Evaluation of mycophenolic acid exposure in a patient with immune-related hepatotoxicity caused by nivolumab and ipilimumab therapy for malignant melanoma: a case report.

BACKGROUND: Guidelines such as the National Comprehensive Cancer Network recommend mycophenolate mofetil (MMF) for the treatment of severe steroid-refractory immune-related hepatotoxicity. Mycophenolic acid (MPA) is an active form of MMF that suppresses T- and B-lymphocyte proliferation and immune-related adverse events caused by immune checkpoint inhibitors. MPA has a narrow therapeutic range (37-70 µg·h/mL) and overexposure increases the risk of leukopenia in transplantation. However, the optimal use of MMF in oncology has not yet been established; thus, monitoring plasma MPA concentrations is necessary to avoid excessive immunosuppression in oncology practice. CASE PRESENTATION: We evaluated plasma MPA concentration in a 75-year-old man with immune-related hepatotoxicity following nivolumab and ipilimumab combination therapy for malignant melanoma. The patient developed severe hepatotoxicity after immunotherapy, and immunosuppressant therapy with corticosteroids was initiated. The patient then developed steroid-refractory immune-related hepatotoxicity; therefore, MMF (1,000 mg twice daily) was co-administered. Seven days after the administration of MMF, the plasma MPA concentration was measured using an enzyme multiplied immunoassay technique. The area under the plasma concentration-time curve for MPA from 0 to 12 h was 41.0 µg·h/mL, and the same dose of MMF was continued. Grade 2 lymphocytopenia, which could be attributed to MMF, was observed during the administration period. Unfortunately, the patient was infected with SARS-CoV-2 and died from respiratory failure. CONCLUSION: Our patient did not exceed the upper limit of MPA levels as an index of the onset of side effects of kidney transplantation and achieved rapid improvement in liver function. Prompt initiation of MMF after assessment of the steroid effect leads to adequate MPA exposure. Therapeutic drug monitoring should be considered when MMF is administered, to avoid overexposure.

Progression of duodenal neoplasia to advanced adenoma in patients with familial adenomatous polyposis.

BACKGROUND: Patients with familial adenomatous polyposis (FAP) have a lifetime risk of developing duodenal adenomas approaching 100%, and the relative risk for duodenal cancer compared with the general population is high. We conducted a retrospective study to investigate the progression of non-ampullary duodenal adenomas (NADAs) and risk factors for advanced lesions in patients with FAP. METHODS: Of 248 patients with 139 pedigrees at 2 institutes, we assessed 151 patients with 100 pedigrees with a pathogenic germline variant in the adenomatous polyposis coli gene, excluding mosaic variants. We evaluated the prevalence of NADAs in patients with FAP, the progression of these adenomas to advanced adenoma during the observation period, and the risk factors for the lifetime development of high-grade dysplasia (HGD), large (≥ 10 mm) duodenal adenomas, and Spiegelman stage IV. RESULTS: During the median observation period of 7 years, the incidences of patients with NADAs, with more than 20 polyps, with polyps ≥ 10 mm, with HGD, and with stage IV at the last esophagogastroduodenoscopy were increased 1.6-fold, 1.7-fold, 5-fold, 22-fold, and 9-fold, respectively. Intramucosal cancer occurred in three patients (2%), but no patients developed invasive cancer during the observation period because we performed endoscopic intervention for advanced adenomas. Stage progression was observed in 71% of 113 patients. Stage IV was more common in women, patients with a history of colectomy, and those with a 3' side mutation in their adenomatous polyposis coli gene. CONCLUSIONS: NADAs in patients with FAP frequently become exacerbated. Our findings suggest that patients with FAP who develop duodenal adenomas should be surveyed to prevent the development of duodenal cancer.

Genotype-phenotype correlation for extracolonic aggressive phenotypes in patients with familial adenomatous polyposis.

