Appendiceal mucocele formation can be induced by mechanical obstruction due to various reasons; In very rare cases, mucosal prolapse of the appendix can also cause mucocele. We first present the case of a 38-year-old woman who was diagnosed with appendiceal mucocele associated with appendiceal mucosal prolapse. The lesion was first found by colonoscopy and treated surgically. On examining the specimen, it revealed a dilated lumen containing mucinous fluid at the proximal portion, a polypoid mass at the mid portion, and a slightly dilated distal portion filled with mucoid material. But there was no histologic evidence of polyp. We report the first case of mucosal prolapse of the appendix resulting in mucocele with a review of the concepts of prolapse.

Background/Aims: Caudal type homeobox (CDX)-1 and -2 are reportedly involved in the development and progression of gastric cancer (GC). Although there are several reports on the prognostic significance of CDX-2 expression in GC, it remains controversial. In this study, we sought to validate the prognostic value of CDX-1 and -2 expression according to the histologic and molecular subtypes of GC. Methods: In total, 1,158 cases of advanced GC were investigated using immunohistochemical staining and tissue microarrays for CDX-1 and -2 expression, and survival analysis was performed according to different histological and molecular subtypes. Results: Of the 915 GCs with CDX-1 expression, 163 (17.8%) were Epstein-Barr virus (EBV)-positive or mismatch repair deficient (MMR-d), and the remaining 752 (82.2%) were EBV-negative or MMR-proficient (MMR-p). Of the 1,008 GCs with CDX-2 expression, 177 (17.5%) were EBV-positive or MMR-d, and the remaining 831 (82.5%) were EBV-negative or MMR-p. In the EBV-positive and MMR-d groups, CDX expression had no relationship with patient outcomes.In the EBV-negative and MMR-p groups, 404 (53.7%) and 523 (62.9%) samples were positive for CDX-1 and CDX-2 expression, respectively. Survival analysis demonstrated that CDX-1 and CDX-2 expression in all patients was correlated with favorable outcomes in terms of overall survival (multivariate analysis; p=0.018 and p=0.028, respectively). In the subgroup analysis, CDX-1 expression and CDX-2 expression were associated with favorable outcomes in EBV-negative and MMR-p intestinal (p=0.015 and p=0.010), and mixed and diffuse-type (p=0.019 and p=0.042) GCs, respectively. Conclusions The expression of CDX-1 and CDX-2 is a favorable prognostic factor in EBVnegative, MMR-p advanced GC.

Background/Aims: Caudal type homeobox (CDX)-1 and -2 are reportedly involved in the development and progression of gastric cancer (GC). Although there are several reports on the prognostic significance of CDX-2 expression in GC, it remains controversial. In this study, we sought to validate the prognostic value of CDX-1 and -2 expression according to the histologic and molecular subtypes of GC. Methods: In total, 1,158 cases of advanced GC were investigated using immunohistochemical staining and tissue microarrays for CDX-1 and -2 expression, and survival analysis was performed according to different histological and molecular subtypes. Results: Of the 915 GCs with CDX-1 expression, 163 (17.8%) were Epstein-Barr virus (EBV)-positive or mismatch repair deficient (MMR-d), and the remaining 752 (82.2%) were EBV-negative or MMR-proficient (MMR-p). Of the 1,008 GCs with CDX-2 expression, 177 (17.5%) were EBV-positive or MMR-d, and the remaining 831 (82.5%) were EBV-negative or MMR-p. In the EBV-positive and MMR-d groups, CDX expression had no relationship with patient outcomes.In the EBV-negative and MMR-p groups, 404 (53.7%) and 523 (62.9%) samples were positive for CDX-1 and CDX-2 expression, respectively. Survival analysis demonstrated that CDX-1 and CDX-2 expression in all patients was correlated with favorable outcomes in terms of overall survival (multivariate analysis; p=0.018 and p=0.028, respectively). In the subgroup analysis, CDX-1 expression and CDX-2 expression were associated with favorable outcomes in EBV-negative and MMR-p intestinal (p=0.015 and p=0.010), and mixed and diffuse-type (p=0.019 and p=0.042) GCs, respectively. Conclusions The expression of CDX-1 and CDX-2 is a favorable prognostic factor in EBVnegative, MMR-p advanced GC.

