A 78-year-old male patient came to our hospital with a chief complaint of fever. Computed tomography revealed an indistinct tumor in the pancreatic head, along with dilatation of the bile duct and main pancreatic duct. An endoscopic transpapillary biopsy demonstrated adenocarcinoma in the glandular epithelium and a dense formation of quasi-round cells. Pathology results indicated positive CK AE1/AE3 and INSM-1, negative CD45, and a Ki67 index of about 80%, leading to a diagnosis of neuroendocrine carcinoma (NEC) Grade 3 of the pancreatic head. Consequently, a pancreatoduodenectomy was performed. Postoperative pathology revealed small cell NEC (SCNEC) at the pancreatic head, with infiltrative growth of atypical gland ducts around the bile ducts, indicating the presence of a well-differentiated adenocarcinoma. The adenocarcinoma contained in situ lesions and biliary intraepithelial neoplasia (BilIN), with SCNEC being contiguous. Therefore, the diagnosis was NEC originating from the extrahepatic bile duct, which invaded the pancreatic head. NEC of the extrahepatic bile duct is rare, accounting for approximately 0.2-2% of gastrointestinal neuroendocrine tumors, and it has a poor prognosis, similar to other gastrointestinal NECs, even when surgical treatment is performed. The patient remained an outpatient without recurrence 17 months postoperatively.

Primary hepatic lymphoma (PHL) is a lymphoproliferative disorder confined to the liver, with no evidence of lymphomatous involvement in other organs. Here, we report a case of diffuse large B-cell lymphoma (DLBCL)-type PHL in a patient with a long history of primary biliary cholangitis (PBC) and Sjögren's syndrome (SS). A 78-year-old woman presented with epigastralgia and was found to have a solitary liver tumor by contrast-enhanced computed tomography (CT). A CT scan performed 8 months earlier was unremarkable, with no extrahepatic lesions observed. The patient underwent laparoscopic left lateral segmentectomy, and the resected specimen showed histological features of DLBCL in the background of PBC-affected liver parenchyma. The patient received postoperative R-CHOP chemotherapy and has remained in complete remission for 4 years. PBC-associated PHL is extremely rare, and five of six reported cases of PBC-associated PHL cases showed a histological subtype of MALT lymphoma. In this case, immune dysregulation caused by PBC and secondary SS may have contributed to the development of DLBCL-type PHL.

Spontaneous rupture of renal cell carcinoma (RCC) occurs in 0.3-0.6% of all RCC cases. A 57-yearold woman presented to the emergency department with a chief complaint of hematuria and lower back pein. Ruptures of a kidney tumor and a kidney capsular hematoma were detected using computed tomography. The patient underwent radical right nephrectomy 22 days post admission, and the pathological diagnosis was chromophobe RCC (ChRCC). To our knowledge, this is the third reported case of ChRCC. The previous two cases did not exhibit postoperative recurrence, and yielded good prognoses. However, in our case, liver metastasis occurred 1 month postoperatively, and the prognosis was poor.

The patient was a 21-year-old man with a shadow on a chest roentgenogram taken during a medical checkup. According to blood testing, thoracoabdominal computed tomography, head magnetic resonance imaging, and lung tumor biopsy, we diagnosed a primary retroperitoneal germ cell tumor with multiple lung and brain metastases. Induction chemotherapy (4 courses of Bleomycin, Etoposide and Cisplatin) was started immediately. Because tumor markers remained elevated, salvage chemotherapy (4 courses of paclitaxel, ifosfamide cisplatin) was administered. Since the tumor markers remained elevated third-line chemotherapy was considered. However, because the tumor markers continued to decrease gradually and the tumor continued to shrink on imaging, expectant management was given. Three months later, the tumor markers turned negative, and retroperitoneal lymph node dissection and resection of lung metastases were performed. No cancer cells were found in any of the tissue samples. Careful monitoring after completion of chemotherapy may spare unnecessary chemotherapy.

We examined the efficacy and adverse effects of low-dose intravesical Bacillus Calmette-Guérin (BCG) therapy in patients with non-muscle-invasive bladder cancer. Patients who underwent intravesical BCG therapy (n＝176 ; 198 courses) at our hospital between April 2012 and December 2022 were enrolled. After assigning patients to either the low-dose or regular-dose (40 or 80 mg of BCG Tokyo 172 strain) groups, treatment efficacy and incidence of adverse events were compared. The mean number of BCG infusions in the low-dose and regular-dose groups was 6. 8 and 7. 8,respectively,although the difference was not statistically significant (P＝0.28). The median number of BCG infusions in both groups was eight, with no significant difference between them (P＝0.28). The median follow-up period after BCG therapy was 32 and 37 months in the low-dose and regular-dose groups, respectively. There were no significant differences in recurrence-free or cancer-specific survival between the groups. Although the incidence of adverse events in the low-dose group was lower than that in the regular-dose group, there was no significant differences between the groups. Multivariate analysis showed that fever and reactive arthritis were independent predictors of discontinuation of BCG therapy. Therefore, low-dose BCG therapy may be an effective treatment option for non-muscle-invasive bladder cancer.