Familial adenomatous polyposis (FAP) patients develop various life-threatening extracolonic comorbidities that appear individually or within a family. This diversity can be explained by the localization of the adenomatous polyposis coli (APC) variant, but few reports provide definitive findings about genotype-phenotype correlations. Therefore, we investigated FAP patients and the association between the severe phenotypes and APC variants. Of 247 FAP patients, 126 patients from 85 families identified to have APC germline variant sites were extracted. These sites were divided into six groups (Regions A to F), and the frequency of severe comorbidities was compared among the patient phenotypes. Of the 126 patients, the proportions of patients with desmoid tumor stage ≥III, number of FGPs ≥1000, multiple gastric neoplasms, gastric neoplasm with high-grade dysplasia, and Spigelman stage ≥III were 3%, 16%, 21%, 12%, and 41%, respectively, while the corresponding rates were 30%, 50%, 70%, 50%, and 80% in patients with Region E (codons 1398-1580) variants. These latter rates were significantly higher than those for patients with variants in other regions. Moreover, the proportion of patients with all three indicators (desmoid tumor stage ≥III, number of FGPs ≥1000, and Spigelman stage ≥III) was 20% for those with variants in Region E and 0% for those with variants in other regions. Variants in Region E indicate aggressive phenotypes, and more intensive management is required.

Feasibility of underwater endoscopic mucosal resection for endoscopic management of gastric neoplasms in patients with familial adenomatous polyposis.

BACKGROUND: Underwater endoscopic mucosal resection (UEMR) has been developed as an effective endoscopic intervention for colon, rectum, and duodenum neoplasms. However, there are no comprehensive reports regarding the stomach, and its safety and efficacy are unknown. We aimed to examine the feasibility of UEMR for gastric neoplasms in patients with familial adenomatous polyposis (FAP). METHODS: We retrospectively extracted data of patients with FAP who underwent endoscopic resection (ER) for gastric neoplasms at Osaka International Cancer Institute from February 2009 to December 2018. Elevated gastric neoplasms of ≤ 20 mm in diameter were extracted, and conventional endoscopic mucosal resection (CEMR) and UEMR were compared. Furthermore, outcomes after ER until March 2020 were examined. RESULTS: 91 endoscopically resected gastric neoplasms were extracted from 31 patients with 26 pedigrees, and 12 neoplasms underwent CEMR and 25 neoplasms underwent UEMR was compared. The procedure time was shorter for UEMR than for CEMR. There was no significant difference between en bloc resection and R0 resection rates by EMR methods. CEMR and UEMR showed postoperative hemorrhage rates of 8% and 0%, respectively. Residual/local recurrent neoplasms were identified in four lesions (4%), but additional endoscopic intervention (three UEMR and one cauterization) resulted in a local cure. CONCLUSION: UEMR was feasible in gastric neoplasms of FAP patients, especially in elevated lesions and those of ≤ 20 mm in diameter.

Clinical Guidelines for Diagnosis and Management of Peutz-Jeghers Syndrome in Children and Adults.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is a rare disease characterized by the presence of hamartomatous polyposis throughout the gastrointestinal tract, except for the esophagus, along with characteristic mucocutaneous pigmentation. It is caused by germline pathogenic variants of the STK11 gene, which exhibit an autosomal dominant mode of inheritance. Some patients with PJS develop gastrointestinal lesions in childhood and require continuous medical care until adulthood and sometimes have serious complications that significantly reduce their quality of life. Hamartomatous polyps in the small bowel may cause bleeding, intestinal obstruction, and intussusception. Novel diagnostic and therapeutic endoscopic procedures such as small-bowel capsule endoscopy and balloon-assisted enteroscopy have been developed in recent years. SUMMARY: Under these circumstances, there is growing concern about the management of PJS in Japan, and there are no practice guidelines available. To address this situation, the guideline committee was organized by the Research Group on Rare and Intractable Diseases granted by the Ministry of Health, Labour and Welfare with specialists from multiple academic societies. The present clinical guidelines explain the principles in the diagnosis and management of PJS together with four clinical questions and corresponding recommendations based on a careful review of the evidence and involved incorporating the concept of the Grading of Recommendations Assessment, Development and Evaluation system. KEY MESSAGES: Herein, we present the English version of the clinical practice guidelines of PJS to promote seamless implementation of accurate diagnosis and appropriate management of pediatric, adolescent, and adult patients with PJS.

