Correlation between genomic index lesions and mpMRI and 68Ga-PSMA-PET/CT imaging features in primary prostate cancer.

Magnetic resonance imaging (MRI) and prostate specific membrane antigen (PSMA)- positron emission tomography (PET)/computed tomography (CT)-imaging of prostate cancer (PCa) are emerging techniques to assess the presence of significant disease and tumor progression. It is not known, however, whether and to what extent lesions detected by these imaging techniques correlate with genomic features of PCa. The aim of this study was therefore to define a genomic index lesion based on chromosomal copy number alterations (CNAs) as marker for tumor aggressiveness in prostate biopsies in direct correlation to multiparametric (mp) MRI and 68Ga-PSMA-PET/CT imaging features. CNA profiles of 46 biopsies from five consecutive patients with clinically high-risk PCa were obtained from radiologically suspicious and unsuspicious areas. All patients underwent mpMRI, MRI/TRUS-fusion biopsy, 68Ga-PSMA-PET/CT and a radical prostatectomy. CNAs were directly correlated to imaging features and radiogenomic analyses were performed. Highly significant CNAs (≥10 Mbp) were found in 22 of 46 biopsies. Chromosome 8p, 13q and 5q losses were the most common findings. There was an strong correspondence between the radiologic and the genomic index lesions. The radiogenomic analyses suggest the feasibility of developing radiologic signatures that can distinguish between genomically more or less aggressive lesions. In conclusion, imaging features of mpMRI and 68Ga-PSMA-PET/CT can guide to the genomically most aggressive lesion of a PCa. Radiogenomics may help to better differentiate between indolent and aggressive PCa in the future.

Genomic features of renal cell carcinoma with venous tumor thrombus.

A venous tumor thrombus (VTT) is a potentially lethal complication of renal cell carcinoma (RCC) but virtually nothing is known about the underlying natural history. Based on our observation that venous thrombi contain significant numbers of viable tumor cells, we applied multiregion whole exome sequencing to a total of 37 primary tumor and VTT samples including normal tissue specimens from five consecutive patients. Our findings demonstrate mutational heterogeneity between primary tumor and VTT with 106 of 483 genes (22%) harboring functional SNVs and/or indels altered in either primary tumor or thrombus. Reconstruction of the clonal phylogeny showed clustering of tumor samples and VTT samples, respectively, in the majority of tumors. However, no new subclones were detected suggesting that pre-existing subclones of the primary tumor drive VTT formation. Importantly, we found several lines of evidence for "BRCAness" in a subset of tumors. These included mutations in genes that confer "BRCAness", a mutational signature and an increase of small indels. Re-analysis of SNV calls from the TCGA KIRC-US cohort confirmed a high frequency of the "BRCAness" mutational signature AC3 in clear cell RCC. Our findings warrant further pre-clinical experiments and may lead to novel personalized therapies for RCC patients.

Increased intraepithelial CD3+ T-lymphocytes and high PD-L1 expression on tumor cells are associated with a favorable prognosis in esophageal squamous cell carcinoma and allow prognostic immunogenic subgrouping.

Esophageal squamous cell carcinoma (ESCC) is the most common esophageal cancer associated with poor prognosis and additional therapeutic strategies must be implemented to optimize ESCC treatment. Meanwhile, the important biologic role and potential prognostic and therapeutic implications of a tumors immunologic microenvironment (IM) have been recognized in various cancers.In order to investigate the contexture and the prognostic relevance of the IM in ESCC, we immunohistochemically evaluated the extent of overall/intraepithelial TILs (CD3+/CD8+) and of PD-1 / PD-L1 expression in a cohort of 125 therapy-naive ESCCs, additionally assessing PD-L1 copy number status via fluorescence in-situ hybridization.High intraepithelial CD3+ TILs (CD3ihigh) and high PD-L1 expression on tumor cells (PD-L1high) were each significantly associated with improved overall- (OS) (CD3+: p = 0.019; PD-L1: p = 0.028), disease specific- (DSS) (CD3+: p = 0.05; PD-L1: p = 0.006) and disease free survival (DFS) (CD3+: p = 0.009; PD-L1: p < 0.001). CD3ihigh- and PD-L1high cases were significantly associated with one another (p < 0.001). Subgrouping of ESCC revealed decreased OS (p = 0.031), DSS (p = 0.012) and DFS (p < 0.001) for CD3ilow/PD-L1low cancers.Our data not only associate CD3ihigh- and PD-L1high ESCC with a beneficial outcome, but also demonstrate PD-L1high- and CD3ihigh status to be closely intertwined. Furthermore, our study demarcates a prognostically unfavorable, "non-immunoreactive" CD3ilow / PD-L1low ESCC-subgroup, potentially forming the basis for an immune-based stratification of ESCC.

