Soret-Effect Induced Phase-Change in a Chromium Nitride Semiconductor Film.

Phase-change materials such as Ge-Sb-Te (GST) exhibiting amorphous and crystalline phases can be used for phase-change random-access memory (PCRAM). GST-based PCRAM has been applied as a storage-class memory; however, its relatively low ON/OFF ratio and the large Joule heating energy required for the RESET process (amorphization) significantly limit the storage density. This study proposes a phase-change nitride, CrN, with a much wider programming window (ON/OFF ratio more than 105) and lower RESET energy (one order of magnitude reduction from GST). High-resolution transmission electron microscopy revealed a phase-change from the low-resistance cubic CrN phase into the highly resistive hexagonal CrN2 phase induced by the Soret-effect. The proposed phase-change nitride could greatly expand the scope of conventional phase-change chalcogenides and offer a strategy for the next-generation of PCRAM, enabling a large ON/OFF ratio (∼105), low switching energy (∼100 pJ), and fast operation (∼30 ns).

Frontal pole-precuneus connectivity is associated with a discrepancy between self-rated and observer-rated depression severity in mood disorders: a resting-state functional magnetic resonance imaging study.

Discrepancies in self-rated and observer-rated depression severity may underlie the basis for biological heterogeneity in depressive disorders and be an important predictor of outcomes and indicators to optimize intervention strategies. However, the neural mechanisms underlying this discrepancy have been understudied. This study aimed to examine the brain networks that represent the neural basis of the discrepancy between self-rated and observer-rated depression severity using resting-state functional MRI. To examine the discrepancy between self-rated and observer-rated depression severity, self- and observer-ratings discrepancy (SOD) was defined, and the higher and lower SOD groups were selected from depressed patients as participants showing extreme deviation. Resting-state functional MRI analysis was performed to examine regions with significant differences in functional connectivity in the two groups. The results showed that, in the higher SOD group compared to the lower SOD group, there was increased functional connectivity between the frontal pole and precuneus, both of which are subregions of the default mode network that have been reported to be associated with ruminative and self-referential thinking. These results provide insight into the association of brain circuitry with discrepancies between self- and observer-rated depression severity and may lead to more treatment-oriented diagnostic reclassification in the future.

The fatal case of "Pigmentibacter" bacteremia following aspiration pneumonia in elderly patient.

"Pigmentibacter ruber" was first reported in 2021, a novel bacterium of the family Silvanigrellaceae, isolated from human blood of the patient with aspiration pneumonia after the drowning accident in Republic of China. However, until now, there is only one report describing "P. ruber" infection, and no case of isolation from natural environment has been reported so far. Thus, the infectivity and pathogenicity of "Pigmentibacter" spp. has not been clearly understood. In this report, we described the fatal case of "Pigmentibacter" bacteremia subsequently occurred after aspiration pneumonia probably due to accidental ingestion of irrigation water in the elderly patient. Despite administration of broad-spectrum antibiotic, the patient dramatically deteriorated and eventually deceased. Whole-genome sequencing showed the strain isolated from the patient was identified as "Pigmentibacter" sp. (designated as strain Takaoka) and antimicrobial sensitivity testing showed it displayed high minimum inhibitory concentrations against various antibiotics including ß-lactam. Further studies are needed to clarify the clinical characteristics of "Pigmentibacter" and its relative's infections and their antimicrobial sensitivity; however, the present case supported the clinical characteristics of "Pigmentibacter" infection, which can lead to bacteremia following aspiration pneumonia caused by mis-swallowing contaminated water, and poor outcome potentially due to multidrug resistances.

Lower Dose of 5 mL of 1% Lidocaine is More Suitable than the Conventional 10 mL for Caudal Block in Transrectal Prostate Biopsy: A Retrospective Cohort Study.

