Cells experiencing significant stress such as irreparable genomic damage enter a state called cellular senescence, where their cell cycle is irreversibly arrested. Originally, cellular senescence was thought to serve as a crucial mechanism for suppressing carcinogenesis by stopping the growth of abnormal cells that could potentially lead to cancer development. However, it has become evident that senescence induced by treatments such as chemotherapy can contribute to drug resistance in cancer by exhibiting resistance to cell death and allowing cancer cells to survive. Furthermore, senescent cells exhibit a property known as the senescence-associated secretory phenotype(SASP), where they release a variety of inflammatory molecules and growth factors. Through these SASP factors influencing the tumor microenvironment, senescent cells can be deeply involved in various cancer pathologies such as carcinogenesis and the acquisition of drug resistance. This article provides an overview of the multifaceted and complex interplay between cellular senescence and the initiation and progression of cancer.

Undifferentiated sarcoma of the liver is rare, especially in adults, and is an aggressive malignancy that originates from the primary mesenchymal tissues. A 53-year-old man was referred to our hospital for further evaluation of a low-grade fever. Contrast-enhanced CT revealed an 18-cm tumor in the right lobe of the liver. The tumor was characterized by low-density areas suspected of cystic components, a high-density area suspected of hemorrhage, and contrast enhancement in the thickened marginal and internal septa. MRI revealed a high-intensity tumor with a heterogeneous structure on T2-weighted images. Angiosarcoma of the liver with intratumoral hemorrhage was suspected, and right hepatectomy was performed. The pathological diagnosis was an undifferentiated sarcoma based on the presence of undifferentiated mesenchymal tumor cells with a stellate to spindle-shaped pleomorphism. Following a multidisciplinary discussion, 4 courses of the AI regimen (doxorubicin and ifosfamide)were administered as adjuvant chemotherapy, and no recurrence was confirmed at 2 years and 6 months follow-up. Our case suggests that radical resection followed by adjuvant chemotherapy may contribute to a favorable prognosis for undifferentiated sarcoma of the liver.

A 64-year-old man complained of lower abdominal pain and vomiting. The CT scan showed adhesional ileus; therefore, small bowel resection procedure was performed. Histological findings showed signet-ring cell carcinoma and poorly differentiated adenocarcinoma. We performed ileocecal resection as an additional surgery. The operative findings revealed peritoneal nodules. The histological findings suggested goblet cell carcinoid with peritoneal dissemination. mFOLFOX+bevacizumab was administered, and no progression was observed for 30 months after the surgery. Appendiceal goblet cell carcinoid is rare and its prognosis is poor. Here, we report a case of appendiceal GCC that achieved a relatively long-term survival despite peritoneal dissemination.

Adenomyoepithelioma(AME)of the breast is a rare condition, and comorbidity with carcinoma is even more unusual. Herein, we report a case of both AME and apocrine carcinoma in different breasts of a single patient. A 48-year-old woman presented to our clinic with a right breast tumor. Fine needle aspiration cytology(FNAC)was indeterminate and suspicious for both papilloma and non-invasive ductal carcinoma, but excisional biopsy indicated an AME. Immuno-histochemical staining showed EMA(+), AE1/3(+), and CK7(+)mammary duct cells and αSMA(+), CK5/6(+), and p63(+) myoepithelial cells. Six months later, the patient noticed a left breast tumor, and although FNAC indicated no malignancy, after 6 additional months, the tumor size had increased and a mammography revealed tumor microcalcification, suggesting malignancy. Vacuum-assisted biopsy revealed an apocrine carcinoma. The patient underwent partial mastectomy and sentinel node biopsy, followed by radiotherapy and chemotherapy. The post-surgical pathology was pT1pN0M0, Stage Ⅰ, triple- negative, and the patient was disease-free for 12 years postoperatively. To our knowledge, this is only the second case of AME and breast cancer in different breasts reported in Japan.

Pseudocirrhosis, which is radiologically and clinically similar to liver cirrhosis, may develop following chemotherapy for breast cancer with liver metastasis. There are few reports of eribulin treatment. We report 5 patients with metastatic or recurrent breast cancer who developed pseudocirrhosis during eribulin treatment. All patients had diffuse liver metastasis, and the liver metastases significantly reduced in size during the early phase of eribulin treatment, when they developed pseudocirrhosis. Subsequently, the patients had poor prognoses.