Objective: The RAD51 assay is a recently developed functional assay for homologous recombination deficiency (HRD) that reflects real-time HRD status. We aimed to identify the applicability and predictive value of RAD51 immunohistochemical expression in pre- and post-neoadjuvant chemotherapy (NAC) samples of ovarian high-grade serous carcinoma (HGSC). Methods: We evaluated the immunohistochemical expression of RAD51/geminin/γH2AX in ovarian HGSC before and after NAC. Results: In pre-NAC tumors (n=51), 74.5% (39/51) showed at least 25% of γH2AX-positive tumor cells, suggesting endogenous DNA damage. The RAD51-high group (41.0%, 16/39) showed significantly worse progression-free survival (PFS) compared to the RAD51-low group (51.3%, 20/39) (p=0.032). In post-NAC tumors (n=50), the RAD51-high group (36.0%, 18/50) showed worse PFS (p=0.013) and tended to present worse overall survival (p=0.067) compared to the RAD51-low group (64.0%, 32/50). RAD51-high cases were more likely to progress than RAD51-low cases at both 6 months and 12 months (p=0.046 and p=0.019, respectively). Of 34 patients with matched pre- and post-NAC RAD51 results, 44% (15/34) of pre-NAC RAD51 results were changed in the post-NAC tissue, and the RAD51 high-to-high group showed the worst PFS, while the low-to-low group showed the best PFS (p=0.031). Conclusion High RAD51 expression was significantly associated with worse PFS in HGSC, and post-NAC RAD51 status showed higher association than pre-NAC RAD51 status. Moreover, RAD51 status can be evaluated in a significant proportion of treatment-naïve HGSC samples. As RAD51 status dynamically changes, sequential follow-up of RAD51 status might reflect the biological behavior of HGSCs.

Kawasaki disease (KD) is a systemic vasculitis associated with various clinical manifestations and complications, such as gastrointestinal abnormalities. We report a 3-year-old boy who presented with hematemesis and diffuse gastroduodenal ulcerations complicating KD. He received standard medical therapy for the disease and gastric ulcer, which showed effect after a few days. Although rare, peptic ulcers should be considered a complication of KD to ensure early diagnosis and treatment as it may cause severe morbidity.
Child ; Child, Preschool ; Early Diagnosis ; Endoscopy ; Hematemesis ; Humans ; Male ; Mucocutaneous Lymph Node Syndrome ; Peptic Ulcer ; Stomach Ulcer ; Systemic Vasculitis

Objective: The Montreal Cognitive Assessment (MoCA) is recommended for assessing general cognition in Parkinson’s disease (PD). Several cutoffs of MoCA scores for diagnosing PD with cognitive impairment (PD-CI) have been proposed, with varying sensitivity and specificity. This study investigated the utility of machine learning algorithms using MoCA cognitive domain scores for improving diagnostic performance for PD-CI. Methods: In total, 2,069 MoCA results were obtained from 397 patients with PD enrolled in the Parkinson’s Progression Markers Initiative database with a diagnosis of cognitive status based on comprehensive neuropsychological assessments. Using the same number of MoCA results randomly sampled from patients with PD with normal cognition or PD-CI, discriminant validity was compared between machine learning (logistic regression, support vector machine, or random forest) with domain scores and a cutoff method. Results: Based on cognitive status classification using a dataset that permitted sampling of MoCA results from the same individual (n = 221 per group), no difference was observed in accuracy between the cutoff value method (0.74 ± 0.03) and machine learning (0.78 ± 0.03). Using a more stringent dataset that excluded MoCA results (n = 101 per group) from the same patients, the accuracy of the cutoff method (0.66 ± 0.05), but not that of machine learning (0.74 ± 0.07), was significantly reduced. Inclusion of cognitive complaints as an additional variable improved the accuracy of classification using the machine learning method (0.87–0.89). Conclusion Machine learning analysis using MoCA domain scores is a valid method for screening cognitive impairment in PD.