Objectives: In Japan, caudal block with 1% lidocaine is commonly used for transrectal prostate biopsy. Although 10 mL of 1% lidocaine is commonly used, the appropriate dosage of 1% lidocaine has not been studied. Our hospital routinely uses two different doses (5 or 10 mL) of 1% lidocaine for caudal block for transrectal prostate biopsy. Herein, we retrospectively evaluated the efficacy and safety of both doses of 1% lidocaine. Methods: This retrospective study included 869 patients who underwent transrectal prostate biopsy with caudal block at our hospital. The amount of 1% lidocaine was determined by the day of the week on which the biopsy was performed, and the patient voluntarily chose the day of the biopsy, unaware of the dose of 1% lidocaine used on that day. Pain, anal sphincter tonus, cancer diagnosis rate, and early complications were compared. Results: In total, 466 and 403 patients received 5 and 10 mL of 1% lidocaine for a caudal block, respectively. After propensity-score matching for patient characteristics, each group contained 395 patients. The pain score, anal sphincter tonus score, or prostate cancer diagnosis rate were not significantly different between the two groups. However, rectal bleeding was significantly more frequent and severe in the 10-mL than the 5-mL group (p=0.018 and p=0.0036, respectively). The incidence of other complications was not significantly different between the groups. Conclusions: Our results suggest that 5 mL of 1% lidocaine may be more suitable than 10 mL for caudal block during transrectal prostate biopsy.

Impact of combined pulmonary fibrosis and emphysema on lung cancer risk and mortality in rheumatoid arthritis: A multicenter retrospective cohort study.

OBJECTIVE: Combined pulmonary fibrosis and emphysema (CPFE) is a syndrome characterized by the coexistence of emphysema and fibrotic interstitial lung disease (ILD). The aim of this study was to examine the effect of CPFE on lung cancer risk and lung cancer-related mortality in patients with rheumatoid arthritis (RA). METHODS: We conducted a multicenter retrospective cohort study of patients newly diagnosed with lung cancer at five community hospitals between June 2006 and December 2021. Patients were followed until lung cancer-related death, other-cause death, loss to follow-up, or the end of the study. We used the cumulative incidence function with Gray's test and Fine-Gray regression analysis for survival analysis. RESULTS: A total of 563 patients with biopsy-proven lung cancer were included (82 RA patients and 481 non-RA patients). The prevalence of CPFE was higher in RA patients than in non-RA patients (40.2% vs.10.0%) at lung cancer diagnosis. During follow-up, the crude incidence rate of lung cancer-related death was 0.29 and 0.10 per patient-year (PY) in RA and non-RA patients, and 0.32 and 0.07 per PY in patients with CPFE and patients without ILD or emphysema, respectively. The estimated death probability at 5 years differed between RA and non-RA patients (66% vs. 32%, p<0.001) and between patients with CPFE and patients without ILD or emphysema (71% vs. 24%, p<0.001). In addition to clinical cancer stage and no surgery within 1 month, RA and CPFE were identified as independent predictive factors for increased lung cancer-related mortality (RA: adjusted hazard ratio [HR], 2.49; 95% confidence interval [CI], 1.65-4.76; CPFE: adjusted HR 2.01; 95% CI 1.24-3.23). CONCLUSIONS: RA patients with lung cancer had a higher prevalence of CPFE and increased cancer-related mortality compared with non-RA patients. Close monitoring and optimal treatment strategies tailored to RA patients with CPFE are important to improve the poor prognosis of lung cancer.

Effect of Recent Antirheumatic Drug on Features of Rheumatoid Arthritis-Associated Lymphoproliferative Disorders.

OBJECTIVE: In this study, we examine how advancements in novel antirheumatic drugs affect the clinicopathologic features of lymphoproliferative disorder (LPD) in patients with rheumatoid arthritis (RA). METHODS: In this multicenter study across 53 hospitals in Japan, we characterized patients with RA who developed LPDs and visited the hospitals between January 1999 and March 2021. The statistical tools used included Fisher's exact test, the Mann-Whitney U-test, the log-rank test, logistic regression analysis, and Cox proportional hazards models. RESULTS: Overall, 752 patients with RA-associated LPD (RA-LPD) and 770 with sporadic LPD were included in the study. We observed significant differences in the clinicopathologic features between patients with RA-LPD and those with sporadic LPD. Histopathological analysis revealed a high frequency of LPD-associated immunosuppressive conditions. Furthermore, patients with RA-LPD were evaluated based on the antirheumatic drugs administered. The methotrexate (MTX) plus tacrolimus and MTX plus tumor necrosis factor inhibitor (TNFi) groups had different affected site frequencies and histologic subtypes than the MTX-only group. Moreover, MTX and TNFi may synergistically affect susceptibility to Epstein-Barr virus infection. In case of antirheumatic drugs administered after LPD onset, tocilizumab (TCZ)-only therapy was associated with lower frequency of regrowth after spontaneous regression than other regimens. CONCLUSION: Antirheumatic drugs administered before LPD onset may influence the clinicopathologic features of RA-LPD, with patterns changing over time. Furthermore, TCZ-only regimens are recommended after LPD onset.