Intraindividual Comparison of 18F-PSMA-1007 PET/CT, Multiparametric MRI, and Radical Prostatectomy Specimens in Patients with Primary Prostate Cancer: A Retrospective, Proof-of-Concept Study.

68Ga-prostate-specific membrane antigen (PSMA)-11 PET/CT represents an advanced method for the staging of primary prostate cancer (PCa) and diagnosis of recurrent or metastatic PCa. However, because of the narrow availability of 68Ga the development of alternative tracers is of high interest. The objective of this study was to examine the value of the new PET tracer 18F-PSMA-1007 for the staging of local disease by comparing it with multiparametric MRI (mpMRI) and radical prostatectomy (RP) histopathology. Methods: In 2016, 18F-PSMA-1007 PET/CT was performed in 10 men with biopsy-confirmed high-risk PCa. Nine patients underwent mpMRI in the process of primary diagnosis. Consecutively, RP was performed in all 10 men. Agreement analysis was performed retrospectively. PSMA staining was added for representative sections in RP specimen slices. Localization and agreement analysis of 18F-PSMA-1007 PET/CT, mpMRI, and RP specimens was performed by dividing the prostate into 38 sections as described in the prostate imaging reporting and data system (PI-RADS) (version 2). Sensitivity, specificity, positive predictive values, negative predictive values (NPVs), and accuracy were calculated for total and near-total agreement. Results:18F-PSMA-1007 PET/CT had an NPV of 68% and an accuracy of 75%, and mpMRI had an NPV of 88% and an accuracy of 73% for total agreement. Near-total agreement analysis resulted in an NPV of 91% and an accuracy of 93% for 18F-PSMA-1007 PET/CT and 91% and 87% for mpMRI, respectively. Retrospective combination of mpMRI and PET/CT had an accuracy of 81% for total and 93% for near-total agreement. Conclusion: Comparison with RP histopathology demonstrates that 18F-PSMA-1007 PET/CT is promising for accurate local staging of PCa.

A Novel Grading System Based on Tumor Budding and Cell Nest Size Is a Strong Predictor of Patient Outcome in Esophageal Squamous Cell Carcinoma.

The determination of prognosis in patients with esophageal squamous cell carcinoma (ESCC) is primarily based on staging according to the TNM-classification, whereas conventional grading is of minor clinical importance because of its deficiencies in prognostic patient stratification. Recently, a novel, highly prognostic grading scheme based on budding activity and cell nest size has been proposed for squamous cell carcinoma (SCC) of both pulmonary as well as oral origin. In order to investigate the utility and transferability of this approach to ESCC, we evaluated budding activity and cell nest size, as well as other histomorphologic characteristics, in a cohort of 135 primarily resected tumors and correlated the results with clinicopathologic and outcome parameters. High budding activity and small cell nest size showed a strong association with reduced overall, disease-specific, and disease-free survival (P<0.001, respectively) in ESCC. The combination of both markers in a 3-step grading system showed excellent prognostic separation of well-differentiated (G1), moderately differentiated (G2), and poorly differentiated (G3) carcinomas (P<0.001). The hazard ratio for disease-free survival in multivariate analysis under inclusion of stage was 2.97 for G2 and 5.42 for G3 ESCC (P<0.001). World Health Organization-based grading had no prognostic impact. Taken together, our data prove the value of tumor budding and cell nest size as excellent outcome predictors in ESCC and validate the utility of a previously established grading scheme proposed for oral and pulmonary SCC in this tumor entity. Ultimately, these combined efforts may result in a universal grading system for SCC regardless of the site of origin.

The Value of PSA Density in Combination with PI-RADS™ for the Accuracy of Prostate Cancer Prediction.

