A large mass in the liver was incidentally observed on abdominal ultrasonography of a 75‒year‒old female during health surveillance. Computed tomography (CT) and magnetic resonance imaging revealed a tumor (φ>12 cm) in the medial segment of the liver. A liver biopsy was performed, and the tumor was histopathologically diagnosed as a neuroendocrine tumor (NET) G1. 18F‒fluorodeoxyglucose positron emission tomography‒CT (PET‒CT) and somatostatin receptor scintigraphy (SRS) revealed concomitant uptake in the hepatic tumor and no abnormal uptake in other organs; thus, the tumor was diagnosed as a primary hepatic NET (PHNET). Radical resection required right trisectionectomy of the liver, with little future remnant liver volume. The radical resection was performed 3 weeks post portal embolization. There were no surgical complications or obvious recurrence for 1 year post‒surgery. PHNETs are extremely rare and are difficult to diagnose using routine imaging modalities. PET‒CT and SRS are useful to exclude the presence of extrahepatic lesions and histopathological examination is required to diagnose PHNETs. Surgical resection is the first‒line treatment for PHNETs and even if the PHNET is large, a favorable prognosis can be achieved with radical resection.

We describe the cases of 4 patients with breast cancer who developed an allergy to fosnetupitant (Pro‒NETU). Case 1: A 67‒year‒old woman with breast cancer and bone metastasis received premedication that included Pro‒NETU. Minutes after administration, she complained of flushing, tachycardia, and dyspnea. Administration was discontinued. Minutes after discontinuation, the patient's symptoms were alleviated. She experienced no further complaints of such symptoms, and her premedication subsequently excluded Pro‒NETU. Case 2: A 50‒year‒old woman with early stage breast cancer received premedication that included Pro‒NETU. Minutes after administration, she complained of flushing, dyspnea, and drowsiness. Administration was discontinued. Minutes after discontinuation, her symptoms ameliorated. Case 3: A 41‒year‒old woman with early stage breast cancer received premedication that included Pro‒NETU. Minutes after administration, she complained of flushing, tachycardia, and dyspnea. Administration was thus discontinued, and she received an H2‒blocker and corticosteroid. Minutes after discontinuation, her symptoms were alleviated. Case 4: A 50‒year‒old woman with early stage breast cancer received premedication that included Pro‒NETU. Minutes after administration, she complained of flushing and tachycardia. Administration was discontinued. Minutes after discontinuation, her symptoms ameliorated. Fosaprepitant did not cause these allergies. The patients in cases 2, 3, and 4 had known allergies to docetaxel, and the cause of allergy in case 4 was unknown. Polysorbate 80, contained in docetaxel, fosaprepitant, and Pro‒NETU, was suspected to be the cause of allergy in cases 1, 2, and 3.

Epidermal growth factor receptor (EGFR) mutations are among the most common genetic alterations in non‒small cell lung cancer (NSCLC), with ex19del and ex21L858R being the most prevalent. Ex19del correlates with better outcomes of EGFR tyrosine kinase inhibitors (EGFR‒TKIs) than L858R. The RELAY phase Ⅲ study showed that ramucirumab plus erlotinib as first‒line therapy provided similar progression‒free survival for both mutations. Preclinical studies using NSCLC cell line PC9 (ex19del) and its CRISPR‒engineered subline PC9EX21 (ex21L858R mutations) were conducted to explore the molecular basis of these clinical observations and assess the impact of these mutations on cell biology and responses to EGFR‒TKI and ramucirumab. PC9 and PC9EX21 cells had similar morphology, but PC9EX21 cells were larger, grew slower, had greater migratory potential, and exhibited delayed tumor formation in vivo. Fluorescence‒activated cell sorting analysis showed lower EGFR and higher human epidermal growth factor receptor 2 (HER2)/HER3 expression in PC9EX21, with vascular endothelial growth factor receptor 2 mRNA levels 8‒times higher than ex19del. Transcriptomic profiling and multiplex proteomics identified significant gene expression differences (receptor tyrosine kinase) and altered signaling pathways in PC9EX21. Ramucirumab enhanced erlotinib's anti‒proliferative effect in PC9EX21 but had a limited effect in ex19del. These findings highlight key biological differences between ex19del and L858R mutations, emphasizing the need for personalized treatment strategies in NSCLC.