Nonvolatile Isomorphic Valence Transition in SmTe Films.

The burgeoning field of optoelectronic devices necessitates a mechanism that gives rise to a large contrast in the electrical and optical properties. A SmTe film with a NaCl-type structure demonstrates significant differences in resistivity (over 105) and band gap (approximately 1.45 eV) between as-deposited and annealed films, even in the absence of a structural transition. The change in the electronic structure and accompanying physical properties is attributed to a rigid-band shift triggered by a valence transition (VT) between Sm2+ and Sm3+. The stress field within the SmTe film appears closely tied to the mixed valence state of Sm, suggesting that stress is a driving force in this VT. By mixing the valence states, the formation energy of the low-resistive state decreases, providing nonvolatility. Moreover, the valence state of Sm can be regulated through annealing and device-operation processes, such as applying voltage and current pulses. This investigation introduces an approach to developing semiconductor materials for optoelectrical applications.

Clinical disease activity is a major determinant of plasma D-dimer elevation in outpatients with rheumatoid arthritis: A hospital-based cross-sectional study.

OBJECTIVES: To identify factors associated with plasma D-dimer levels in outpatients with rheumatoid arthritis (RA). METHODS: We consecutively recruited 460 RA patients who visited our hospital for routine follow-ups between June and October 2021. Plasma D-dimer, RA-related characteristics, comorbidities, and cardiovascular and venous thromboembolism (VTE) risk factors were examined at enrolment. Patients with elevated D-dimer levels underwent whole-leg venous ultrasonography to diagnose deep vein thrombosis (DVT). RESULTS: Participants had no DVT signs or symptoms. Among them, 252 (54.8%) were positive for plasma D-dimer (≥0.5 µg/ml) and 40 (8.7%) had high D-dimer levels (≥3 µg/ml). The mean was 1.07 µg/ml. After adjustments, age [odds ratio (OR) 1.88 per additional 10 years, P = .003], high and moderate clinical disease activity index (OR 8.79, P < .001), and the presence of comorbidities or cardiovascular/VTE risk factors (OR 2.94, P = .017) were identified as the factors independently associated with high D-dimer levels. Among patients with D-dimer levels ≥3 µg/ml, 10 (25%) had DVT in their lower limbs, and D-dimer levels were significantly higher in patients with DVT compared with those without it (mean 6.0 vs. 4.1 µg/ml, P < .001). CONCLUSIONS: Clinical disease activity is a major contributor to plasma D-dimer elevation in RA outpatients.

Adenocarcinoma in ectopic prostatic tissue at the trigone of urinary bladder.

Introduction: Ectopic prostatic tissue is prostatic tissue located distant from the prostate gland. Although its existence is not uncommon, the occurrence of adenocarcinoma in ectopic prostatic tissue is rare. Case presentation: A 68-year-old man was suspected to have a nodular-type tumor in the bladder trigone and a tumor in the prostate based on magnetic resonance imaging and cystoscopy results. Transurethral tumor resection and transrectal prostate needle biopsy revealed the coexistence of ectopic prostatic adenocarcinoma in the bladder trigone and low-risk orthotopic prostate cancer. Four years later, the tumor evolved to intermediate-risk prostate cancer during active surveillance, and the patient underwent prostatectomy with resection of the bladder trigone. Pathology indicated no residual ectopic prostatic tissue or adenocarcinoma at the bladder trigone. Conclusion: Adenocarcinoma in ectopic prostatic tissue is very rare; however, when found, the possibility of concurrent cancer in the prostate gland should be considered.

Photoinduced Nonvolatile Displacive Transformation and Optical Switching in MnTe Semiconductors.

MnTe is considered a promising candidate for next-generation phase change materials owing to the reversible and nonvolatile phase transformation between its α and ß' phases by irradiation of a nanosecond laser or application of a pulse voltage. In this work, for a faster phase control of MnTe, the response of metastable ß-MnTe thin films to femtosecond (fs) laser irradiation was investigated. Using ultrafast optical spectroscopy, we inferred transient phase transformation. Moreover, with an increase in laser-excitation fluence, a nonvolatile structural change from the ß to α phase was experimentally observed by Raman spectroscopy and transmission electron microscopy without ablation damage on the sample. The observation results strongly suggest that the fs-laser-induced ß â†’ α phase transformation proceeds through the nucleation and growth mode without a large temperature increase.

