Angpt1 binding to Tie1 regulates the signaling required for lymphatic vessel development in zebrafish.

Development of the vascular system is regulated by multiple signaling pathways mediated by receptor tyrosine kinases. Among them, angiopoietin (Ang)/Tie signaling regulates lymphatic and blood vessel development in mammals. Of the two Tie receptors, Tie2 is well known as a key mediator of Ang/Tie signaling, but, unexpectedly, recent studies have revealed that the Tie2 locus has been lost in many vertebrate species, whereas the Tie1 gene is more commonly present. However, Tie1-driven signaling pathways, including ligands and cellular functions, are not well understood. Here, we performed comprehensive mutant analyses of angiopoietins and Tie receptors in zebrafish and found that only angpt1 and tie1 mutants show defects in trunk lymphatic vessel development. Among zebrafish angiopoietins, only Angpt1 binds to Tie1 as a ligand. We indirectly monitored Ang1/Tie1 signaling and detected Tie1 activation in sprouting endothelial cells, where Tie1 inhibits nuclear import of EGFP-Foxo1a. Angpt1/Tie1 signaling functions in endothelial cell migration and proliferation, and in lymphatic specification during early lymphangiogenesis, at least in part by modulating Vegfc/Vegfr3 signaling. Thus, we show that Angpt1/Tie1 signaling constitutes an essential signaling pathway for lymphatic development in zebrafish.

Long-term survival and functional outcomes of laparoscopic surgery for clinical stage I ultra-low rectal cancers located within 5 cm of the anal verge: A prospective phase II trial (Ultimate trial).

OBJECTIVE: To clarify the long-term oncological outcomes and postoperative anal, urinary, and sexual functions after laparoscopic surgery for clinical stage I very low rectal carcinoma located near the anal canal. SUMMARY BACKGROUND DATA: Laparoscopic surgery is widely applied for rectal cancer; however, concerns remain, with some studies showing poorer outcomes compared to open surgery. METHODS: This single-arm, phase II trial included patients registered preoperatively from 47 institutions in Japan. The planned sample size was 300. The primary endpoint was the 3-year local recurrence rate. Anal, urinary, and sexual functions were evaluated using a prospective questionnaire. RESULTS: Three-hundred patients were registered between January 2014 and March 2017. Anus-preserving surgery was performed in 278 (93%), including 172 who underwent intersphincteric resection (58%) and 106 (36%) who underwent low anterior resection. The 3-year cumulative local recurrence rate was 6.3%. At 3 years postoperatively, 87% of patients used their own anus, and the median incontinence score improved from 12 at 3 months to 8 at 3 years. Only 5% of patients had severe incontinence (incontinence score of 16 points). Postoperative urinary function evaluation showed that International Prostate Symptom Score and Overactive Bladder Symptom Score decreased 1 week after surgery, but recovered to preoperative level 1 month after surgery. International Consultation on Incontinence Questionnaire-Sort Form remained almost stable after surgery. Sexual function evaluation using the International Index of Erectile Function-5 and International Index of Erectile Function-15 revealed that the patients had deteriorated 3 months after surgery but had recovered only slightly by 6 months. CONCLUSIONS: Laparoscopic surgery achieves feasible long-term oncological outcomes and a high rate of anus preservation with moderate anal function, and an acceptable incontinence score. While urinary function recovered rapidly, sexual function showed poor recovery.

Clinical Impact of Skeletal Muscle Mass and Nutritional Status in Patients with Recurrent or Advanced Gastric Cancer Treated with Nivolumab.

INTRODUCTION: This study aimed to evaluate the clinical impact of skeletal muscle mass and nutritional status in gastric cancer patients treated with nivolumab monotherapy as late-line treatment. METHODS: We conducted a multi-institutional retrospective study of 90 gastric cancer patients who previously received anti-PD-1 therapy (nivolumab). On computed tomography images captured before nivolumab induction, the skeletal muscle index (SMI, cm2/m2) was defined as the erector muscle area (cm2) divided by the height (m) squared. Patients were divided into two groups: those with SMI-high (n = 45) and those with SMI-low (n = 45). Prognostic nutritional index (PNI) was also calculated before nivolumab induction. The associations of SMI and PNI with response rate (RR), progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and safety were analyzed. RESULTS: The cutoff values for SMI were determined as 13.45 for males and 10.41 for females. SMI-high was significantly associated with a higher RR (odds ratio = 12.36, p = 0.02) and DCR (odds ratio = 2.97, p = 0.02). Although not significant, PNI-high also tended to be associated with a higher RR. Multivariate analysis showed that SMI-high was independently associated with a higher RR and higher DCR in gastric cancer. Moreover, prognostic analyses revealed that SMI-high (log-rank test p = 0.008) and PNI-high (log-rank test p = 0.0008) were significantly associated with longer OS since nivolumab induction. SMI-high was also associated with longer PFS (log-rank test p = 0.03). There were no significant differences in immune-related adverse event between SMI-low and SMI-high. CONCLUSION: SMI and PNI were associated with nivolumab efficacy in gastric cancer patients. Management of skeletal muscle loss and nutritional status in gastric cancer patients who will receive nivolumab would be beneficial to enhance survival outcomes.