Tertiary lymphoid structures(TLS)are gaining attention as sites for anti‒tumor immune responses. They are observed in gynecological tumor tissues, including common gynecological cancers such as endometrial, cervical, and ovarian cancers. The distribution and maturity of TLS, along with molecular genetic factors and patient prognosis, are being studied. Enhancing anti‒cancer treatment is anticipated by efficiently inducing TLS within the tumor microenvironment. Specifically, based on basic research aimed at reactivating anti‒tumor immunity within TLS, numerous clinical trials are underway for novel combined therapies targeting TLS‒positive cancers. These trials involve optimal combinations of immune checkpoint inhibitors, immune‒activating molecules, chemotherapy, and radiotherapy to induce TLS. This has led to the development of new cancer treatment strategies.

Lung cancer remains one of the leading causes of cancer‒related mortality worldwide, underscoring the urgent need for innovative diagnostic and therapeutic approaches. The advent of immune checkpoint inhibitors(ICIs)has significantly transformed the treatment landscape, particularly for non‒small cell lung cancer(NSCLC). However, predictive biomarkers for ICI efficacy remain limited, with PD‒L1 expression, tumor mutational burden(TMB), and microsatellite instability providing only partial insight into therapeutic response. Recent attention has focused on tertiary lymphoid structures(TLS), ectopic lymphoid aggregates resembling secondary lymphoid organs that form in the tumor microenvironment. TLS are composed of B cells, T cells, dendritic cells, and other immune components, and play a central role in coordinating local antitumor immune responses. In NSCLC, the presence of TLS has been associated with favorable prognosis and improved response to ICIs, independent of PD‒L1 or TMB status. Moreover, emerging evidence suggests that the quality of TLS-such as the degree of maturation and the nature of infiltrating immune cells-may further influence immunotherapeutic outcomes. This review outlines the clinical significance of TLS in lung cancer, discussing their structure, function, and potential as novel biomarkers for stratifying patients undergoing immunotherapy. We also explore future directions including therapeutic strategies aimed at promoting TLS formation, such as vaccines or immune adjuvants, as well as the application of artificial intelligence and spatial omics technologies for the standardized evaluation and in‒depth characterization of TLS. As the integration of TLS analysis into clinical oncology evolves, a more precise and personalized approach to lung cancer immunotherapy may be realized.

Immune checkpoint inhibitors(ICI)have significantly improved treatment outcomes for advanced gastric cancer by enhancing anti‒tumor responses through increased activity of tumor‒infiltrating CD8+ T cells. This highlights the critical role of the immune microenvironment, drawing recent attention to tumor‒associated lymphoid structures(TLS). TLS, characterized by clusters of B cells, has been associated with favorable prognoses in various cancer types. Our research has demonstrated that TLS is present in gastric cancer tissue and correlates with improved survival outcomes and better responses to ICI treatment. Furthermore, we found that TLS promotes the infiltration of CD8+ T cells and the generation of tissue‒resident memory T cells. Advancing research on TLS holds promising potential for further improving treatment outcomes in the future.

The Ser/Thr-specific kinase, polo-like kinase 1 (Plk1), is a crucial eukaryotic cell cycle regulatory protein. Overexpression of this kinase is observed in many cancer cells and where it can be related to their aggressiveness. Dysfunction of Plk1 in cancer cells causes mitotic arrest and subsequent apoptosis. Accordingly, Plk1 is considered as a target for the development of anti-cancer agents. Plk1 has two domains, a catalytic kinase domain (KD) and a polo-box domain (PBD). PBD intramolecularly interacts with its KD and regulates Plk1 activity and localization. Therefore, in addition to the KD, the PBD is considered to be a potential drug target. We have been developing peptidic low-nanomolar-affinity PBD-binding inhibitors. However, these peptides do not show significant cytotoxicity, due to their low cell membrane permeability. To obtain cell-active Plk1 inhibitors, I applied a bivalent approach designed to simultaneously engage both KD and PBD regions of Plk1 for enhancing the potency, selectivity and lipophilicity. Here, I developed bivalent Plk1 inhibitors, in which the PBD-binding peptides are conjugated with the known KD-binding inhibitors BI2536 or wortmannin using PEG linkers. These bivalent inhibitors exhibit up to 100-fold enhanced Plk1 affinity relative to the best monovalent PBD-binding ligands, higher selectivity for tested kinases compared to BI2536, and significant cytotoxicity against HeLa cells.