Impact of Conducting Adrenal Venous Sampling in the Morning Versus Afternoon in Primary Aldosteronism.

Context: Adrenal venous sampling (AVS) is the gold standard technique for subtype differentiation of primary aldosteronism (PA) and to obtain aldosterone and cortisol measurements; however, their secretion patterns show fluctuations during the day. Objective: We aimed to examine the effects of AVS timing on AVS results. Methods: This multicenter, retrospective, observational study included a total of 753 patients who were diagnosed with PA and underwent AVS in 4 centers in Japan. Among them, 504 and 249 patients underwent AVS in the morning (AM-AVS) and in the afternoon (PM-AVS), respectively. The outcome measures were the impact of AVS timing and hormone fluctuations in a day on AVS results. Results: There were no differences in the success rate of AVS, diagnostic rate of disease type, or frequency of discrepancy in PA subtypes between the AM-AVS and PM-AVS groups. Regarding patients with unilateral PA, aldosterone concentrations in adrenal venous blood did not differ between the 2 groups on the dominant or nondominant side. Conversely, regarding patients with bilateral PA, aldosterone concentrations in adrenal venous blood were significantly higher in the AM-AVS than in the PM-AVS group. Conclusions: The timing of AVS did not seem to have a significant impact on subtype diagnosis. The aldosterone levels in adrenal venous blood were significantly higher in patients with bilateral PA in the AM-AVS group, but there was no such difference between patients with unilateral PA in the AM-AVS and PM-AVS groups. Each subtype may have a different hormone secretion pattern in a day.

Outcomes and risk factors for mortality in Pneumocystis pneumonia patients with rheumatoid arthritis: A multicentre retrospective cohort study.

OBJECTIVES: The aim is to evaluate outcomes and risk factors for death in patients with rheumatoid arthritis (RA) who developed Pneumocystis pneumonia (PCP). METHODS: We included RA patients who were diagnosed with PCP at seven participating community hospitals between July 2005 and October 2020. Clinical features were compared between survivors and non-survivors. Disease-modifying antirheumatic drugs (DMARDs) before PCP onset and after PCP recovery were also examined. RESULTS: Seventy RA patients developed PCP, and among them, 60 (85.7%) received methotrexate (MTX) monotherapy (40%) or MTX combination therapy with other DMARDs (45.7%). PCP was more likely to occur after 12 months of MTX monotherapy and within 3 months of MTX combination therapy. Thirteen patients (18.6%) died despite PCP treatment. Multivariable logistic regression analysis revealed that coexisting RA-associated interstitial lung disease (odds ratio, 6.18; 95% confidence interval, 1.17-32.63) and delayed PCP treatment with anti-Pneumocystis drugs (odds ratio, 15.29; 95% confidence interval, 1.50-156.15) are significant risk factors for PCP mortality in RA patients. Most survivors successfully resumed DMARD therapy without PCP prophylaxis; one recurrent PCP case was observed during follow-up (median, 4.1 years). CONCLUSIONS: To avoid a treatment delay, RA patients should be followed up for signs and symptoms of PCP development, especially those with RA-associated interstitial lung disease.

Impact of Janus kinase inhibitors on antibody response to 13-valent pneumococcal conjugate vaccine in patients with rheumatoid arthritis.

OBJECTIVES: To evaluate the antibody response to 13-valent pneumococcal conjugate vaccine (PCV13) in patients with rheumatoid arthritis receiving Janus kinase inhibitors (JAKIs). METHODS: Fifty-three patients receiving methotrexate (MTX; n = 10), JAKI (n = 20), or MTX + JAKI (n = 23) were vaccinated with PCV13. Serum concentrations of immunoglobulin G (IgG) antibodies to 13 pneumococcal serotype capsular polysaccharides were quantified before and 4-6 weeks after vaccination. Positive antibody response was defined as a 2-fold or more increase in IgG concentrations from prevaccination levels. RESULTS: After vaccination, IgG concentrations significantly increased in all treatment groups (P <0.001), but fold increases (postvaccination to prevaccination ratios) were different among treatment groups (9.30 for MTX, 6.36 for JAKI, and 3.46 for combination therapy). Positive antibody response rates were comparable between the MTX group (90%) and the JAKI group (95%) but lower in the MTX + JAKI group (52.2%). In a multivariable logistic regression analysis, the combination therapy was the only factor associated with a reduced antibody response to PCV13. No severe adverse events were observed in any treatment group. CONCLUSION: Although JAKIs do not impair PCV13 immunogenicity in rheumatoid arthritis patients, the combination of MTX with JAKI can reduce the antibody response in this patient population.