Promotion Effects of Smoking in Polyp Development in Monozygotic Twins with Atypical Colorectal Polyposis.

Smoking is a known risk factor for the development of colorectal polyps. Even in familial adenomatous polyposis and serrated polyposis syndrome, smoking is a risk factor of the development of polyps. Here, we report a case of monozygotic twins with atypical colorectal polyposis showing lots of hyperplastic polyps and adenomas and describe how the polyposis developed differently in the brothers based on the presence or absence of smoking. The case was of a set of monozygotic male twins, and the twins were in their 50s. The younger brother smoked 40 cigarettes a day since he was 16 years old. The older brother had smoked about 25 cigarettes a day since he was 16 years old but stopped smoking after he was diagnosed with polyposis. As we previously reported, we managed to remove polyps as much as possible from both twins without surgery. The median number of removed polyps (IQR: 25-75%) per colonoscopy for 20 years was 9.0 (3.5-14.8) in the older brother and 20.5 (7.5-35.5) in the younger brother. There was a significant difference between the twins (p < 0.01). Additionally, genetic tests found that the twins carried a rare missense variant of BRCA2, and this variation has not been previously reported. In conclusion, these monozygotic twins with atypical colorectal polyposis showing a new variant of BRCA2 suggest that smoking is related to the development of colorectal polyps. Further analysis will be required for the identified BRCA2 variant in possible involvement in the development of atypical polyposis.

Importance of sessile serrated lesions in a patient with familial adenomatous polyposis.

A 28-year-old male visited hospital because his mother had been diagnosed with familial adenomatous polyposis (FAP) with a pathological variant of the APC gene. Total colonoscopy showed that he has more than 100 polyps distributed throughout the colorectum, and the APC gene variant was also detected. After he was diagnosed with FAP, he received information that surgery was currently the only way to prevent the development of colorectal cancer. However, he firmly declined to undergo surgical procedures and decided to have strict follow-up with frequent endoscopic polypectomy to prevent the development of colorectal cancer. At the first endoscopy, polypectomy was performed on 52 polyps. Histological analysis of the dissected polyps showed that they were all adenomas, but adenocarcinoma was not detected. The second endoscopic polypectomy was performed after 4 months later. We found a pale 20 mm wide flat, elevated type polyp in the ascending colon with an adherent mucus cap that was resistant to washing off. After endoscopic mucosal resection, histological analysis revealed that there were two lesions in the polyps, a sessile serrated lesion (SSL) and SSL with dysplasia. SSL is a high-risk lesion for colorectal cancer, but it was reported to be rare in patients with FAP, and the existence of SSL suggested another carcinogenesis pathway in patients with FAP in addition to the adenoma-carcinoma sequence. Our report may be significant not only in consideration of the pathogenesis of FAP but also useful to raise awareness of SSL for clinicians who perform endoscopic polypectomy to prevent the development of colorectal cancer in patients with FAP.

Gastric neoplasms in patients with familial adenomatous polyposis: endoscopic and clinicopathologic features.

BACKGROUND AND AIMS: Gastric neoplasms in patients with familial adenomatous polyposis (FAP) occur at a high rate and can cause death. The endoscopic findings of gastric neoplasms in these patients are characteristic but not well recognized. To identify the relevant characteristics to enable early detection, we retrospectively investigated endoscopic findings of gastric neoplasms in patients with FAP and then compared the clinical, histopathologic, and genetic features among subgroups. METHODS: Of 234 patients with 171 pedigrees at 2 institutes, 56 cases (24%, 133 gastric neoplasms) with 44 pedigrees were examined. Immunostaining was performed for histopathologic evaluation by 1 blinded pathologist. According to the endoscopic findings, gastric neoplasms were divided into 4 types based on location (L: antrum and pylorus, UM: the rest of the stomach) and color (W: white, T: translucent, R: reddish) and their clinicopathologic features examined. RESULTS: Of the cases, 93% could be classified into a single type. Among histologic phenotypes, high-grade dysplasia was present in 26% (type L), 41% (type UM-W), 0% (type UM-T), and 22% (type UM-R). The immunologic phenotype comprised the gastric type in 69% (93% in Type UM) and the intestinal phenotype, including the mixed type, in 31% (61% in type L). Moreover, 96% of patients had concurrent duodenal neoplasms. Adenomatous polyposis coli gene status was identified in 93% of patients; the pathogenic variant was detected in 98% but did not influence any endoscopic features. CONCLUSIONS: Gastric neoplasms in patients with FAP were stratified into 4 types according to their endoscopic findings. The endoscopic phenotype was related to the histopathologic phenotype but not to germline variants.