The advent of novel anti-multiple myeloma (MM) agents has led to dramatic improvement in patient survival. Nevertheless, the majority of patients with MM have bone lesions, and destructive bone lesions significantly reduce quality of life. Progressive destructive bone lesions develop when osteoblast differentiation from bone marrow stromal cells is inhibited and osteoclasts are activated in the bone marrow microenvironment in patients with MM. Recent research has also shed light on the functions and roles of osteocytes, which account for the majority of bone cells. Since MM cells mainly invade the red marrow, bone lesions are often found in the skull, spine, and ilium, which contain red marrow. Imaging is essential for the diagnosis of MM bone lesions, and whole-body low-dose CT, whole-body MRI, and FDG-PET/CT have demonstrated utility. Furthermore, recent advances in anti-MM drugs have improved the prognosis of MM significantly, highlighting the importance of treating and managing MM bone lesions. This review will explain the molecular pathology and management of MM bone lesions.

We report a case of paratesticular rhabdomyosarcoma in a one-year and nine-months old male infant. The patient presented with an asymptomatic enlargement of the right scrotum. Ultrasonography indicated a solid mass 3 cm in size in the right scrotum. Computed tomography and magnetic resonance imaging revealed a right testicular tumor with no distant metastases. Serum lactate dehydrogenase, human chorionic gonadotrophin beta, and alpha-fetoprotein were within normal limits. Although surgical treatment was scheduled based on the diagnosis of the testicular tumor, the patient had a high fever with a viral infection, and the surgery was postponed. The tumor rapidly progressed to 7 cm in size within one month. High orchiectomy was performed, and histopathological examination confirmed a paratesticular rhabdomyosarcoma. The patient received adjuvant chemotherapy with vincristine sulfate, actinomycin D, and cyclophosphamide. There was no recurrence one year post-surgery. Paratesticular rhabdomyosarcoma commonly occurs in the paratesticular tissues of pediatric patients. This case highlights the importance of the differential diagnosis of paratesticular rhabdomyosarcoma other than testicular tumor for painless scrotal masses in infants and the requirement for multidisciplinary management in pediatrics.

The patient is an 80-year-old woman who initially underwent transurethral resection of a bladder tumor (TURBT) 7 years ago for bladder cancer at another hospital and was diagnosed with urothelial carcinoma (UC), high grade, pT1, followed by 8 cycles of intravesical BCG instillation therapy. Subsequently, her voiding urine cytology began to show suspicion of malignancy. When voiding urine cytology started to show positive findings, two transurethral biopsies of bladder mucosae and one selective upper tract urine cytology were performed with no evidence of malignancy, so she was followed up as an outpatient. She began experiencing spontaneous pain near the urethra and pain on urination 5 years after the initial TURBT. At this time, cystoscopy revealed redness on the posterior bladder wall. Additionally, redness of the vagina and induration of the labia were observed, raising suspicion of Paget's disease or Bowen's disease. She underwent a biopsy of the vulvar, which revealed UC. Ultimately, biopsies of the bladder, urethra, and vulvovaginal regions were performed at our hospital to determine a treatment plan. Immunohistochemical staining of the vulva was positive for cytokeratins 7 and 20 and negative for GCDFP15, confirming a diagnosis of extramammary Paget disease secondary to bladder CIS. As a result, the patient underwent radical surgery, including removal of the vagina, uterus, bladder, and labia. Pathological findings showed extensive CIS in the vagina and labia majora. Herein, we report a very rare case of secondary extramammary Paget disease extending from bladder CIS to the vagina and labia.

A 62-year-old female was referred to our hospital for further evaluation of a right renal mass. Contrastenhanced computed tomography (CT) revealed a 36 mm solid mass in the middle portion of the right kidney with early enhancement and washout, leading to a preoperative diagnosis of right renal cell carcinoma (cT1aN0M0, stage I). The patient underwent robot-assisted partial nephrectomy (RAPN). Histopathological examination showed spindle-cell proliferation arranged concentrically around the blood vessels, and immunohistochemical staining was positive for calponin and α-SMA, confirming the diagnosis of myopericytoma. No recurrence or metastasis was observed during the six months of follow-up.