Serum KL-6 is elevated in patients with various diseases such as interstitial lung disease(ILD), lung cancer, or breast cancer. However, whether serum KL-6 levels would be increased in patients with gastric cancer remains unclear. In this study, we aimed to reveal the frequency and characteristics of patients with gastric cancer exhibiting high serum KL-6 levels and no ILD. Therefore, we retrospectively reviewed the medical records of patients with gastric cancer and serum KL-6 levels measured prior to nivolumab-containing therapies. No patients had ILD at pretreatment. The median serum KL-6 level at pretreatment was 314 U/mL. Serum KL-6 levels increased above 500 U/mL in 16 of 56 patients at pretreatment. Serum KL-6 levels were higher in smokers and ex-smokers than in never-smokers as well as in patients with multiple metastases than in those with a single metastatic lesion. Moreover, we conducted a representative case presentation. Due to the increasing immune checkpoint inhibitor use in gastric cancer management, awareness concerning potentially increased serum KL-6 levels in patients with gastric cancer without ILD would be useful for physicians due to the more frequent opportunities to measure serum KL-6 levels for early detection and differential diagnosis of ILD.

After endoscopic treatment for esophageal cancer, a 65-year-old male underwent surveillance esophagogastroduodenoscopy. A 12-mm discolored flat lesion was noted on the greater curvature of the middle gastric body. Magnifying endoscopy with blue laser imaging demonstrated an irregular papillary surface. Biopsy revealed atypical cells with mucus and irregularly distributed nuclei. The lesion was diagnosed as a gastric-type neoplasm with low atypia. Thereafter, endoscopic submucosal dissection (ESD) was conducted and specimen was sent for biopsy. The ESD specimen suggested a signet-ring cell carcinoma with MUC5AC-positive phenotype and adenocarcinoma of the fundic gland type, with MUC6 positivity and pepsinogen I positivity in the shallow and deeper layers, respectively. Moreover, the cervical region of fundic glands demonstrated a transformation zone of the signet-ring cell carcinoma into an adenocarcinoma of the fundic gland type. Herein, we report this rare case along with a literature review.

Herein, we aimed to examine the diagnostic yield and utility of boring biopsy for subepithelial lesions (SEL) of the stomach and esophagus. A total of 52 patients with SELs of the stomach or esophagus underwent boring biopsy. The diagnostic yield of boring biopsy for gastric and esophageal SELs was 50% (21/42) and 80% (8/10), and for SELs with a diameter of less than 10mm, the diagnostic yield was 67% (6/9) and 83% (5/6), respectively. Forty-three percent (9/21) of the gastric SELs were diagnosed with gastrointestinal stromal tumor (GIST), while all esophageal SELs (8/8) were leiomyomas. Ten percent (4/42) of boring biopsies for the stomach were accompanied by complications:two cases of perforation and two of bleeding.

Myelodysplastic syndrome (MDS) is a refractory cancer that arises from hematopoietic stem cells and predominantly affects elderly adults. In addition to driver gene mutations, which are also found in clonal hematopoiesis in healthy elderly people, systemic inflammation caused by infection or collagen disease has long been known as an extracellular factor in the pathogenesis of MDS. Wild-type HSCs have an "innate immune memory" that functions in response to infection and inflammatory stress, and my colleagues and I used an infection stress model to demonstrate that the innate immune response by the TLR-TRIF-PLK-ELF1 pathway is similarly critical in impairment of hematopoiesis and dysregulation of chromatin in MDS stem cells. This revealed that not only are MDS stem cells expanded by the TRAF6-NF-kB pathway, the innate immune response is also involved in generating MDS stem cells. In this review, I will present research findings related to "innate immune memory," one of the pathogenic mechanisms of blood cancer, and discuss future directions for basic pathological research and potential therapeutic development.

T cell malignancies pose several unique issues for CAR-T cell therapy that were not significant concerns with CAR-T cells for B-cell malignancies. A general problem to consider in the production of CAR-T cells is "on target-off tumor toxicity." This occurs when the antigen targeted by the CAR-T cells is also expressed on normal cells, not just tumor cells, which causes CAR-T cells to damage these normal cells. In CAR-T cell therapy for T cell tumors, antigens expressed on T cells (such as CD5, CD7, etc.) are the targets, which leads to a problem known as "fratricide," where CAR-T cells kill each other. Other issues include T cell aplasia and contamination of CAR-T cell products with tumor cells. However, several recent clinical trials have shown excellent outcomes for CAR-T cell therapy when genome editing technology is used to overcome these issues by knocking out target antigens or T cell receptors. This review article outlines these challenges and their solutions and discusses the results of recent clinical trials.