Incidence and Clinical Features of Venous Thromboembolism in Hospitalized Patients With Coronavirus Disease 2019 (COVID-19) in Japan.

BACKGROUND: Coronavirus disease 2019 (COVID-19) reportedly causes venous thromboembolism (VTE), but the status of this complication in Japan was unclear.Methods and Results:The VTE and COVID-19 in Japan Study is a retrospective, multicenter cohort study enrolling hospitalized patients with COVID-19 who were evaluated with contrast-enhanced computed tomography (CT) examination at 22 centers in Japan between March 2020 and October 2020. Among 1,236 patients with COVID-19, 45 (3.6%) were evaluated with contrast-enhanced CT examination. VTE events occurred in 10 patients (22.2%), and the incidence of VTE in mild, moderate, and severe COVID-19 was 0%, 11.8%, and 40.0%, respectively. COVID-19 patients with VTE showed a higher body weight (81.6 vs. 64.0 kg, P=0.005) and body mass index (26.9 vs. 23.2 kg/m2, P=0.04), and a higher proportion had a severe status for COVID-19 compared with those without. There was no significant difference in the proportion of patients alive at discharge between patients with and without VTE (80.0% vs. 88.6%, P=0.48). Among 8 pulmonary embolism (PE) patients, all were low-risk PE. CONCLUSIONS: Among a relatively small number of patients undergoing contrast-enhanced CT examination in Japanese real-world clinical practice, there were no VTE patients among those with mild COVID-19, but the incidence of VTE seemed to be relatively high among severe COVID-19 patients, although all PE events were low-risk without significant effect on mortality risk.

Clinical Features of Venous Thromboembolism in Patients With Coronavirus Disease 2019 (COVID-19) in Japan　- A Case Series Study.

BACKGROUND: Suspicion that the coronavirus disease 2019 (COVID-19) caused venous thromboembolism (VTE).Methods and Results:We conducted a case series study of 5 VTE patients with COVID-19 in Japan. The median body mass index was 27.7 kg/m2, and all patients required mechanical ventilation during hospitalization. Patients were diagnosed as VTE in the intensive care unit (ICU), general ward, and outpatient ward. CONCLUSIONS: The current case series study revealed some clinical features of VTE patients with COVID-19 in Japan, including obese patients and those requiring mechanical ventilation during hospitalization, who should be followed closely for VTE, even after leaving the ICU.

Long-term outcomes after endoscopic submucosal dissection for differentiated-type early gastric cancer that fulfilled expanded indication criteria: A prospective cohort study.