A 46-year-old woman presented to a local clinic complaining of discomfort in the right upper quadrant. Abdominal ultrasound revealed a right renal mass, and she was referred for further evaluation and treatment. Contrast-enhanced computed tomography showed a 54 mm right renal tumor and a 12 mm enlarged lymph node in the aortocaval region. She was diagnosed with right renal cell carcinoma, staged as cT1bN1M0. Laparoscopic right nephrectomy and lymph node dissection were performed, confirming the diagnosis of papillary renal cell carcinoma type 2, pT1bpN1. At nine months after surgery, she developed retroperitoneal recurrence with invasion of the second lumbar vertebra. Pembrolizumab combined with axitinib was initiated. After six months of treatment, she achieved a complete response with no detectable lesions. However, 17 months after the initiation of treatment, new multiple liver metastases appeared, and the response was classified as progressive disease. Second-line treatment with cabozantinib was started, leading to complete tumor regression after 16 months, with a complete response confirmed. She has maintained a complete response for 39 months since starting cabozantinib.

A woman in her 70s. In May, a pancreatic tumor was detected during a medical checkup, and she visited the Department of Gastroenterology of our hospital. She had no subjective symptoms, but she was diagnosed with primary pancreatic cancer and multiple bone metastases. She was undergoing outpatient chemotherapy. In November of the same year, she became aware of numbness in the right cheek area and was referred to our department. Neurologically, abnormal sensation in the area of the second branch of the right trigeminal nerve was observed. Head computed tomography (CT)/MRI showed a mass lesion in the right Meckel's cave, and FDG-PET showed multiple bone lesions as well as abnormal accumulation in the right Meckel's cave. Based on the above, we diagnosed the patient with numb cheek syndrome due to metastasis of pancreatic cancer to Meckel's cave. Neurologists should be aware that numb cheek syndrome can occur in association with an underlying malignancy.

A 73-year-old man was referred to our hospital for abnormal shadow. Chest computed tomography (CT) showed a tumor with a cavity in S10 of the left lung. Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed the accumulation in the tumorous lesion of the cavity wall. Although the culture of the lavage fluid was positive for acid-fast bacilli and polymerase chain reaction (PCR) was positive for M. intracellulare, coexistence of cancer could not be denied. Therefore, he underwent surgery. Histopathological findings showed squamous cell carcinoma adjacent to epithelioid cell granulomatous lesion of nontuberculous mycobacteriosis.

A woman in her 30s with a left posterior mediastinal tumor incidentally found on a chest computed tomography (CT) was referred to our hospital. Chest CT revealed a dumbbell-shaped tumor of 37 mm in diameter located on the paravertebral region at the left Th9/10 level. The tumor extended into the Th9 intervertebral foramen, but did not extend into the spinal canal. Three dimensional (3D)-CT showed the artery of Adamkiewicz (AKA) with a hair-pin turn from the 11th left intercostal artery. We performed surgical treatment. First, the nerve root was dissected by the posterior approach. Next, the tumor was resected by thoracoscopic surgery. The postoperative pathological diagnosis was neurinoma. In surgical resection of posterior mediastinal tumors (especially on the left side) located between the eighth thoracic vertebra and the first lumbar vertebra, it is considered important to identify AKA preoperatively in order to prevent postoperative paraplegia.

Teratomas are broadly classified according to the presence or absence of germ cell neoplasia in situ (GCNIS), which is defined as neoplastic germ cell proliferation in the seminiferous tubules. Postpubertaltype teratoma is classified into a germ cell tumor derived from GCNIS, and it is malignant in adults. However, a prepubertal teratoma is classified as a germ cell tumor unrelated to GCNIS. It is common in children and has a benign course. We report a case in a 60-year-old man who had been aware of a nodule in his left scrotum for 15 years, and felt heaviness and pain from a few months before he visited a specialist. He visited a local urologist and was referred to our department under the diagnosis of a left testicular tumor in February 202X. In March 202X, he underwent a left high orchiectomy. A 12×5 mm white mass lesion was observed, and a pathological examination showed intestinal epithelial and bronchial epithelial structures. Additionally, no GCNIS was found in background seminiferous tubules. There was no amplification of chromosome 12 short arm as shown by the fluorescence in situ hybridization method. On the basis of these pathological findings, prepubertal-type teratoma was diagnosed in this patient.

