Hyaline-vascular type unicentric Castleman disease with dysplastic follicular dendritic cell proliferative lesions: a case report

Castleman disease (CD) is a rare lymphoproliferative disease. Hyaline-vascular type unicentric CD has a good prognosis if completely resected during surgery. However, follicular dendritic cell proliferative lesions have the potential for recurrence and metastasis. A 22-year-old man was referred to our hospital with the chief complaint of nausea and vomiting. These symptoms were caused by a right mesocolonic tumor pushing the duodenum. The patient underwent laparoscopic tumorectomy and complete surgical excision. The postoperative course was uneventful, with no complications. Pathological examination confirmed that the tumor was an enlarged lymph node, typical of hyaline vascular-type CD; however, follicular dendritic cell proliferative lesions were noted. We report a rare case of hyaline-vascular-type CD with follicular dendritic cell proliferative lesions associated with malignancy, as limited case reports exist on this particular disease.

Chemical Bowel Preparation Exerts an Independent Preventive Effect Against Surgical Site Infection Following Elective Laparoscopic Colorectal Surgery

BACKGROUND

We investigated the independent clinical value of mechanical bowel preparations (MBP) and chemical bowel preparations (CBP) for preventing surgical site infection (SSI) in patients undergoing elective laparoscopic colorectal surgery.

MATERIALS AND METHODS

This retrospective cohort study included 475 patients who underwent elective laparoscopic colorectal surgery between January 2018 and March 2022. CBP was introduced in January 2021 and included kanamycin (1 g) and metronidazole (1 g) 2 times a day, the day before surgery. In some cases, MBP was omitted in patients who planned to undergo right-sided colectomy, those with tumor obstruction, and those with poor general conditions, depending on the judgment of the physician. The primary endpoint was the overall SSI incidence, while the secondary endpoints were the incidences of incisional SSI and organ-space SSI, culture from the surgical site, and length of postoperative hospital stay.

RESULTS

In total, 136 patients underwent CBP. MBP was omitted in 53 patients. Overall, SSI occurred in 80 patients (16.8%), including 61 cases of incisional SSI (12.8%) and 36 cases of organ-space SSI (7.6%). Multivariate logistic regression revealed that CBP exerted an independent preventive effect on overall and incisional SSI, whereas MBP did not. However, CBP was not associated with a decreased risk of overall SSI in patients who had undergone preoperative therapy, those with benign disease, and those with stoma formation in the subgroup analysis. Levels of Bacteroides species at the surgical site were significantly lower in the CBP group than in the non-CBP group. Postoperative hospital stay was significantly longer in the incisional SSI group than in the non-SSI group and was significantly longer in the organ-space SSI group than in the other groups.

CONCLUSIONS

CBP, but not MBP, exerts an independent preventive effect on SSI, especially incisional SSI, in patients undergoing elective laparoscopic colorectal surgery.

Visualization of Anorectal Lymphatic Flow Using Indocyanine Green Fluorescence Imaging: An Observational Study

BACKGROUND/AIM

Currently, only a small part of functional lymphatic flow around the anorectal region has been anatomically analyzed. Despite the fact that local recurrence is often experienced in the pelvic floor, the functional lymphatic network in this region has rarely been studied due to difficulties in observation. This prospective observational study aimed to observe anorectal lymphatic flow around the pelvic floor using intraoperative indocyanine green fluorescence imaging during laparoscopic or robot-assisted rectal surgery.

PATIENTS AND METHODS

Fourteen patients who underwent laparoscopic (n=7) or robot-assisted (n=7) surgery without any preoperative therapy between April and December 2022 were enrolled. Indocyanine green solution (0.25 mg) was injected into the submucosa at the dentate line of the anterior, posterior, and bilateral walls prior to surgery. During and after total mesorectal excision, lymphatic flow was observed using a near-infrared camera system.

RESULTS

Lymphatic flow visualized by indocyanine green was detected not only in the already-known route from the low rectum to the lateral pelvic lymph nodes via the lateral ligament, but also in the novel route from the low rectum to the surface of the levator ani muscle and hiatal ligament. Fluorescence was widely spread in the pelvic floor between the longitudinal muscle of the low rectum and the surface of the levator ani muscle.