Relationship between high trait anxiety in 22q11.2 deletion syndrome and the difficulties in medical, welfare, and educational services.

Aim: The 22q11.2 deletion syndrome (22q11DS) is associated with a high prevalence of mental health comorbidities. However, not enough attention has been paid to the elevated prevalence of high trait anxiety that begins early in life and may be enduring. We sought to identify specific medical, welfare, or educational difficulties associated with high trait anxiety in 22q11DS. Methods: A questionnaire-based survey was conducted for the parents of 22q11DS individuals (N = 125). First, a multiple regression analysis was conducted to confirm the hypothesis that high trait anxiety in individuals with 22q11DS would be associated with parents' psychological distress. This was based on 19 questionnaire options regarding what difficulties the parents currently face about their child's disease, characteristics, and traits. Next, we explored what challenges faced in medical, welfare, and educational services would be associated with the trait anxiety in their child. Results: The multiple regression analysis confirmed that the high trait anxiety was significantly associated with parental psychological distress (ß = 0.265, p = 0.018) among the 19 clinical/personal characteristics of 22q11DS. Furthermore, this characteristic was associated with various difficulties faced in the medical care, welfare, and education services, and the parent-child relationship. Conclusion: To our knowledge, this is the first study to clarify quantitatively how the characteristic of high anxiety level in 22q11DS individuals is related to the caregivers' perceived difficulties in medical, welfare, and educational services. These results suggest the necessity of designing service structures informed of the fact that high trait anxiety is an important clinical feature of the syndrome.

Cerebral syphilitic gumma mimicking a brain tumor that enlarged temporarily after commencing antibiotic treatment.

In this case report, we describe a 60-year-old man who presented with headaches for 1 year and mild confusion for 3 weeks and was initially diagnosed as having a cerebral tumor on the basis of finding a round lesion in the right lenticular nucleus with ring enhancement on gadolinium-enhanced T1-weighted brain magnetic resonance imaging. However, the discovery of positive serology for Treponema pallidum infection on routine tests on admission prompted analysis of cerebrospinal fluid, which was also positive on Treponema pallidum hemagglutination (TPHA), rapid plasma reagin (RPR), and treponemal antibody absorption (FTA-ABS) tests. Thus, he was diagnosed as having an intracranial syphilitic gumma. After commencing treatment with penicillin G, the lesion temporarily increased in size, but subsequently resolved completely with continuing antibiotic treatment. In the present era of increasing prevalence of syphilitic infection and because they are eminently treatable, syphilitic gummas should be included in the differential diagnosis of apparent brain tumors. Additionally, temporary enlargement of a probable gumma after instituting antibiotic treatment should not prompt cessation or change of the antibiotics.

Oligometastatic Lymph Node Recurrence Detected Using 18F-PSMA-1007 PET/CT in a Patient With Castration-resistant Prostate Cancer After Radiation Therapy.

BACKGROUND/AIM: Prostate cancer (PC) is one of the most common types of cancer in men worldwide. Most patients with metastatic PC are treated with androgen deprivation therapy (ADT) using luteinizing hormone-releasing hormone agonists and antagonists as first-line therapy. The majority of PC patients develop a castration-resistant PC (CRPC), which eventually leads to high mortality with poor prognosis, despite new targeted therapies. However, given that oligometastatic recurrence may enable local therapy in CRPC, accurate detection of metastatic lesions may improve clinical outcomes in patients with CRPC. CASE REPORT: We report the case of an 83-year-old man with CRPC. 18Fluorine-prostate-specific membrane antigen-1007 positron emission tomography/ computed tomography (18F-PSMA-1007 PET/CT) revealed weak physiological PSMA accumulation in the prostate and strong accumulation not only in the internal iliac lymph node but also in the two obturator lymph nodes that could not be detected with conventional CT or magnetic resonance imaging. Prostatic re-biopsy revealed no prostate malignancy. Under the diagnosis of oligometastases in the pelvic lymph nodes, the patient underwent laparoscopic pelvic lymph node dissection, which revealed lymph node metastases in two obturator lymph nodes and the internal iliac lymph node, corresponding to the PSMA accumulation sites. The patient experienced at least 7 months of recurrence-free duration without additional treatment. CONCLUSION: This study indicates a novel approach to oligometastatic CRPC by means of accurate staging with 18F-PSMA-1007 PET/CT.