BACKGROUND AND AIM: Endoscopic resection for early gastric cancer (EGC) is widely performed. However, there is still a paucity of strong evidence regarding long-term outcomes after endoscopic submucosal dissection (ESD) for the expanded indication criteria of the Japanese guidelines (ver. 2010). METHODS: Endoscopic submucosal dissection was performed in patients with EGC that met the expanded indication criteria: (i) cT1a, differentiated-type EGC of 2 to 5 cm, ulcer negative or (ii) cT1a, differentiated-type EGC of ≤3 cm, ulcer positive. Patients whose pathological examination fulfilled the curative resection criteria were then enrolled in this cohort study: negative vertical margin, negative lymphovascular invasion, and (i) pT1a, differentiated-type, and ulcer negative; (ii) pT1a, differentiated-type, ≤3 cm, and ulcer positive; or (iii) pT1b1 (<500-µm submucosal invasion), differentiated-type, and ≤3 cm. Patients with only a positive horizontal margin as a noncurative factor were included for follow-up. RESULTS: From September 2003 to February 2012, a total of 356 patients underwent ESD, and 214 were enrolled in the survival analysis. One hundred twenty patients (56%) had >2 cm in diameter and ulcer-negative lesions, and 94 (44%) had ≤3 cm and ulcer-positive lesions. The vital status at 5 years after ESD was confirmed in all (100%) patients. No local or metastatic recurrence was detected; however, 26 metachronous gastric cancers developed, and 1 patient died of metachronous gastric cancer. The 5-year disease-specific and overall survival rates were 99.5% (95% confidence interval [CI], 97.2%-100%) and 93.9% (95% CI, 89.8%-96.4%), respectively. CONCLUSION: ESD for EGC that fulfills the expanded criteria is feasible and shows favorable long-term outcomes.

Influence of Type 2 Endoleaks on Long-Term Outcomes after Endovascular Repair for Abdominal Aortic Aneurysms: A National Hospital Organization Network Study for Abdominal Aortic Aneurysms in Japan.

BACKGROUND: Although endovascular repair (EVAR) is the first-line treatment for abdominal aortic aneurysm, type 2 endoleak (EL), which is associated with late sac enlargement or rupture, remains a concern. The present study aimed to assess the influence of type 2 EL on long-term outcomes after EVAR. METHODS: Among 550 patients who underwent EVAR between 2007 and 2013 at 14 Japanese national hospitals, 135 patients had type 2 EL diagnosed on follow-up computed tomography (CT) within 12 months after EVAR (EL2[+] group) and 415 patients did not have EL within 12 months (EL2[-] group). The cumulative incidences of sac enlargement, late intervention, and aneurysm-related death after EVAR were estimated using the cumulative incidence function method, and prognostic factors were investigated using the Fine-Gray hazard model. RESULTS: The median follow-up period was 5 years, and the 5-year cumulative incidence rates of sac enlargement, late intervention, and aneurysm-related death were 30.7% ± 4.4%, 25.3% ± 4.1%, and 2.6% ± 1.4%, respectively, in the EL2(+) group, and 8.7% ± 1.6%, 7.6% ± 1.4%, and 0.3% ± 0.3%, respectively, in the EL2(-) group. The cumulative incidence rates of sac enlargement (P = 0.002), late intervention (P < 0.001), and aneurysm-related death (P = 0.015) were significantly different between the 2 groups. As the first-line treatment for sac enlargement with type 2 EL, transcatheter coil embolization was performed in 30 patients. Information about sac behavior on CT after coil embolization was available in 20 of the 30 patients. Among these patients, no patients experienced sac shrinkage, and the aneurysmal sac dilated after coil embolization in 18 patients. CONCLUSIONS: Type 2 EL affects the long-term outcomes after EVAR. It is not recommended to observe large aneurysmal sacs conservatively as they tend to dilate in the presence of type 2 EL.

A Simple Method for Measuring Adenosine Triphosphate in Acute Cholangitis Patients to Determine the Need for Emergency Biliary Drainage.

Objective Acute cholangitis is occasionally life-threatening and requires immediate treatment. For the management of acute cases, globally accepted diagnostic criteria and the use of severity grading, as defined in the Tokyo Guidelines 2018 (TG18), are recommended. This study was performed to explore the association between acute cholangitis and the level of adenosine 5'-triphosphate (ATP) in blood as determined with a simple measurement method. Methods Twenty-three consecutive patients admitted for acute cholangitis and 14 healthy individuals were enrolled. Based on the TG18, the patients were categorized according to the degree of severity as Grade I, II, or III. We measured the amount of ATP in blood samples using a bioluminescence meter and evaluated the correlation with the degree of severity. Results The ATP/total hemoglobin (tHgb) level showed a significant decline in association with an increase in severity, as that in the healthy controls was 236.60 ± 8.10 and in the Grade I, II, and III groups was 238.56 ± 6.98, 186.88 ± 7.62, and 154.60 ± 11.01, respectively (p<0.01). While no significant difference was observed between the healthy controls and Grade I patients (p=0.649), there was a statistically significant difference between Grade I and Grade II (p<0.01) in the ATP/tHgb level. According to a receiver operating characteristic analysis, the area under the curve for ATP/tHgb, used as an index for predicting the need for emergency biliary drainage (Grade II, III cases), was the highest among various examined factors. Conclusion The present novel measurement method was found to be simple to perform and useful for detecting acute cholangitis patients with a low ATP level who may require emergency biliary drainage.