An 81-year-old man presented to our hospital with left lower back pain. The computed tomographic scan revealed a retroperitoneal tumor with a heterogeneous contrast effect. Magnetic resonance imaging scan showed that the tumor was suspected to have invaded the left diaphragm, iliopsoas muscle, and pancreas, and an unclear boundary between the tumor and left kidney. Based on these findings, a left retroperitoneal sarcoma or renal carcinoma was suspected. A left retroperitoneal tumor resection, combined with left nephrectomy, was performed. A thoracoabdominal approach was chosen due to suspected diaphragmatic invasion and the need for an adequate operative field on the cephalic side of the kidney. The tumor was resected along with the left kidney, a portion of the diaphragm, and a portion of the iliopsoas muscle, without pancreatic resection. Pathological examination confirmed a dedifferentiated liposarcoma. No intraoperative or postoperative complications were encountered. Surgical resection with a negative surgical margin is crucial for the treatment of retroperitoneal liposarcoma. The thoracoabdominal approach provides excellent surgical exposure and allows for early vascular control. Although the thoracoabdominal approach is rarely used in urological surgery due to concern about the morbidity associated with violating the thoracic cavity, it can be performed effectively and safely for large or invasive retroperitoneal tumors in select cases requiring maximal surgical resection.

We report a rare case of a solitary metastasis in which long-term complete remission was achieved with chemotherapy alone. An 81-year-old woman underwent a right hemicolectomy and D3 lymph node dissection for ascending colon cancer. Pathological findings showed type 2, 40×20 mm, tub2>muc, pT3, int, INF b, ly1, v0, pN1(1/32), pPM0, pDM0, and fStage Ⅲa. However, the patient chose not to undergo adjuvant chemotherapy and opted for further observation. Five months after the surgery, lymph node metastasis was observed near the right external iliac artery. Because the patient did not wish to undergo surgical treatment, SOX therapy was initiated. Owing to considerable side effects, the patient's treatment was switched to oral S-1. Gradually, the lesion disappeared, and the treatment was changed to UFT. The patient has maintained complete long-term remission for 10 years postoperatively. Here, we report this case along with a literature review.

While recent advances in chemotherapy for pancreatic cancer have improved treatment outcomes, pathological complete responses(pCR)remain rare. Here, we present four cases of pancreatic cancer in which a pCR was achieved following chemotherapy. Three cases were classified as borderline resectable and one was resectable. Two patients received gemcitabine+nab-paclitaxel, 1 received mFOLFIRINOX, and one received gemcitabine+S-1 therapy. Histopathological examination after resection revealed only fibrosis and scarring. No tumor cells were found in any of these cases, leading to diagnoses of pCR. Two of the 4 patients survived without recurrence for a long time. The other 2 patients experienced recurrence, one of whom died 8 months after surgery.

The patient was a 79-year-old male diagnosed with gastric cancer with lung metastasis(cT3N2M1[PUL], cStage ⅣB)and sigmoid colon cancer(cT3N0M0, cStage Ⅱa). He underwent systemic chemotherapy with the SOX plus nivolumab regimen for unresectable advanced gastric cancer. Six months after the initiation of chemotherapy(9 courses), the primary tumor and lymph node metastases in the lesser curvature and suprapancreatic margin had shrunk, and the lung metastases had disappeared. However, chemotherapy was discontinued because of the development of immune-related interstitial pneumonia, and steroid therapy was initiated. Nine months after the initiation of chemotherapy, the tumor shrinkage rate remained constant and interstitial pneumonia improved; however, the patient was referred to our hospital for surgical treatment for gastric stenosis. A laparoscopic distal gastrectomy was performed for gastric cancer. Histopathological findings revealed no residual cancer cells in the primary tumor or lymph nodes, and the histological response was Grade 3. The patient remained recurrence-free for 10 months after the surgery. SOX plus nivolumab therapy for unresectable advanced gastric cancer is expected to have a high tumor-shrinkage effect, and combining it with conversion surgery may lead to an improved long-term prognosis.