CONCLUSION

Even though the results are preliminary since histological analyses were not performed, a novel widespread lymphatic network on the surface of the levator ani muscle originating from the longitudinal muscle fibers of the low rectum was revealed.

Search for the Majorana Nature of Neutrinos in the Inverted Mass Ordering Region with KamLAND-Zen

The KamLAND-Zen experiment has provided stringent constraints on the neutrinoless double-beta (0νββ) decay half-life in ^{136}Xe using a xenon-loaded liquid scintillator. We report an improved search using an upgraded detector with almost double the amount of xenon and an ultralow radioactivity container, corresponding to an exposure of 970 kg yr of ^{136}Xe. These new data provide valuable insight into backgrounds, especially from cosmic muon spallation of xenon, and have required the use of novel background rejection techniques. We obtain a lower limit for the 0νββ decay half-life of T_{1/2}^{0ν}>2.3×10^{26}  yr at 90% C.L., corresponding to upper limits on the effective Majorana neutrino mass of 36-156 meV using commonly adopted nuclear matrix element calculations.

Short- and long-term outcomes of preservation versus ligation of the inferior mesenteric artery in laparoscopic D3 lymph node dissection for descending colon cancer: a propensity score-matched analysis

PURPOSE

This study aimed to compare the short- and long-term outcomes of laparoscopic D3 lymph node (LN) dissection between ligation of the inferior mesenteric artery (IMA) (LIMA) and preservation of the IMA (PIMA) for descending colon cancer using propensity score-matched analysis.

METHODS

This retrospective study included 101 patients with stage I-III descending colon cancer who underwent laparoscopic D3 LN dissection with LIMA (n = 60) or PIMA (n = 41) at a single center between January 2005 and March 2022. After propensity score matching, 64 patients (LIMA, n = 32; PIMA, n = 32) were included in the analysis. The primary endpoint was the long-term outcomes, and the secondary endpoint was the surgical outcomes.

RESULTS

In the matched cohort, no significant difference was noted in the surgical outcomes, including the operative time, estimated blood loss, number of harvested LNs, number of harvested LN 253, and complication rate. The long-term outcomes were also not significantly different between the LIMA and PIMA groups (3-year recurrence-free survival, 72.2% vs. 75.6%, P = 0.862; 5-year overall survival, 69.8% vs. 63.4%, P = 0.888; 5-year cancer-specific survival, 84.2% vs. 82.8%, P = 0.607). No recurrence of LN metastasis was observed around the IMA root.

CONCLUSION

Laparoscopic D3 dissection in PIMA was comparable to that in LIMA regarding both short- and long-term outcomes. The optimal LN dissection for descending colon cancer should be investigated in future large-scale studies.

Comparison of Short-term Outcomes of a Self-expandable Metallic Stent as a Bridge to Laparoscopic Surgery between Right- and Left-sided Obstructive Colorectal Cancers: A Retrospective Observational Study

OBJECTIVES

Few studies have compared the tumor-site-based postoperative short-term outcomes of a bridge to surgery using self-expandable metallic stents. This study compared the perioperative outcomes following stent placement between right- and left-sided obstructive colorectal cancers, focusing on patients undergoing laparoscopic surgery.

METHODS

This study included 127 patients with stage I-IV obstructive colorectal cancer (right-sided, n = 25 [19.7%]; left-sided, n = 102 [80.3%]) who underwent laparoscopic-assisted surgery following stent placement between May 2012 and September 2021. We compared the postoperative complication rates and the success rates of stent placement.

RESULTS

The clinical success rate was not significantly different (92% vs. 97.1%, P = 0.254). The rates of all-grade complications (36% vs. 16.7%, P = 0.05) and postoperative ileus or small-bowel obstruction (20% vs. 2%, P = 0.003) were significantly higher in the right-sided group. The rates of the Clavien-Dindo classification ≥ III complications (8% vs. 6.9%, P = 1) and the median durations of postoperative hospital stay (8 days vs. 8 days, P = 1) were not significantly different. On multivariate analysis, right-sided colon cancer was an independent risk factor for postoperative ileus or small-bowel obstruction (odds ratio [OR]: 16.5, 95% confidence interval [CI]: 2.42-112, P = 0.004) but not for all grades of complications (OR: 2.63, 95% CI: 0.976-7.09, P = 0.056).