Endogenous reference RNAs for microRNA quantitation in formalin-fixed, paraffin-embedded lymph node tissue.

Lymph node metastasis is one of the most important factors for tumor dissemination. Quantifying microRNA (miRNA) expression using real-time PCR in formalin-fixed, paraffin-embedded (FFPE) lymph node can provide valuable information regarding the biological research for cancer metastasis. However, a universal endogenous reference gene has not been identified in FFPE lymph node. This study aimed to identify suitable endogenous reference genes for miRNA expression analysis in FFPE lymph node. FFPE lymph nodes were obtained from 41 metastatic cancer and from 16 non-cancerous tissues. We selected 10 miRNAs as endogenous reference gene candidates using the global mean method. The stability of candidate genes was assessed by the following four statistical tools: BestKeeper, geNorm, NormFinder, and the comparative ΔCt method. miR-103a was the most stable gene among candidate genes. However, the use of a single miR-103a was not recommended because its stability value exceeded the reference value. Thus, we combined stable genes and investigated the stability and the effect of gene normalization. The combination of miR-24, miR-103a, and let-7a was identified as one of the most stable sets of endogenous reference genes for normalization in FFPE lymph node. This study may provide a basis for miRNA expression analysis in FFPE lymph node tissue.

Intramucosal colorectal carcinoma with invasion of the lamina propria: a study by the Japanese Society for Cancer of the Colon and Rectum.

Cancer invasion of the lamina propria is an important pathological finding. However, the clinicopathologic features and diagnostic accuracy of intramucosal carcinoma assessment in colorectal carcinoma (CRC) are unknown. In this study, intramucosal CRCs were reviewed in institutions affiliated with the Japanese Society for Cancer of the Colon and Rectum, and 32 cases with invasion of the lamina propria were identified. Next, a consensus meeting was held to select cases with a high consensus about the presence of invasion, which were reviewed by one Western pathologist for confirmation. In addition to clinicopathologic evaluation, concordance was assessed for diagnosis and histologic findings. During the consensus meeting, 3 cases were found to show ambiguous features such that it was unclear whether there was intramucosal or submucosal invasion, and 7 cases were judged to have invasion of the lamina propria by more than 75% of the pathologists. A poorly differentiated adenocarcinoma and a signet ring cell carcinoma were diagnosed unanimously. Concordance in diagnosis and detection of characteristics of invasion of the lamina propria proved to be only poor to fair. Single or small clusters of cells and atypical or complex glandular arrangements that are beyond normal mucosal architecture were detected more frequently in the 7 high-consensus tumors. Desmoplasia and marked inflammation were detected more often in cases characterized as ambiguous. Intramucosal CRCs with invasion of the lamina propria constituted 5.1% of the surgically resected high-grade intramucosal epithelial dysplastic/neoplastic lesions, and stromal infiltration of single or small clusters of cells is the best objective criterion of invasion.

Lymphoplasmacytic Lymphoma Presenting with Diarrhea and Joint Pain Which was Successfully Diagnosed by an MYD88 Mutation Analysis.

A 55-year-old man presented to our department with diarrhea, weight loss, fatigability, and polyarthralgia. Blood tests revealed elevated soluble interleukin-2 receptor levels and IgG-type M protein positivity, without any findings that were suggestive of collagen disease. After computed tomography (CT) detected enlarged lymph nodes in the abdominal para-aortic region, lymphoma was suspected. CT-guided needle biopsy of the lymph node did not help to achieve a definitive diagnosis; however, a bone marrow test showed the pathological features of B-cell lymphoma. A genetic examination detected a MYD88 L265P mutation; the mutation analysis was valuable in diagnosing lymphoplasmacytic lymphoma in a IgM-type M protein-negative patient.