A molecular atlas of cell types and zonation in the brain vasculature.

Cerebrovascular disease is the third most common cause of death in developed countries, but our understanding of the cells that compose the cerebral vasculature is limited. Here, using vascular single-cell transcriptomics, we provide molecular definitions for the principal types of blood vascular and vessel-associated cells in the adult mouse brain. We uncover the transcriptional basis of the gradual phenotypic change (zonation) along the arteriovenous axis and reveal unexpected cell type differences: a seamless continuum for endothelial cells versus a punctuated continuum for mural cells. We also provide insight into pericyte organotypicity and define a population of perivascular fibroblast-like cells that are present on all vessel types except capillaries. Our work illustrates the power of single-cell transcriptomics to decode the higher organizational principles of a tissue and may provide the initial chapter in a molecular encyclopaedia of the mammalian vasculature.

Author Correction: A molecular atlas of cell types and zonation in the brain vasculature.

In Fig. 1b of this Article, 'Csf1r' was misspelt 'Csfr1'. In addition, in Extended Data Fig. 11b, owing to an error during figure formatting, the genes listed in the first column shifted down three rows below the first gene on the list, causing a mismatch between the gene names and their characteristics. These errors have been corrected online, and the original Extended Data Fig. 11b is provided as Supplementary Information to the accompanying Amendment.

Predictive risk factors for resection surface-related complications after laparoscopic simultaneous resection of primary colorectal tumor and synchronous liver metastases: a single-center retrospective study.

BACKGROUND: Laparoscopic simultaneous resection (LSR) of primary colorectal tumors and synchronous colorectal liver metastases (sCRLM) has been recently performed. This study aimed to evaluate the postoperative outcomes after LSR and determine the risk factors for resection surface-related complications (RSRC), such as postoperative biliary fistula and liver-transection surface abscess. METHODS: Between 2009 and 2022, consecutive patients with sCRLM who underwent LSR were included. We retrospectively analyzed clinicopathological data, including intraoperative factors and postoperative outcomes. The difficulty level of all liver resections was classified according to the IWATE difficulty scoring system (DSS). We then performed univariate and multivariate analyses to identify the risk factors for RSRC. RESULTS: Of the 112 patients, 94 (83.9%) underwent partial hepatectomy and colorectal surgery. The median DSS score was 5 points (1-11), with 12 (10.7%) patients scoring ≥ 7 points. Postoperative complications were observed in 41 (36.6%) patients, of whom 16 (14.3%) experienced severe complications classified as Clavien-Dindo grade IIIa or higher. There was no postoperative mortality. The most common complication was RSRC (19 patients, 17.0%). Multivariate analysis identified American Society of Anesthesiologists (ASA) classification ≥ 3 [odds ratio (OR) 10.3, 95% confidence interval (CI) 1.37-77.8; P = 0.023], DSS score ≥ 7 points (OR 5.08, 95% CI 1.17-20.0; P = 0.030), and right-sided colectomy (OR 4.67, 95% CI 1.46-15.0; P = 0.009) as independent risk factors for RSRC. Postoperative hospital stays were significantly longer for patients with RSRC than for those without RSRC (22 days vs. 11 days; P < 0.001). CONCLUSION: Short-term outcomes of LSR for patients with sCRLM were acceptable in an experienced center. RSRC was the most common complication, and high-difficulty hepatectomy, right-sided colectomy, and ASA classification ≥ 3 were independent risk factors for RSRC.

Field experiment of a telesurgery system using a surgical robot with haptic feedback.