CONCLUSIONS

Although the rates of clinical success, postoperative Clavien-Dindo classification ≥ III severe complications, and postoperative hospital stay were comparable, the bridge to surgery following stent placement for right-sided obstructive colon cancer raises concerns about ileus or small-bowel obstruction.

Postoperative colon perforation due to the tip of the transanal decompression tube after laparoscopic low anterior resection: A case report

A 66-year-old man underwent laparoscopic low anterior resection for rectal cancer. A transanal decompression tube (24Fr Nelaton catheter) was placed laparoscopically during the surgery. Contrast enema on postoperative day 5 showed perforation of the sigmoid colon around the tip of the tube, and emergency laparotomy was performed. Perforation of the posterior sigmoid colon located on the proximal side of the colorectal anastomosis at the level of the promontorium was identified. Closure of the perforation site, lavage drainage, and a diverting loop ileostomy were performed. Although a transanal decompression tube is useful in preventing anastomotic leakage, tube-related colon perforation should be noted, and controversies about the safety of laparoscopically transanal decompression tube placement should be resolved. Adequate management for tube placement should be discussed.

Short-term outcomes of extracorporeal colo-colonic triangular anastomosis versus functional end-to-end anastomosis in laparoscopic-assisted surgery for left-sided colon cancer: a propensity score matching analysis

PURPOSE

To the best of our knowledge, no studies have compared the short-term outcomes between colo-colonic extracorporeal triangular anastomosis (TA) and functional end-to-end anastomosis (FEEA), with a focus on laparoscopic-assisted surgery for left-sided colon cancer. Therefore, this study compared the short-term outcomes of these anastomoses using propensity score matching analysis.

METHODS

This retrospective study included 129 patients with stage I-IV left-sided colon cancer who underwent laparoscopic-assisted surgery with colo-colonic extracorporeal TA (n = 75) or FEEA (n = 54) between May 2009 and March 2021. After propensity score matching, 84 patients (TA, n = 42; FEEA, n = 42) were included in the analysis. The primary endpoint was the complication rate for all grades, and the secondary endpoints were the rates of Clavien - Dindo grade ≥ 3 complications and anastomotic leakage.

RESULTS

In the matched cohort, there were no significant differences in the complication rates for all grades (35.7% vs. 26.2%, p = 0.479), Clavien - Dindo grade ≥ 3 complications (11.9% vs. 11.9%, p = 1), and anastomotic leakage (0% vs. 4.8%, p = 0.494) between the TA and FEEA groups. In the univariate logistic regression analysis, TA did not increase the frequency of complications for any grades compared with FEEA (odds ratio: 1.570, 95% confidence interval: 0.616-3.980, p = 0.347).

CONCLUSION

Extracorporeal TA demonstrated equivalent short-term outcomes compared with FEEA in cases of laparoscopic-assisted surgery for left-sided colon cancer. TA can be an alternative anastomosis technique in cases wherein FEEA is difficult to perform.

Repeated Resection for Recurrent Metastatic Solid Pseudopapillary Neoplasm of the Pancreas

Patient: Female, 49-year-old

Final Diagnosis: Solid pseudopapillary neoplasm

Symptoms: Jaundice and right upper abdominal pain

Medication:—

Clinical Procedure: —

Specialty: Pathology • Surgery

Intratumoural immune cell landscape in germinoma reveals multipotent lineages and exhibits prognostic significance

AIMS

Alterations in microenvironments are a hallmark of cancer, and these alterations in germinomas are of particular significance. Germinoma, the most common subtype of central nervous system germ cell tumours, often exhibits massive immune cell infiltration intermingled with tumour cells. The role of these immune cells in germinoma, however, remains unknown.

METHODS

We investigated the cellular constituents of immune microenvironments and their clinical impacts on prognosis in 100 germinoma cases.

