Background: Histone deacetylase inhibitors are a new class of drugs used in treatment of malignant tumors. Diffuse large B-cell lymphoma (DLBCL) is the most common type of B-cell lymphoma, and it accounts for more than 40% of all B-cell lymphomas. In this study, we aimed to determine the expression patterns of histone deacetylases (HDACs) in DLBCL, to examine whether HDAC expression patterns differ among cases, and to assess whether these findings have clinical significance.

Nevus sebaceous (NS) is a common congenital hamartoma of the skin composed predominantly of sebaceous glands. Although most NS are benign skin tumors, malignant transformations have been reported. There is still controversy about the lifetime risk of malignant degeneration and precise surgical criteria. This study reports cases of malignant degeneration and suggests a surgical treatment algorithm. The medical records of patients with basal-cell carcinoma (BCC) arising from NS between January 2001 and January 2021 were retrospectively reviewed. Patient demographics including lesion location, and tumor size were investigated. The symptoms, histological findings before and after excision, complications, and recurrence during 2-year follow-up periods were investigated. Ten patients were identified with BCC arising from NS lesions. All patients were female and the mean age was 52.11 years. All patients complained of sudden morphological changes, the most common type being rapid color changes. Two cases had histological findings that showed a miss-match between punch biopsy and excisional biopsy results. No recurrence was detected 2 years after surgeries in any patients. Cases after third stage, especially in over 40 years who report morphologic changes, should undergo total surgical excision as the first approach, with strong suspicion of malignant degeneration.

Most diffuse gliomas are reported to harbor isocitrate dehydrogenase (IDH) mutations. However, when these mutations are tested in clinical practice, the results are often negative. This study examined the frequency of IDH1 and IDH2 mutations in gliomas classified according to the revised 2016 World Health Organization classification, and investigated their prognostic relevance. We tested 87 gliomas for IDH1 and IDH2 mutations using the peptide nucleic acid clamp method. IDH1 mutations were observed in 42% of diffuse astrocytomas, 23% of anaplastic astrocytomas, all oligodendrogliomas and anaplastic oligodendrogliomas, and 17% of glioblastomas. An IDH2 mutation was identified in one case of diffuse astrocytoma. In the survival analysis of diffuse astrocytic tumors, patients with IDH1/2-wildtype anaplastic astrocytomas tended to have a poor prognosis, similar to that of glioblastomas. IDH2 mutations were infrequent in gliomas. In anaplastic astrocytomas, the frequency of IDH1/2-wildtype was relatively high, and the prognosis of patients with this type of tumor was very similar to that of those with glioblastomas. It may therefore be necessary to reconsider the classification and treatment strategies for IDH1/2-wildtype anaplastic astrocytomas.

Chung YS, et al. J Korean Surg Soc. 2011 Aug;81(2):75-84. http://dx.doi.org/10.4174/jkss.2011.81.2.75

Calcifying fibrous tumor (CFT) is a recently recognized rare benign lesion characterized by dense hyalinized collagenous tissue with interspersed spindle cells and a lymphoplasmocytic infiltrate. Calcification is the hallmark of CFT and may present in the form of psammomatous bodies or dystrophic calcifications. CFT of the intestinal tract is uncommon and rectal CFT has never been reported. Recently, we experienced a case of CFT found in the rectum of a 36-year-old man. In this study, we described the characteristic histopathological findings with a review of the relevant literature. Although CFT of the intestinal tract as an intrinsic visceral lesion is unusual and clinically unexpected, CFT should be considered in the differential diagnosis of rectal submucosal tumor.

Background/Objectives: Malignant transformation of bone lesions, although rare, poses a major diagnostic and clinical challenge. Common benign lesions (e.g., osteochondroma, enchondroma, fibrous dysplasia, giant cell tumor), non-tumorous conditions (e.g., chronic osteomyelitis, irradiated bone, infarction), and low-grade malignancies (e.g., low-grade osteosarcoma, chondrosarcoma) can evolve into aggressive malignancies through distinct genetic, molecular, and microenvironmental pathways. Recognizing early malignant transformation on imaging is crucial for timely diagnosis and management. Methods: This review synthesizes current imaging characteristics, pathologic mechanisms, and clinical risk factors associated with malignant transformation of benign and low-grade malignancy bone lesions. Results: Atypical imaging findings and inaccurate biopsies can delay diagnosis. Aggressive features—such as cortical destruction, heterogeneous enhancement, and loss of internal matrix—should prompt further pathologic evaluation. Advanced imaging and a multidisciplinary approach with integrated clinicoradiologic–pathologic review are essential to minimize missed diagnoses. Patients with risk factors such as genetic syndromes, prior denosumab therapy, inadequate surgery, or prior radiation therapy require close monitoring or timely intervention. Conclusions: Radiologic–pathologic correlation remains central to distinguishing benign from malignant lesions. This review article emphasizes a comprehensive imaging-pathology overview of benign and low-grade malignancy bone lesions with malignant potential, aiming to improve diagnostic accuracy and outcomes in orthopedic oncology.