PURPOSE: Multiparametric magnetic resonance imaging has an emerging role in prostate cancer diagnostics. In addition, clinical information is a reliable predictor of significant prostate cancer. We analyzed whether the negative predictive value of multiparametric magnetic resonance imaging to rule out significant prostate cancer could be improved using clinical factors, especially prostate specific antigen density. MATERIALS AND METHODS: A total of 1,040 consecutive men with suspicion of prostate cancer underwent multiparametric magnetic resonance imaging first, followed by transperineal systematic and magnetic resonance imaging-transrectal ultrasound fusion guided biopsy. Logistic regression analyses were performed to test different clinical factors as predictors of significant prostate cancer and build nomograms. To simplify these nomograms for clinical use patients were stratified into 3 prostate specific antigen density groups, including group 1-less than 0.07, group 2-0.07 to 0.15 and group 3-greater than 0.15 ng/ml/ml. After stratification we calculated the negative predictive value of a PI-RADS (Prostate Imaging Reporting and Data System) Likert score of less than 3. Significant prostate cancer was defined as a Gleason score of 3 + 4 or greater. High grade prostate cancer was defined as a Gleason score of 4 + 3 or greater. RESULTS: Overall 451 men were diagnosed with significant prostate cancer, including 187 with a Gleason score of 4 + 3 or greater. On ROC curve analyses the predictive power of the developed nomogram for significant prostate cancer showed a higher AUC than that of PI-RADS alone (0.79 vs 0.75, p <0.001). The negative predictive value of harboring significant prostate cancer increased in men with unsuspicious magnetic resonance imaging from 79% up to 89% when prostate specific antigen density was 0.15 ng/ml/ml or less. In the repeat biopsy setting the negative predictive value of significant prostate cancer increased from 83% to 93%. The negative predictive value to harbor high grade prostate cancer increased from 92% up to 98% in the entire cohort. CONCLUSIONS: Using prostate specific antigen density combined with multiparametric magnetic resonance imaging improved the negative predictive value of PI-RADS scoring. By increasing the probability of ruling out significant prostate cancer approximately 20% of unnecessary biopsies could be avoided safely.

Combined Clinical Parameters and Multiparametric Magnetic Resonance Imaging for Advanced Risk Modeling of Prostate Cancer-Patient-tailored Risk Stratification Can Reduce Unnecessary Biopsies.

BACKGROUND: Multiparametric magnetic resonance imaging (mpMRI) is gaining widespread acceptance in prostate cancer (PC) diagnosis and improves significant PC (sPC; Gleason score≥3+4) detection. Decision making based on European Randomised Study of Screening for PC (ERSPC) risk-calculator (RC) parameters may overcome prostate-specific antigen (PSA) limitations. OBJECTIVE: We added pre-biopsy mpMRI to ERSPC-RC parameters and developed risk models (RMs) to predict individual sPC risk for biopsy-naïve men and men after previous biopsy. DESIGN, SETTING, AND PARTICIPANTS: We retrospectively analyzed clinical parameters of 1159 men who underwent mpMRI prior to MRI/transrectal ultrasound fusion biopsy between 2012 and 2015. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Multivariate regression analyses were used to determine significant sPC predictors for RM development. The prediction performance was compared with ERSPC-RCs, RCs refitted on our cohort, Prostate Imaging Reporting and Data System (PI-RADS) v1.0, and ERSPC-RC plus PI-RADSv1.0 using receiver-operating characteristics (ROCs). Discrimination and calibration of the RM, as well as net decision and reduction curve analyses were evaluated based on resampling methods. RESULTS AND LIMITATIONS: PSA, prostate volume, digital-rectal examination, and PI-RADS were significant sPC predictors and included in the RMs together with age. The ROC area under the curve of the RM for biopsy-naïve men was comparable with ERSPC-RC3 plus PI-RADSv1.0 (0.83 vs 0.84) but larger compared with ERSPC-RC3 (0.81), refitted RC3 (0.80), and PI-RADS (0.76). For postbiopsy men, the novel RM's discrimination (0.81) was higher, compared with PI-RADS (0.78), ERSPC-RC4 (0.66), refitted RC4 (0.76), and ERSPC-RC4 plus PI-RADSv1.0 (0.78). Both RM benefits exceeded those of ERSPC-RCs and PI-RADS in the decision regarding which patient to receive biopsy and enabled the highest reduction rate of unnecessary biopsies. Limitations include a monocentric design and a lack of PI-RADSv2.0. CONCLUSIONS: The novel RMs, incorporating clinical parameters and PI-RADS, performed significantly better compared with RMs without PI-RADS and provided measurable benefit in making the decision to biopsy men at a suspicion of PC. For biopsy-naïve patients, both our RM and ERSPC-RC3 plus PI-RADSv1.0 exceeded the prediction performance compared with clinical parameters alone. PATIENT SUMMARY: Combined risk models including clinical and imaging parameters predict clinically relevant prostate cancer significantly better than clinical risk calculators and multiparametric magnetic resonance imaging alone. The risk models demonstrate a benefit in making a decision about which patient needs a biopsy and concurrently help avoid unnecessary biopsies.