Background: This study aimed to identify the most cost-effective strategy for colorectal cancer screening using the fecal immunochemical test (FIT), focusing on screening initiation age in Korea. Methods: We designed Markov simulation models targeting individuals aged 40 years or older. Twelve strategies combining screening initiation ages (40, 45, or 50 years old), termination ages (80 or no limit), and intervals (1 or 2 years) were modeled, and the most cost-effective strategy was selected. The robustness of the results was confirmed using one-way and probabilistic sensitivity analyses. Furthermore, the cost-effectiveness of the qualitative and quantitative FIT methods was verified using scenario analysis. Results: The 2-year interval strategy with a screening age range of 45–80 years was the most cost-effective (incremental cost-utility ratio = KRW 7,281,646/quality adjusted life years). The most sensitive variables in the results were transition rate from advanced adenoma to local cancer and discount rate. The uncertainty in the model was substantially low. Moreover, strategies starting at the age of 40 years were also cost-effective but considered suboptimal. The scenario analysis showed that there was no significant difference in cost-effectiveness between strategies with various relative screening ratio of quantitative and qualitative method. Conclusion The screening method for advancing the initiation age, as presented in the 2015 revised national screening recommendations, was superior regarding cost-effectiveness. This study provides a new paradigm for the development of a national cancer screening system in Korea, which can be utilized as a scientific basis for economic evaluations.

Objective: Osteomyelitis in patients with diabetic foot has been diagnosed clinically, radiologically, and histologically. However, the accuracy of these diagnostic modalities is not well established. In this study, we histologically reviewed patients who underwent surgical procedures for diabetic foot osteomyelitis and correlated these histological features with radiological findings. Methods: Eighty patients who were clinically diagnosed with diabetic foot osteomyelitis, who underwent surgical treatment between November 2017 and February 2022, were enrolled. Hematoxylin and eosin-stained slides and radiological findings were reviewed. Results: Eighty patients were radiologically examined by magnetic resonance imaging (MRI) (49 cases) and/or 99mTc-hexamethyl-propylene amine oxime-labeled white blood cells single-photon emission computed tomography (SPECT)/computed tomography (CT) (65 cases). MRI findings were suggestive of osteomyelitis in 35 cases (71.4%) and soft tissue inflammation in 46 cases (93.8%). In SPECE/CT, 60 cases (92.3%) and 64 cases (98.4%) showed signs of osteomyelitis and soft tissue inflammation, respectively. Histologically, both bone and soft tissue lesions were found in 32 cases (40%), only bone tissue lesions in seven cases (8.8%), and only soft tissue lesions in 40 cases (50%). The sensitivity and specificity of MRI for osteomyelitis were 83.3% (10/12) and 28.6% (4/14), and that of SPECT/CT was 100.0% (12/12) and 12.5% (2/16), respectively. Moreover, those of by MRI findings for soft tissue inflammation were 90.6% (29/32) and 0% (0/12), while that of SPECT/CT was 97.4% (38/39) and 0% (0/18), respectively. Conclusion For accurate histological diagnosis of diabetic foot osteomyelitis, sufficient specimens should be obtained. White blood cell SPECT/CT seems to be a more sensitive modality than MRI for the detection of osteomyelitis.

Struma ovarii (SO) is a rare ovarian teratoma, which is diagnosed when thyroid tissue accounts for more than 50% of the teratoma. The majority of SO are benign, but malignant tumors have been reported in a small percentage of cases. Five percent of SO cases have been proven to be malignant and, as in the thyroid gland, papillary carcinoma is the most common histotype arising in SO. Because this tumor is rare, there are no guidelines regarding the management of this cancer. Usually, total thyroidectomy followed by radioiodine treatment is the treatment of choice in metastatic malignant struma ovarii, but therapeutic decisions should be made individually based on clinical and pathological data. We recently experienced a case of a 45-year-old woman finally confirmed as malignant struma ovarii with cervical thyroid cancer. Therefore, we present this unique case with a review of the literature.