Understanding the Origin of Low-Energy Operation Characteristics for Cr2Ge2Te6 Phase-Change Material: Enhancement of Thermal Efficiency in the High-Scaled Memory Device.

Data recording based on the phase transition between amorphous and crystalline phases in a phase-change material (PCM) generally consumes a large amount of operation energy. Heat confinement and scaling down of the contact area between the PCM and electrode are effective strategies for reducing the operation energy in the memory device. Contrary to conventional PCM, such as Ge-Sb-Te compounds (GST), Cr2Ge2Te6 (CrGT) exhibits low thermal conductivity and low-energy memory operation characteristics even in a relatively large contact area. Herein, we show that the operation energy of the CrGT-based memory device is greatly reduced by scaling down. Based on the present results, an operation energy at subpico J order, which was achieved using carbon nanotubes or graphene nanoribbon in the GST-based device, can be realized in the contact area comparable to the product level in the CrGT-based device. The numerical simulation suggests that small thermal and electrical conductivities enhance the thermal efficiency, resulting in a small operation energy for amorphization. It was also found that the residual metastable phase after the amorphization process increased the operation energy for crystallization by the simulation. In other words, these results indicate that further small operation energy can be realized in the CrGT-based device by reducing the metastable phase volume.

Long-term outcomes after discontinuing biological drugs and tofacitinib in patients with rheumatoid arthritis: A prospective cohort study.

OBJECTIVE: This study examined long-term outcomes of biological disease-modifying antirheumatic drugs (bDMARDs) and tofacitinib discontinuation in patients with rheumatoid arthritis (RA). METHODS: Ninety-seven RA patients who desired drug discontinuation after sustained remission or low disease activity for at least 48 weeks due to stable treatment with biological drugs or tofacitinib were enrolled into this study. All patients were prospectively followed until disease flare or the end of the study. Discontinued drugs (previous drugs) were reintroduced to treat flares. RESULTS: Following bDMARD/tofacitinib discontinuation (mean follow-up, 2.1 years; standard deviation, 2.0), disease flare occurred at a crude incidence rate of 0.36 per person-year. The median time to flare was 1.6 years (95% confidence interval [CI] 0.9-2.6), and the cumulative flare probability was estimated to be 45% at 1 year, 64% at 3 years, and 80% at 5 years. No or little radiological progression was shown in 87.1% of patients who maintained remission for 3 years. A Fine‒Gray competing risk regression analysis showed that predictive factors for a flare were longer RA duration at the start of bDMARD/tofacitinib treatment, previous failure of treatment with bDMARDs, and a shorter period of remission or low disease activity before drug discontinuation. Type of discontinued drug was not identified as a predictive factor after adjusting for other predictor variables. Restarting previous treatment regimens led to rapidly regaining disease control in 89% of flare patients within 1 month. CONCLUSION: Discontinuation of bDMARD/tofacitinib may be a feasible strategy in RA patients, especially patients with early treated and longer-controlled RA. Flares are manageable in most RA patients and radiological progression is rare for at least 3 years in patients with sustained remission after bDMARD/tofacitinib discontinuation.

Pulmonary actinomycosis mimicking lung cancer on 18F-fluorodeoxyglucose positron emission tomography: a case report.

BACKGROUND: Pulmonary actinomycosis is a chronic disease characterized by abscess formation, draining sinuses, fistulae, and tissue fibrosis. It can mimic other conditions, particularly malignant and granulomatous diseases, and is perhaps extremely challenging to diagnose. CASE PRESENTATION: A 64-year-old Japanese man presented with 6-week history of a painful solid lump in the chest wall. Chest computed tomography scan revealed a mass-like consolidation in the left upper lobe, with rib erosion and direct extension into the anterior chest wall. 18F-fluorodeoxyglucose positron emission tomography scan showed increased metabolic activity in the mass, which is indicative of primary lung cancer. The bronchoscopy and computed tomography scan-guided transthoracic biopsy results were considered nondiagnostic. Finally, the patient was diagnosed with pulmonary actinomycosis via surgical resection. He completed an 8-week course of antibiotic therapy and experienced no recurrence. CONCLUSIONS: There is no difference in positron emission tomography/computed tomography scan findings between actinomycosis and malignancy. Therefore, pulmonary actinomycosis should be considered in the differential diagnosis of cases involving intensive activity on 18F-fluorodeoxyglucose positron emission tomography scan.