TOP: Prospective Evaluation of a Volume Based, Computer Assisted Method for Transperineal Optimized Prostate Biopsy.

OBJECTIVE: This study is a prospective evaluation of a volume-based, computer-assisted method for transperineal optimized prostate (TOP) biopsy. The TOP algorithm automates core planning for systematic prostate biopsies using the 3-dimensional organ contour and an alterable volume for tumors to be excluded. SUBJECTS AND METHODS: MRI-transrectal ultrasound fusion biopsy with MRI-targeted biopsies (TBs) and systematic-TOP biopsies were performed on 172 men between October 2013 and March 2014. Systematic biopsies were placed according to TOP for detection of tumor volumes >0.5 mL with a minimum of 80% organ coverage in prostates up to 50 mL (70% in larger organs). RESULTS: Median 24 TOP cores and 3 MRI-TBs have been placed. Prostate cancer (PCa) was detected in 112 of 172 (65%) of men; TOP detected 109 (97%) and TB 62 (55%). Significant cancer (Gleason score ≥7) was detected in 75 (44%) of men and of these TOP detected 73 of 75 (97%) and TB 51 of 75 (68%). Overall, systematic-TOP sampling significantly outperformed TB for the detection of both, all PCa as well as significant PCa (p < 0.0001, p = 0.0005). CONCLUSION: The TOP method is innovative by integrating the individual prostate volume and PCa volume detection thresholds. In the present cohort, it diagnosed more significant tumors than TB alone. However, at the same time, more low-risk tumors are detected.

Local recurrence of prostate cancer after radical prostatectomy is at risk to be missed in 68Ga-PSMA-11-PET of PET/CT and PET/MRI: comparison with mpMRI integrated in simultaneous PET/MRI.

PURPOSE: The positron emission tomography (PET) tracer 68Ga-PSMA-11, targeting the prostate-specific membrane antigen (PSMA), is rapidly excreted into the urinary tract. This leads to significant radioactivity in the bladder, which may limit the PET-detection of local recurrence (LR) of prostate cancer (PC) after radical prostatectomy (RP), developing in close proximity to the bladder. Here, we analyze if there is additional value of multi-parametric magnetic resonance imaging (mpMRI) compared to the 68Ga-PSMA-11-PET-component of PET/CT or PET/MRI to detect LR. METHODS: One hundred and nineteen patients with biochemical recurrence after prior RP underwent both hybrid 68Ga-PSMA-11-PET/CTlow-dose (1 h p.i.) and -PET/MRI (2-3 h p.i.) including a mpMRI protocol of the prostatic bed. The comparison of both methods was restricted to the abdomen with focus on LR (McNemar). Bladder-LR distance and recurrence size were measured in axial T2w-TSE. A logistic regression was performed to determine the influence of these variables on detectability in 68Ga-PSMA-11-PET. Standardized-uptake-value (SUVmean) quantification of LR was performed. RESULTS: There were 93/119 patients that had at least one pathologic finding. In addition, 18/119 Patients (15.1%) were diagnosed with a LR in mpMRI of PET/MRI but only nine were PET-positive in PET/CT and PET/MRI. This mismatch was statistically significant (p = 0.004). Detection of LR using the PET-component was significantly influenced by proximity to the bladder (p = 0.028). The PET-pattern of LR-uptake was classified into three types (1): separated from bladder; (2): fuses with bladder, and (3): obliterated by bladder). The size of LRs did not affect PET-detectability (p = 0.84), mean size was 1.7 ± 0.69 cm long axis, 1.2 ± 0.46 cm short-axis. SUVmean in nine men was 8.7 ± 3.7 (PET/CT) and 7.0 ± 4.2 (PET/MRI) but could not be quantified in the remaining nine cases (obliterated by bladder). CONCLUSION: The present study demonstrates additional value of hybrid 68Ga-PSMA-11-PET/MRI by gaining complementary diagnostic information compared to the 68Ga-PSMA-11-PET/CTlow-dose for patients with LR of PC.

Multicentre evaluation of targeted and systematic biopsies using magnetic resonance and ultrasound image-fusion guided transperineal prostate biopsy in patients with a previous negative biopsy.