Interstitial lung disease associated with trastuzumab monotherapy: A report of 3 cases.

We herein report 3 cases of female patients with breast cancer who developed interstitial lung disease (ILD) during trastuzumab monotherapy in an adjuvant setting. Prior chemotherapy included 4 cycles of epirubicin and cyclophosphamide in patients 1 and 2, and 4 cycles of docetaxel, cyclophosphamide and trastuzumab in patient 3. Patient 1 presented with a cough and fever after the fourth cycle of trastuzumab. Patient 2 experienced rapid deterioration of oxygen saturation without subjective symptoms within 3 h of the first administration of trastuzumab. Patient 3 was unexpectedly diagnosed with organizing pneumonia in a scheduled computed tomography (CT) scan after the first course of trastuzumab. Based on clinical data, such as decreased PaO2 level, increased serum levels of KL-6 and/or lactate dehydrogenase, and findings on chest CT, these patients were diagnosed with drug-induced ILD. Considering the clinical course, trastuzumab was incriminated as the cause of ILD, particularly in patients 1 and 2. All 3 patients improved due to the timely diagnosis, discontinuation of trastuzumab and immediate administration of corticosteroid therapy. Although ILD is a rare adverse event associated with trastuzumab, it may cause rapid deterioration without preceding symptoms. Close observation and early diagnosis are required to avoid an unfavorable outcome.

A Case of Heparin-Induced Thrombocytopenia Type 2 after Repair of Juxtarenal Abdominal Aortic Aneurysm.

Heparin-induced thrombocytopenia (HIT) is still a relatively uncommon condition and it is not well known how to administer argatroban during continuous hemodiafiltration (CHDF). A 72-year-old man required CHDF with heparin because of the oliguria and hyperpotassemia directly after the open repair of a juxtarenal abdominal aortic aneurysm. As the postoperative blood platelet count dropped and there was a thrombus in the CHDF circuit, HIT was suspected and nafamostat mesilate, but not heparin, was immediately administered for CHDF. As heparin-platelet factor 4 complex was positive, we diagnosed him with HIT and started argatroban while monitoring the activated clotting time (ACT), resulting in no further obstruction of the CHDF and an increase in the platelets. There was no disadvantage for administering nafamostat mesilate which we have commonly used instead of heparin, we should have used argatroban once we suspected HIT. It may be important to consider the history of heparin especially in administering heparin and it may be useful to monitor the ACT when initially starting argatroban for patients with HIT.

Revascularization for acute blunt popliteal artery injury.

Case: A 45-year-old man was brought to our hospital in pre-shock after falling from a motorcycle. As we diagnosed him with open fracture of the right femur with leg ischemia, we performed revascularization of injured popliteal artery and treated the leg. The pathological findings showed fragmentation and decrease of elastic fibers and fragmentation of collagen fibers, but no inflammatory cells or intimal hyperplasia, and no dissection. Outcome: Unfortunately, amputation had to be carried out on the 29th postoperative day due to infection and leg dysfunction. The postoperative course was uneventful. The patient could walk with an artificial leg and was discharged approximately 5 months after popliteal artery replacement. Conclusions: We report a case of revascularization involving a patient with open fracture of the right femur due to acute blunt popliteal artery injury.

Dialister pneumosintes bacteremia caused by dental caries and sinusitis.

A 62-year-old Japanese woman was hospitalized at the Department of Senology for positive signals on two sets of blood cultures obtained in the Emergency Department. The initial physical examination with enhanced computed tomography of the chest and abdomen did not identify the infectious source. Dialister pneumosintes was identified on 16S rRNA sequencing, and dental caries with sinusitis were subsequently diagnosed based on a dental examination and magnetic resonance imaging. History taking with respect to dental hygiene and oral examinations should be performed in daily clinical practice, especially in immunosuppressed patients.