuloma) was suspected; therefore, laparoscopic resection was conducted. A white, hard tumor was found to originate from the mesentery of the sigmoid colon and adhered slightly to the small intestine. The tumor was resected with a negative margin, and the pathologic diagnosis was suture granuloma. The possibility of suture granuloma should be kept in mind in cases of tumors with positive PET findings and a history of surgery close to the lesion. However, it is difficult to preoperatively diagnose pelvic tumors using a biopsy. Therefore, considering the possibility of malignancy, it is necessary to achieve complete resection without exposing the tumor.Key words: Suture granuloma, Laparoscopy, Positron emission tomography (PET)It is very difficult to diagnose suture granulomas preoperatively. F-18 fluorodeoxyglucose (FDG) combined positron emission tomography (PET)/computed tomography (CT) imaging is often used to differentiate benign from malignant tumors that are difficult to diagnose on other modalities, such as ultrasound (US), CT, and magnetic resonance imaging. However, it is not easy to differentiate tumors associated with inflammation or malignancy using FDG-PET/CT. Suture granulomas are known to be benign; however, false-positive findings were observed on PET/CT in our case. In the literature, there are few reports of suture granulomas showing false-positive findings on PET/CT.^1–5 We report here a case in which it was not possible to rule out the potential for malignancy using CT or FDG-PET/CT and the lesion was confirmed to be a suture granuloma based on a pathologic examination following laparoscopic resection.