OBJECTIVES: To evaluate the detection rates of targeted and systematic biopsies in magnetic resonance imaging (MRI) and ultrasound (US) image-fusion transperineal prostate biopsy for patients with previous benign transrectal biopsies in two high-volume centres. PATIENTS AND METHODS: A two centre prospective outcome study of 487 patients with previous benign biopsies that underwent transperineal MRI/US fusion-guided targeted and systematic saturation biopsy from 2012 to 2015. Multiparametric MRI (mpMRI) was reported according to Prostate Imaging Reporting and Data System (PI-RADS) Version 1. Detection of Gleason score 7-10 prostate cancer on biopsy was the primary outcome. Positive (PPV) and negative (NPV) predictive values including 95% confidence intervals (95% CIs) were calculated. Detection rates of targeted and systematic biopsies were compared using McNemar's test. RESULTS: The median (interquartile range) PSA level was 9.0 (6.7-13.4) ng/mL. PI-RADS 3-5 mpMRI lesions were reported in 343 (70%) patients and Gleason score 7-10 prostate cancer was detected in 149 (31%). The PPV (95% CI) for detecting Gleason score 7-10 prostate cancer was 0.20 (±0.07) for PI-RADS 3, 0.32 (±0.09) for PI-RADS 4, and 0.70 (±0.08) for PI-RADS 5. The NPV (95% CI) of PI-RADS 1-2 was 0.92 (±0.04) for Gleason score 7-10 and 0.99 (±0.02) for Gleason score ≥4 + 3 cancer. Systematic biopsies alone found 125/138 (91%) Gleason score 7-10 cancers. In patients with suspicious lesions (PI-RADS 4-5) on mpMRI, systematic biopsies would not have detected 12/113 significant prostate cancers (11%), while targeted biopsies alone would have failed to diagnose 10/113 (9%). In equivocal lesions (PI-RADS 3), targeted biopsy alone would not have diagnosed 14/25 (56%) of Gleason score 7-10 cancers, whereas systematic biopsies alone would have missed 1/25 (4%). Combination with PSA density improved the area under the curve of PI-RADS from 0.822 to 0.846. CONCLUSION: In patients with high probability mpMRI lesions, the highest detection rates of Gleason score 7-10 cancer still required combined targeted and systematic MRI/US image-fusion; however, systematic biopsy alone may be sufficient in patients with equivocal lesions. Repeated prostate biopsies may not be needed at all for patients with a low PSA density and a negative mpMRI read by experienced radiologists.

Aggressive systemic mastocytosis of the liver with cholangitis.

Mastocytosis is a clonal, neoplastic mast cell proliferation, which is in most cases restricted to the skin (cutaneous mastocytosis), but may infiltrate other organs as well (systemic mastocytosis). Involvement of the liver by a systemic mastocytosis with impairment of liver function has been recognized as sign of an aggressive course of disease (C-finding). This article presents a case of aggressive systemic mastocytosis in a 26-year-old male patient with involvement of the liver mimicking primary sclerosing cholangitis. By histology we could demonstrate multifocal clusters of atypical mast cells infiltrating portal tracts in intimate contact with bile ducts as the cause of cholangitis and liver fibrosis.

Influence of different modifications of a calcium phosphate cement on resorption and new bone formation: an in vivo study in the minipig.

Calcium phosphate cements (CPCs) are established in surgery as temporary bone replacement materials. The most common and important class of CPC, transformed into nanocrystalline hydroxyapatite after setting, is characterized by good biocompatibility and osteoconductivity. However, acceleration of remodelling is in the focus of ongoing research. In the present study, the bone healing efficacy of Biocement D (BioD) modified with mineralized collagen alone (BioD/coll) or in combination with osteocalcin (BioD/coll/OC), O-phospho-L-serine (BioD/coll/PS), sodium citrate (BioD/coll/cit), and polylactide (BioD/coll/PL), respectively, was evaluated in a large animal model. Resorption of the bone substitutes and new bone formation were studied in cyst-like jaw defects of minipigs after filling with the unmodified BioD and the modified BioD variants, respectively. Histomorphometric analysis revealed small differences between the different cement types with respect to resorption. However, new bone formation was improved in case of defects repaired with BioD/coll/OC and BioD/coll/PS and slightly improved in case of BioD/coll and BioD/coll/PL.

Trabectedin in the neoadjuvant treatment of high-grade pleomorphic sarcoma: report of a rare case and literature review.