PURPOSE: To verify the usefulness of haptic feedback in telesurgery and improve the safety of telerobotic surgery. METHODS: The surgeon's console was installed at two sites (Fukuoka and Beppu; 140 km apart), and the patient cart was installed in Fukuoka. During the experiment, the surgeon was blinded to the haptic feedback levels and asked to grasp the intestinal tract in an animal model. The surgeon then performed the tasks at each location. RESULTS: No marked differences in task accuracy or average grasping force were observed between the surgeon locations. However, the average task completion time was significantly longer, and the system usability scale (SUS) was significantly lower rating for remote operations than for local ones. No marked differences in task accuracy or task completion time were observed between the haptic feedback levels. However, with haptic feedback, the organ was grasped with a significantly weaker force than that without it. Furthermore, with haptic feedback, experienced surgeons in robotic surgery tended to perform an equivalent task with weaker grasping forces than inexperienced surgeons. CONCLUSION: The haptic feedback function is a tool that allows the surgeon to perform surgery with an appropriate grasping force, both on site and remotely. Improved safety is necessary in telesurgery; haptic feedback will thus be an essential technology in robotic telesurgery going forward.

Mutational spectrum of TP53 gene correlates with nivolumab treatment efficacy in advanced gastric cancer (TP53MUT study).

BACKGROUND: Although nivolumab has a high efficacy, reliable biomarkers are needed to predict the efficacy. We evaluated the nivolumab efficacy according to the TP53 mutation in advanced gastric cancer patients enrolled in the GI-SCREEN project. METHODS: Sequence data of tumour specimens and clinicopathological information of 913 patients with advanced gastric cancer who were enrolled between April 2015 and March 2017 were obtained from the GI-SCREEN database. The follow-up information of 266 patients treated with nivolumab was also provided. RESULTS: Among 266 patients treated with nivolumab, the objective response rate (ORR) of TP53 wild type (wt) patients (24.6%) was higher than that of TP53 mutant patients (14.8%). Among TP53 mutant patients, the ORR of the frameshift type tended to be higher than the transition and transversion type (23.1%, 13.6%, and 13.0%, respectively). The median progression-free survival (PFS) was statistically longer in TP53 wt patients than in mutant patients (3.3 vs 2.1 months, HR 1.4, 95% CI 1.1-1.9). Among TP53 mutant patients, PFS was statistically longer in the frameshift type than in the transversion type. CONCLUSION: Nivolumab showed better efficacy in TP53 wt patients than in mutant patients. Among TP53 mutant patients, the frameshift type may have efficacy from nivolumab treatment.

Immunoreactivity to WT1 peptide vaccine is associated with prognosis in elderly patients with acute myeloid leukemia: follow-up study of randomized phase II trial of OCV-501, an HLA class II-binding WT1 polypeptide.

We previously conducted a randomized phase II trial of OCV-501, a WT1 peptide presented by helper T cells, in elderly AML (acute myeloid leukemia) patients in first remission, indicating no difference in 2-year disease-free survival (DSF) between the OCV-501 and placebo groups. Here, we analyzed 5-year outcome and biomarkers. Five-year DFS was 36.0% in the OCV-501 group (N = 52) and 33.7% in the placebo group (N = 53), with no significant difference (p = 0.74). The peripheral WT1 mRNA levels were marginally suppressed in the OCV-501 group compared with the placebo group. Enhanced anti-OCV-501 IgG response by the 25th week was an independent favorable prognostic factor. Anti-OCV-501 IFNγ responses were less frequent than the IgG reactions. These findings suggest that host immunoreactivity has a significant impact on the prognosis of AML and that further improvement of the WT1 peptide vaccine is needed.

Artificial Intelligence-Based Prediction of Recurrence after Curative Resection for Colorectal Cancer from Digital Pathological Images.