RESULTS

Patients with germinomas lower in tumour cell content (i.e. higher immune cell infiltration) had a significantly longer progression-free survival time than those with higher tumour cell contents (P = 0.03). Transcriptome analyses and RNA in-situ hybridization indicated that infiltrating immune cells comprised a wide variety of cell types, including lymphocytes and myelocyte-lineage cells. High expression of CD4 was significantly associated with good prognosis, whereas elevated nitric oxide synthase 2 was associated with poor prognosis. PD1 (PDCD1) was expressed by immune cells present in most germinomas (93.8%), and PD-L1 (CD274) expression was found in tumour cells in the majority of germinomas examined (73.5%).

CONCLUSIONS

The collective data strongly suggest that infiltrating immune cells play an important role in predicting treatment response. Further investigation should lead to additional categorization of germinoma to safely reduce treatment intensity depending on tumour/immune cell balance and to develop possible future immunotherapies.

Measurement of neutral gas pressure in the D-module of GAMMA 10/PDX by using ASDEX type fast ionization gauge

In the divertor simulation experiments in the GAMMA 10/PDX tandem mirror, pressure of the neutral gas was investigated by using a fast ionization gauge. The gauge was absolutely calibrated for hydrogen gas by using a capacitance manometer. Change of the gauge sensitivity due to the magnetic field of GAMMA 10/PDX was also evaluated. The typical gas pressure measured in detached plasma experiments was 0.1-10 Pa. The degree of plasma detachment determined from the reduction of heat flux was enhanced as the gas pressure increases. Rapid increase of the gas pressure under the plasma flow was also observed.

Recurrent mutations of CD79B and MYD88 are the hallmark of primary central nervous system lymphomas

AIMS

Primary central nervous system lymphoma (PCNSL) manifest aggressive clinical behaviour and have poor prognosis. Although constitutive activation of the nuclear factor-κB (NF-κB) pathway has been documented, knowledge about the genetic alterations leading to the impairment of the NF-κB pathway in PCNSLs is still limited. This study was aimed to unravel the underlying genetic profiles of PCNSL.

METHODS

We conducted the systematic sequencing of 21 genes relevant to the NF-κB signalling network for 71 PCNSLs as well as the pyrosequencing of CD79B and MYD88 mutation hotspots in a further 35 PCNSLs and 46 glioblastomas (GBMs) for validation.

RESULTS

The results showed that 68 out of 71 PCNSLs had mutations in the NF-κB gene network, most commonly affecting CD79B (83%), MYD88 (76%), TBL1XR1 (23%), PRDM1 (20%) and CREBBP1 (20%). These mutations, particularly CD79B and MYD88, frequently coincided within each tumour in various combinations, simultaneously affecting diverse pathways within the network. No GBMs had hotspot mutation of CD79B Y196 and MYD88 L265.

CONCLUSIONS

The prevalence of CD79B and MYD88 mutations in PCNSLs was considerably higher than reported in systemic diffuse large B-cell lymphomas. This observation could reflect the paucity of antigen stimuli from the immune system in the central nervous system (CNS) and the necessity to substitute them by the constitutive activation of CD79B and MYD88 that would initiate the signalling cascades. These hotspot mutations may serve as a genetic hallmark for PCNSL serving as a genetic marker for diagnose and potential targets for molecular therapy.

Search for bosonic superweakly interacting massive dark matter particles with the XMASS-I detector

Bosonic superweakly interacting massive particles (super-WIMPs) are a candidate for warm dark matter. With the absorption of such a boson by a xenon atom, these dark matter candidates would deposit an energy equivalent to their rest mass in the detector. This is the first direct detection experiment exploring the vector super-WIMPs in the mass range between 40 and 120 keV. With the use of 165.9 day of data, no significant excess above background was observed in the fiducial mass of 41 kg. The present limit for the vector super-WIMPs excludes the possibility that such particles constitute all of dark matter. The absence of a signal also provides the most stringent direct constraint on the coupling constant of pseudoscalar super-WIMPs to electrons. The unprecedented sensitivity was achieved exploiting the low background at a level 10(-4)  kg-1 keVee-1 day-1 in the detector.