The Gleason grading system, currently the most powerful prognostic predictor of prostate cancer, is based solely on the tumor’s histological architecture and has high inter-observer variability. We propose an automated Gleason scoring system based on deep neural networks for diagnosis of prostate core needle biopsy samples. To verify its efficacy, the system was trained using 1133 cases of prostate core needle biopsy samples and validated on 700 cases. Further, system-based diagnosis results were compared with reference standards derived from three certified pathologists. In addition, the system’s ability to quantify cancer in terms of tumor length was also evaluated via comparison with pathologist-based measurements. The results showed a substantial diagnostic concordance between the system-grade group classification and the reference standard (0.907 quadratic-weighted Cohen’s kappa coefficient). The system tumor length measurements were also notably closer to the reference standard (correlation coefficient, R = 0.97) than the original hospital diagnoses (R = 0.90). We expect this system to assist pathologists to reduce the probability of over- or under-diagnosis by providing pathologist-level second opinions on the Gleason score when diagnosing prostate biopsy, and to support research on prostate cancer treatment and prognosis by providing reproducible diagnosis based on the consistent standards.

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Background : The Src family kinases (SFKs) are involved in multiple aspects of tumorigenesis, such as, proliferation, migration, and angiogenesis, and are involved in the generation and progression of many types of tumors. Furthermore, dasatinib, a general SFKs inhibitor was recently approved for use in chronic myeloid leukemia. This study was performed to evaluate the expression of Lyn, a member of the SFKs, in osteosarcoma tissues. Methods : One hundred and sixteen patients with osteoblastic osteosarcoma were selected for Lyn expression analysis. The correlation between Lyn expression in tumor sections and patients' clinicopathologic characteristics and the prognostic significance of Lyn expression were evaluated. Results : Lyn was found to be expressed in 52 of the 116 patients (44.8%), and Lyn positive tumor was found to be significantly associated with a lytic tumor pattern on plain radiographs (p = 0.04). Furthermore, those positive for Lyn showed longer metastasis free survival (5-year metastasis free survival, 65.2% for Lyn positive and 46.8% for Lyn negative; p = 0.06), though this was only marginally significant. Conclusions : Lyn was found to be overexpressed in osteosarcoma tissues, and this overexpression was found to be correlated with osteolysis.

Diffuse large B-cell lymphoma (DLBCL) is the most common high-grade B-cell lymphoma found in Korea; it manifests with a variety of cellular morphologies and a high proliferation index. It is difficult to differentiate between DLBCL and Burkitt lymphoma (BL) based on immunohistochemistry, histology, and Epstein-Barr virus infection status owing to the overlap in findings. In this study, we performed comparative morphometric analysis to understand the proportional difference in Ki-67 staining between DLBCL and BL. We analyzed Ki-67-stained slides of 103 DLBCLs and 29 BLs that were pathologically confirmed using a three-tier classification system (negative, 1+, 2+, and 3+) to compare Ki-67 expression between BL and activated B-cell and germinal center B-cell subtypes of DLBCL and DLBCL with high proliferation indices (>90% of 2+ and 3+ cells). Patients with DLBCL were older than those with BL (62.1 versus 51.0 years). The number and proportion of negative cells (passenger and true negative cells) were significantly lower in BLs than those in DLBCLs (337.4, 5.9% versus 690.3, 12.4%). The number and proportion of 3+ cells were significantly higher in BLs than those in DLBCLs (5213.6, 96.3% versus 3132.4, 62.0%). BLs and DLBCLs with a high proliferation index showed similar results as those between BLs and overall DLBCLs. We were able to differentiate BLs and DLBCLs with 98.1% sensitivity and 100.0% specificity using an optimal cut-off of 97.9% of 2+/3+ Ki-67-positive cells. Thus, the Ki-67 labeling index may be a good differential biomarker for DLBCLs and BLs.

Background: There have been several reports of complications of small bowel lymphoma, such as bleeding, obstruction, and perforation, which require emergency surgery. It is hardly showed complication of bleeding and wound dehiscence for diffuse large B cell lymphoma with distal ileum involvement, which needed urgent surgery and medical management. Chemotherapy is also important when treating small bowel lymphoma, but complications such as bleeding and perforation should always be kept in mind.Case presentation: A 65 year-old man with stage III diffuse large B-cell lymphoma of the activated-B cell (ABC) type with distal ileum involvement experienced both intestinal bleeding and perforation during the course of treatment. As the patient was diagnosed with stage III disease, resection before chemotherapy was not considered due to the resulting delay in chemotherapy, which necessitated sufficient tissue healing. Conclusion: As shown in this case, complications such as bleeding and perforation should always be considered for the treatment of small bowel lymphoma, and surgery is necessary in this situation. After surgery of the small bowel, subsequent chemotherapy could cause the wound dehiscence and perforation; therefore, adequate recovery time should be given before chemotherapy.

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Purpose: Malignant phyllodes tumors are rare breast tumors. Information on the prognosis and optimal treatment of these lesions is not yet sufficient. The aim of this study was to determine parameters that predict the recurrence of malignant phyllodes tumors of the breast. Methods: Retrospectively, we reviewed the medical records and pathological slides of 23 patients with malignant phyllodes tumors that had undergone surgical treatment from 1988 to 2006. The age of the patients, tumor size, type of surgery, resection margin, adjuvant therapy and pathological characteristics of the tumors such as stromal hypercellularity, cellular phleomorphism, mitosis, margins, and stromal pattern were examined. Results: The mean age of the patients was 41 yr. The tumor size ranged from 1 cm to 25 cm, with a median of 7.42 cm. The median follow-up time was 29.0 months. Recurrence was observed in 6 patients (26.1%) and the 5-yr disease free survival was 48.9%. Risk factors for recurrence of a malignant phyllodes tumor were a mitotic index greater than 10 per high-powered field (p=0.0242) and an invasive margin (p=0.0437). Conclusion: Frequent mitosis and an invasive margin were the principal determinants of recurrence. Patients with poor prognostic components should be treated more aggressively and the patients need more close follow-up.