Background. Pleomorphic sarcoma is an aggressive soft tissue sarcoma. In patients with high-risk extremity sarcomas, the significant survival benefits conferred by an intense regimen of neoadjuvant chemoradiotherapy and surgery were reported. To our knowledge, this is the first report in the literature of the neoadjuvant use of trabectedin in a patient with high-grade pleomorphic sarcoma, ineligible for standard neoadjuvant combination therapy with an anthracycline-based regimen. Case Presentation. Here we present a 58-year-old White male with a large tumor in the left thigh, but with no signs of metastases. Owing to the history of severe heart attack, three cycles of neoadjuvant trabectedin were administrated to achieve surgically wide margins. After two cycles, an 18F-FDG-PET showed a large proportion of the central tumor area was without metabolic activity. According to RECIST and Choi criteria, the tumor was stable. After the third cycle of trabectedin, the patient underwent a complete resection, which revealed completely necrotic high-grade pleomorphic sarcoma (stage pT2b), with only a small vital area. Conclusion. The present paper on a promising treatment with neoadjuvant trabectedin of patients with high-grade pleomorphic sarcoma might suggest that such treatment approach may provide a greater chance of cure and survival of such patients.

HIF-1α is a protective factor in conditional PHD2-deficient mice suffering from severe HIF-2α-induced excessive erythropoiesis.

Erythropoiesis must be tightly balanced to guarantee adequate oxygen delivery to all tissues in the body. This process relies predominantly on the hormone erythropoietin (EPO) and its transcription factor hypoxia inducible factor (HIF). Accumulating evidence suggests that oxygen-sensitive prolyl hydroxylases (PHDs) are important regulators of this entire system. Here, we describe a novel mouse line with conditional PHD2 inactivation (cKO P2) in renal EPO producing cells, neurons, and astrocytes that displayed excessive erythrocytosis because of severe overproduction of EPO, exclusively driven by HIF-2α. In contrast, HIF-1α served as a protective factor, ensuring survival of cKO P2 mice with HCT values up to 86%. Using different genetic approaches, we show that simultaneous inactivation of PHD2 and HIF-1α resulted in a drastic PHD3 reduction with consequent overexpression of HIF-2α-related genes, neurodegeneration, and lethality. Taken together, our results demonstrate for the first time that conditional loss of PHD2 in mice leads to HIF-2α-dependent erythrocytosis, whereas HIF-1α protects these mice, providing a platform for developing new treatments of EPO-related disorders, such as anemia.

Early onset systemic lupus erythematosus: differential diagnoses, clinical presentation, and treatment options.

Juvenile systemic lupus erythematosus is a rare multisystemic autoimmune disease with variable clinical manifestations, and disease onset before 16 years of age. Patients younger than 5 years are rarely affected and the age of onset may contribute to the course of disease in terms of clinical presentation, organ involvement, and serological findings. Here, we report two exemplary early-onset SLE patients, a 28-month-old patient with WHO class IIB kidney disease, arthritis, and a typical antibody constellation and an 11-month-old infant that presented with microcytic anemia, leukocytosis, arthritis, fasciitis, fatty liver disease, protein losing enteropathy, edema, and minimal change glomerulonephritis. Epidemiologic and clinical features of early-onset SLE compared to other forms of SLE are given and differential diagnoses and treatment options are discussed.

Chronic granulomatous disease (CGD) mimicking neoplasms: a suspected mediastinal teratoma unmasking as thymic granulomas due to X-linked CGD, and 2 related cases.

Patients with chronic granulomatous disease (CGD) suffer from severe bacterial and fungal infections and deregulated inflammation, which are often associated with granuloma formation. We describe a 2-year-old boy who was seemingly healthy at the age of 1 year when a conventional chest radiograph was taken to exclude pulmonary aspiration of a piece of apple. Incidentally, a space-occupying mediastinal mass was revealed that was further evaluated by magnetic resonance imaging. Varying solid and also cystic, septated parts of the mass could be discerned and it was considered to be a teratoma. Removal of the mass by surgery was arduous because of adhesiveness to surrounding areas and led to severe complications. Unexpectedly, histopathologic examination revealed massive acute granulomatous inflammation with liquefied thymic cysts. X-linked CGD was subsequently diagnosed by a dihydrorhodamine 123 assay and sequencing of the CYBB gene (hotspot mutation c.742-743insA). This is the third example that we are aware of, where CGD granulomas were mistaken for neoplasms. The other 2 patients were initially believed to have tumors of the stomach and the urinary bladder, respectively. All patients initially received inadequate treatment. We discuss possible strategies to avoid such tragic confusions.