A 65-years-old man undergoing hemodialysis for chronic kidney disease was diagnosed with ascending colon cancer and 3 hepatic metastases. He was administered mFOLFOX6 (reducing the dose to 50%) plus bevacizumab (BEV) therapy. Hemodialysis was performed 4 h after administration of oxaliplatin on day1 and repeated three times a week. No serious adverse events were observed. After 4 courses of chemotherapy, a computer tomography scan showed that the hepatic metastases had reduced. 2 courses of mFOLFOX6 (increasing the dose to 75%) plus BEV therapy were added, he was operated by laparoscopic right hemicolectomy and laparoscopic patrial hepatectomy. He has been in remission for 2 years and 4 months since the surgery. Dose-adjusted chemotherapy with hemodialysis was effective and improve the prognosis of the patient.

The need for resection of the meningioma capsule has long been debated and remains controversial. Even the definition of a capsule does not seem to have been established. We described the histopathological findings of the so-called capsule and the necessity for resection, considering tumor cell invasion and recurrence, based on a literature review.

In contrast to other cancer research areas, the development of chemotherapy and radiotherapy for meningiomas has been challenging, lacking standardized criteria for assessing treatment response and progression. Although efforts by RANO have proposed evaluation criteria, a consensus on effective evaluation parameters for meningiomas remains elusive. This paper underscores the importance of establishing efficacy endpoints in clinical trials, compares efficacy assessment in meningioma research with other solid tumor areas, and outlines the challenges ahead in meningioma research. Recent analyses revealed the absence of consensus on efficacy endpoints in meningioma trials, complicating trial design and hindering cross-trial comparisons. The unique anatomical constraints and histological variability of meningiomas pose challenges in determining appropriate efficacy measures. To address these challenges, future research must focus on accumulating prognostic data, standardizing evaluation criteria, and considering multiple endpoints in trial designs. Akin to other cancer areas, investigating targeted therapies and establishing international consensus on efficacy endpoints are crucial steps forward.

Most meningiomas are benign, slow growing tumors, which rarely progress to a higher grade. The incidence rate of malignant progression is estimated to be 2.98/1000 patient-year. However, non-skull base location is a significant risk factor for progression. The median time to malignant progression is 4.3 years; however, the cumulative rate of progression approaches a plateau after 10 years. Although radiosurgery does not appear to increase the incidence rate(0.5/1000 patient-year), exact comparisons have been difficult because of differences in study populations. The median time to progression is 7.0 years from initial diagnosis and 5.0 years from radiosurgery. The cumulative rate appears to increase even after 10 years. The risk of malignant transformation after radiotherapy may increase in patients with tumor-prone syndromes, with some controversies regarding patients with neurofibromatosis type 2. Although short term follow-up in patients with meningioma suggests that radiosurgery is safe, there is uncertainty regarding its use in pediatric patients, and those with tumor-prone syndromes.

The jugular foramen, also known as the foramen magnum, is a highly intricate region of the skull base through which numerous critical blood vessels and nerves traverse. Meningiomas, the most common tumors in neurosurgical pathology, can arise at any location where the meninges are present, posing significant challenges. Meningiomas involving the jugular foramen and sublingual neural tube are particularly notable for their potential to extend from intracranial to extracranial sites, necessitating familiarity with extracranial anatomy, which is not typically encountered in clinical practice. A comprehensive understanding of anatomical characteristics, along with an ample field of view and working space, is crucial for handling the cerebellum, brainstem, and nerves meticulously. The use of surgical support tools such as neuromonitoring and navigation is essential for enhancing the safety of the procedure. Furthermore, preparedness for treatment options, rehabilitation, and adjunctive therapies is vital in the event of neurological symptoms such as those affecting the glossopharyngeal, vagal, or hypoglossal nerves.