BACKGROUND: To develop an artificial intelligence-based model to predict recurrence after curative resection for stage I-III colorectal cancer from digitized pathological slides. PATIENTS AND METHODS: In this retrospective study, 471 consecutive patients who underwent curative resection for stage I-III colorectal cancer at our institution from 2004 to 2015 were enrolled, and 512 randomly selected tiles from digitally scanned images of hematoxylin and eosin-stained tumor tissue sections were used to train a convolutional neural network. Five-fold cross-validation was used to validate the model. The association between recurrence and the model's output scores were analyzed in the test cohorts. RESULTS: The area under the receiver operating characteristic curve of the cross-validation was 0.7245 [95% confidence interval (CI) 0.6707-0.7783; P < 0.0001]. The score successfully classified patients into those with better and worse recurrence free survival (P < 0.0001). Multivariate analysis revealed that a high score was significantly associated with worse recurrence free survival [odds ratio (OR) 1.857; 95% CI 1.248-2.805; P = 0.0021], which was independent from other predictive factors: male sex (P = 0.0238), rectal cancer (P = 0.0396), preoperative abnormal carcinoembryonic antigen (CEA) level (P = 0.0216), pathological T3/T4 stage (P = 0.0162), and pathological positive lymph node metastasis (P < 0.0001). CONCLUSIONS: The artificial intelligence-based prediction model discriminated patients with a high risk of recurrence. This approach could help decision-makers consider the benefits of adjuvant chemotherapy.

Telesurgery and telesurgical support using a double-surgeon cockpit system allowing manipulation from two locations.

BACKGROUND: Although several studies on telesurgery have been reported globally, a clinically applicable technique has not yet been developed. As part of a telesurgical study series conducted by the Japan Surgical Society, this study describes the first application of a double-surgeon cockpit system to telesurgery. METHODS: Surgeon cockpits were installed at a local site and a remote site 140 km away. Three healthy pigs weighing between 26 and 29 kg were selected for surgery. Non-specialized surgeons performed emergency hemostasis, cholecystectomy, and renal vein ligation with remote assistance using the double-surgeon cockpits and specialized surgeons performed actual telesurgery. Additionally, the impact of adding internet protocol security (IPsec) encryption to the internet protocol-virtual private network (IP-VPN) line on communication was evaluated to address clinical security concerns. RESULTS: The average time required for remote emergency hemostasis with the double-surgeon cockpit system was 10.64 s. A non-specialized surgeon could safely perform cholecystectomy or renal vein ligation with remote assistance. Global Evaluative Assessment of Robotic Skills and System Usability Scale scores were higher for telesurgical support-assisted surgery by a non-specialized surgeon using the double-surgeon cockpits than for telesurgery performed by a specialized surgeon without the double-cockpit system. Adding IPsec encryption to the IP-VPN did not have a significant impact on communication. CONCLUSION: Telesurgical support through our double-surgeon cockpit system is feasible as first step toward clinical telesurgery.

Lineage of drug discovery research on fluorinated pyrimidines: chronicle of the achievements accomplished by Professor Setsuro Fujii.

Prof. Setsuro Fujii achieved significant results in the field of drug discovery research in Japan. He developed nine well-known drugs: FT, UFT, S-1 and FTD/TPI are anticancer drugs, while cetraxate hydrochloride, camostat mesilate, nafamostat mesilate, gabexate mesilate and pravastatin sodium are therapeutic drugs for various other diseases. He delivered hope to patients with various diseases across the world to improve their condition. Even now, drug discovery research based on Dr. Fujii's ideas is continuing.

[Methotrexate-related lymphoproliferative disease showing different histological findings at recurrence].

A 55-year old female patient was treated with methotrexate (MTX) and infliximab (IFX) for rheumatoid arthritis (RA). She experienced unknown fever, generalized lymphadenopathy, and liver tumors. Histological examination of the inguinal lymph node and a liver tumor resulted in the pathological diagnosis of classic Hodgkin lymphoma, with many Reed-Sternberg cells with the positivity of Epstein-Barr virus (EBV). She was diagnosed with MTX-related lymphoproliferative disorders (MTX-LPDs). She received chemotherapy after the cessation of MTX and IFX and achieved complete remission. RA showed recurrence after a while, and she was treated with steroids or other drugs. Six years after the chemotherapy, she experienced low-grade fever and anorexia. Whole computed tomography images showed an appendix tumor and enlargement of the surrounding lymph nodes. Appendectomy with the radical lymph nodes dissection was performed. The pathological diagnosis was diffuse large B-cell lymphoma, resulting in the clinical diagnosis of the relapse of MTX-LPD. EBV was negative at this point. The pathological findings of MTX-LPD may change at relapse; thus, biopsy should be considered when the relapse of MTX-LPD is suggested.

Conserved and context-dependent roles for pdgfrb signaling during zebrafish vascular mural cell development.