During surgery for meningioma, basic surgical techniques and strategies required for the removal of the tumor are common, particularly for tumors located superficially, such as convexity, parasagittal, and falx meningiomas. Four basic surgical techniques, including detachment; devascularization; debulking; and dissection should be combined and repeated in appropriate sequence, tailored to the specific conditions of each tumor. This eventually enables the total circumferential dissection of the tumor from the surrounding tissues. It is essential to retract the tumor towards the space created at the tumor center through internal debulking, rather than retracting the normal brain, to avoid damage to the surrounding brain tissue. During surgery for parasagittal meningioma with venous sinus occlusion, it is crucial to preserve the cortical veins that have developed as collateral pathways to prevent venous complications. During surgery for falx meningioma, the selection of a surgical approach including a contralateral approach based on factors such as the development of bridging veins and significant peritumoral brain edema is required. In this article, detailed surgical procedures for convexity meningioma, parasagittal meningioma, and falx meningioma were described focusing on the application of fundamental surgical techniques tailored to each tumor type.

Meningiomas are the most common brain tumors, often in the form of extra-axial masses adhering to the dura mater. Although there are typical imaging findings, meningiomas have a wide variety of imaging findings, owing to their different histological subtypes. Thus, it can be difficult to differentiate meningiomas from other diseases that present with similar imaging findings. This section outlines mimickers for monitoring meningiomas that present with imaging findings similar to those of meningiomas. Diseases that form masses and require differentiation from meningiomas include schwannomas, solitary fibrous tumors, dural metastases, and histiocytosis. Diseases that primarily present as dural thickening and require differentiation from meningiomas include hypertrophic duralitis, fungal infections, and IG4-related diseases. Notably, in addition to the various pathologies that can mimic meningiomas, such as those listed above, there are also cases in which the diagnosis of meningioma is difficult because of additional modifications, such as metastasis or meningioma infarction.

The frequency of identification of asymptomatic meningiomas is increasing owing to the advancement and widespread use of CT and MRI. The first choice for asymptomatic meningiomas is observation. Approximately 70% of asymptomatic meningiomas increase in volume on long term follow-up. More than half of them reportedly exhibit a self-limiting pattern, in which growth eventually stops. Imaging findings related to increased meningioma volume include no calcification, large tumor size, high signal intensity inside the tumor on T2-weighted images, high brightness within the tumor on diffusion-weighted images, and perifocal edema. We also highlighted the presence of hypo-intensity of the surface layer on T2-weighted imaging, indicating growth arrest in a self-limiting growth pattern of meningioma. In this article, literature reports on image prediction using CT and MRI regarding the growth of asymptomatic meningiomas were reviewed, along with our report.

Meningiomas are the most common primary intracranial tumors. As the number of incidentally discovered meningiomas has increased with the widespread access and use of neuroimaging, treatment strategies for meningiomas have become more important. Close observation is the first choice for asymptomatic lesions; however, the natural history of meningiomas remains unclear. It is necessary to recognize the characteristics of meningiomas that are likely to grow, such as high signal intensity on MRI T2WI. It is also important to examine the growth rates and patterns using multiple neuroimaging examinations during the follow-up period. The authors suggested a relationship between the various observed growth patterns and the length of the follow-up period based on the assumed development of tumor volume. Less than 10% of patients with asymptomatic meningiomas develop symptoms and require treatment. However, it remains unclear which lesions become symptomatic, and further studies are required. Lesions with a sustained growth pattern undergo preventive treatment interventions, but the need for and appropriate timing of these interventions are continuously under debate. Further studies will help elucidate the natural history of meningiomas.

Meningiomas, renowned for their histological diversity, are one of the most prevalent brain tumors. Some meningiomas show unusual histomorphology, especially in intraoperative rapid diagnosis. Therefore, clinical and radiological information is crucial for pathological diagnosis. Before the 2021 World Health Organization Classification of Tumors of the Central Nervous System(5th edition), pathological diagnosis relied solely on histopathological features. However, this classification introduced new diagnostic criteria for anaplastic meningiomas, which now include TERT promoter mutations and the homozygous deletion of CDKN2A/B, indicating the necessity of genetic analysis. Some rhabdoid and papillary meningiomas have BAP1 alterations, which tend to demonstrate an aggressive clinical course and may represent a phenotype of BAP1-related tumor predisposition syndrome. Heterozygous deletion of CDKN2A/B and loss of H3 p.K28me3(K27me3)are also associated with poor prognosis. Although some immunohistochemical markers like MTAP may serve as surrogates for the homozygous deletion of CKKN2A/B, genetic analysis is required to confirm TERT promoter mutations. Therefore, in routine clinical practice, neurosurgeons and pathologists prioritize appropriate formalin fixation to facilitate genetic analysis using pathological specimens.