Platelet derived growth factor beta and its receptor, Pdgfrb, play essential roles in the development of vascular mural cells, including pericytes and vascular smooth muscle cells. To determine if this role was conserved in zebrafish, we analyzed pdgfb and pdgfrb mutant lines. Similar to mouse, pdgfb and pdgfrb mutant zebrafish lack brain pericytes and exhibit anatomically selective loss of vascular smooth muscle coverage. Despite these defects, pdgfrb mutant zebrafish did not otherwise exhibit circulatory defects at larval stages. However, beginning at juvenile stages, we observed severe cranial hemorrhage and vessel dilation associated with loss of pericytes and vascular smooth muscle cells in pdgfrb mutants. Similar to mouse, pdgfrb mutant zebrafish also displayed structural defects in the glomerulus, but normal development of hepatic stellate cells. We also noted defective mural cell investment on coronary vessels with concomitant defects in their development. Together, our studies support a conserved requirement for Pdgfrb signaling in mural cells. In addition, these zebrafish mutants provide an important model for definitive investigation of mural cells during early embryonic stages without confounding secondary effects from circulatory defects.

Alvocidib inhibits IRF4 expression via super-enhancer suppression and adult T-cell leukemia/lymphoma cell growth.

Adult T-cell leukemia/lymphoma (ATL) is an intractable hematological malignancy with extremely poor prognosis. Recent studies have revealed that super-enhancers (SE) play important roles in controlling tumor-specific gene expression and are potential therapeutic targets for neoplastic diseases including ATL. Cyclin-dependent protein kinase (CDK) 9 is a component of a complex comprising transcription factors (TFs) that bind the SE region. Alvocidib is a CDK9 inhibitor that exerts antitumor activity by inhibiting RNA polymerase (Pol) II phosphorylation and suppressing SE-mediated, tumor-specific gene expression. The present study demonstrated that alvocidib inhibited the proliferation of ATL cell lines and tumor cells from patients with ATL. RNA sequencing (RNA-Seq) and chromatin immunoprecipitation sequencing (ChIP-Seq) disclosed that SE regulated IRF4 in the ATL cell lines. Previous studies showed that IRF4 suppression inhibited ATL cell proliferation. Hence, IRF4 is a putative alvocidib target in ATL therapy. The present study revealed that SE-mediated IRF4 downregulation is a possible mechanism by which alvocidib inhibits ATL proliferation. Alvocidib also suppressed ATL in a mouse xenograft model. Hence, the present work demonstrated that alvocidib has therapeutic efficacy against ATL and partially elucidated its mode of action. It also showed that alvocidib is promising for the clinical treatment of ATL and perhaps other malignancies and neoplasms as well.

DENEB: Development of new criteria for curability after local excision of pathological T1 colorectal cancer using liquid biopsy.

According to the current international guidelines, high-risk patients diagnosed with pathological T1 (pT1) colorectal cancer (CRC) who underwent complete local resection but may have risk of developing lymph node metastasis (LNM) are recommended additional intestinal resection with lymph node dissection. However, around 90% of the patients without LNM are exposed to the risk of being overtreated due to the insufficient pathological criteria for risk stratification of LNM. Circulating tumor DNA (ctDNA) is a noninvasive biomarker for molecular residual disease and relapse detection after treatments including surgical and endoscopic resection of solid tumors. The CIRCULATE-Japan project includes a large-scale patient-screening registry of the GALAXY study to track ctDNA status of patients with stage II to IV or recurrent CRC that can be completely resected. Based on the CIRCULATE-Japan platform, we launched DENEB, a new prospective study, within the GALAXY study for patients with pT1 CRC who underwent complete local resection and were scheduled for additional intestinal resection with lymph node dissection based on the standard pathologic risk stratification criteria for LNM. The aim of this study is to explore the ability of predicting LNM using ctDNA analysis compared with the standard pathological criteria. The ctDNA assay will build new evidence to establish a noninvasive personalized diagnosis in patients, which will facilitate tailored/optimal treatment strategies for CRC patients.

Peri-arterial specification of vascular mural cells from naïve mesenchyme requires Notch signaling.

Mural cells (MCs) are essential for blood vessel stability and function; however, the mechanisms that regulate MC development remain incompletely understood, in particular those involved in MC specification. Here, we investigated the first steps of MC formation in zebrafish using transgenic reporters. Using pdgfrb and abcc9 reporters, we show that the onset of expression of abcc9, a pericyte marker in adult mice and zebrafish, occurs almost coincidentally with an increment in pdgfrb expression in peri-arterial mesenchymal cells, suggesting that these transcriptional changes mark the specification of MC lineage cells from naïve pdgfrblow mesenchymal cells. The emergence of peri-arterial pdgfrbhigh MCs required Notch signaling. We found that pdgfrb-positive cells express notch2 in addition to notch3, and although depletion of notch2 or notch3 failed to block MC emergence, embryos depleted of both notch2 and notch3 lost mesoderm- as well as neural crest-derived pdgfrbhigh MCs. Using reporters that read out Notch signaling and Notch2 receptor cleavage, we show that Notch activation in the mesenchyme precedes specification into pdgfrbhigh MCs. Taken together, these results show that Notch signaling is necessary for peri-arterial MC specification.

Nanofluidic Model Membrane for the Single-Molecule Observation of Membrane Proteins.

Membrane proteins play essential roles in the cell, and they constitute one of the most important targets of drugs. Studying membrane proteins in a controlled model membrane environment can provide unambiguous, quantitative information on their molecular properties and functions. However, reconstituting membrane proteins in a model system poses formidable technological challenges. Here, we developed a novel model membrane platform for highly sensitive observation of membrane proteins by combining a micropatterned lipid membrane and a nanofluidic channel. A micropatterned model membrane was generated by lithographically integrating a polymerized lipid bilayer and a natural (fluid) lipid bilayer. A nanofluidic channel having a defined thickness was formed between the fluid bilayer and a polydimethylsiloxane (PDMS) slab by attaching the polymeric bilayer and PDMS slab using an adhesion layer composed of silica nanoparticles that are coated with a biocompatible polymer brush. As we reconstituted rhodopsin (Rh), a G-protein-coupled receptor (GPCR), from a detergent-solubilized state into the fluid bilayer, only successfully reconstituted Rh molecules diffused laterally in the lipid bilayer and migrated into the nanogap junction, where they could be observed with a vastly improved signal-to-background ratio. The nanogap junction effectively separates the sites of reconstitution and observation and provides a novel platform for studying the molecular properties and functions of membrane proteins at the single-molecular level.

[Radiation-induced hematopoietic disorders].

Hematopoietic stem cells are one of the most sensitive tissues to radiation exposure. Epidemiological studies of atomic bomb survivors in Nagasaki and Hiroshima revealed a radiation dose-response relationship for acute myeloid leukemia, acute lymphoblastic leukemia, and Chronic myelogenous leukemia. In our study of myelodysplastic syndrome (MDS) in Nagasaki, the relative risk was higher in the proximal-exposed group. Additionally, the frequency of chromosome abnormalities associated with poor prognosis was higher in the proximal-exposed group than in the non-exposed group. However, no association between the exposure distance and prognosis was observed. We used next-generation sequencing to analyze the role of genetic abnormalities in the development of MDS. The results indicated that genetic mutations related to DNA methylation pathways, which are frequently observed in de novo MDS, were considerably less frequent in the proximal-exposed than in the distal-exposed group. These results suggest that the pathogenesis of MDS in atomic bomb survivors may be different from that of treatment-related and de novo MDS.

[Progressive multifocal leukoencephalopathy during the treatment for mycosis fungoides].

A 58-year-old man was diagnosed with mycosis fungoides (MF) confirmed by skin biopsy for systemic erythema that appeared in 2006 and had been on psoralen plus ultraviolet A (PUVA) therapy and topical steroids. In September 2017, he had diffuse large B-cell lymphoma and received chemotherapy. Since March 2019, tumor stage MF with large cell transformation was observed, and chemotherapy containing brentuximab vedotin (BV) was performed, which yielded a remarkable response. During the preparation for allogeneic hematopoietic stem cell transplantation, bradykinesia, delayed response, and cognitive decline were observed. Head magnetic resonance imaging fluid-attenuated inversion recovery images showed hyperintensity in the deep white matter below the bilateral frontal cortex. The general cerebrospinal fluid test revealed no abnormalities and was below the sensitivity of JC virus (JCV) quantitative PCR. As progressive multifocal leukoencephalopathy (PML) was strongly suspected from clinical symptoms and radiographic signs, ultrasensitive JCV testing was performed. The test result was positive; hence, the patient was diagnosed with PML. Chemotherapy was discontinued, but his central nervous system symptoms worsened, and he died on the 135th day of illness. We considered that PML developed based on the underlying disease and immunodeficiency caused by chemotherapy such as BV.