An 80-year-old woman with epigastric pain and weight loss presented to our hospital with cancer of the ascending colon and cholelithiasis. Initially hospitalized for a suspected gallstone attack, she later developed gangrenous cholecystitis. She underwent a laparoscopic cholecystectomy, which revealed abscess formation and necrosis extending into the gallbladder duct. The patient was discharged on the 10th postoperative day but was readmitted for a laparoscopic right hemicolectomy. During this surgery, extensive adhesions were encountered, which prolonged the procedure; however, it was completed with a D3 dissection. She had a successful postoperative recovery and was discharged on the 9th postoperative day. The incidence of gallstones in patients with colorectal cancer is high, and acute cholecystitis can occur. In this case, we performed a two-stage surgery and achieved a radical cure without any postoperative complications. Two-stage surgery may be an option for patients with severe symptoms and inflammation associated with acute cholecystitis.

An 87-year-old man with complaints of palpitations and digestive bleeding previously visited another hospital. He was referred to our hospital because of anemia. Small bowel endoscopy revealed an elevated lesion with bleeding from the ileum. Partial resection of the small intestine was performed, and small intestinal angiosarcoma was diagnosed. The patient was referred to another hospital upon his request. Radiotherapy was performed for tertiary chest metastases. Nine months after the surgery, the patient visited our hospital with hematochezia. Surgery was performed because of suspected recurrence at the anastomotic site. Histopathological examination confirmed the recurrence of angiosarcoma of the small intestine. The patient is currently undergoing outpatient observation. Angiosarcoma has a poor prognosis, although it is important to select the appropriate treatment according to the patient's age and general condition.

A 70-year-old man was admitted to a local hospital with epigastric pain and diagnosed with type-2 gastric cancer. Contrast-enhanced CT scan showed metastases in S3 and S8 of the liver, and the tumor was classified as type cT4aN2H1, cStage ⅣB. Nivolumab monotherapy was initiated after failure of treatment with S-1 plus oxaliplatin and ramucirumab. After 6 courses, the primary tumor, lymph nodes, and liver metastases had shrunk to a remarkable degree. The patient underwent a proximal gastrectomy with D2 lymph node dissection and partial liver resection. Histopathological examination revealed no remaining tumor cells, with a histological response Grade 3.

A 62-year-old man was diagnosed with Stage Ⅲ signet ring cell carcinoma of the lower thoracic esophagus. The patient underwent 2 courses of neoadjuvant cisplatin and 5-fluorouracil(SP therapy), demonstrating stable efficacy. Subsequently, the patient underwent subtotal esophagectomy with thoracoabdominal 2-field lymphadenectomy via right thoracotomy, followed by esophageal reconstruction using a gastric tube through a retrosternal route. Pathological examination revealed a signet ring cell carcinoma of the esophagogastric junction(pT3, pN2, sM0, and fStage Ⅲ). Postoperatively, the patient received chemotherapy with S-1 for 2 years owing to multiple lymph node metastases. Remarkably, the patient remained free of recurrence 6 years after surgery. We encountered a case of long-term survival in esophagogastric junction cancer with multiple lymph node metastases, typically associated with poor prognosis, following pre- and postoperative chemotherapy and radical surgery.

A 71-year-old woman visited our hospital with pain and itching in her left breast which had commenced the day before admission. On palpation, we detected a 2.0 cm nodule, indicative of an elastic and hard tumor located centrally in the left breast. Mammography revealed an oval, microlobulated mass in the central quadrant of the left breast. Ultrasonography indicated a 1.5×1.3 cm hypoechoic lesion at the 12 o'clock position near the left nipple. Core needle biopsy revealed an invasive ductal carcinoma. Therefore, we mastectomized the left breast. Histologically, the tumor mass exhibited total necrosis, with viable carcinoma cells detected in a paramammary lymph node at the resected breast edge. Consequently, the tumor was diagnosed as a solid tubular carcinoma with total infarction and necrosis. Here, we present a rare case of breast cancer associated with infarction and necrosis.

In this study, we report the case of a patient with triple-negative breast cancer who achieved a pathological complete response(pCR)following neoadjuvant chemotherapy but experienced early recurrence and had a poor prognosis. A 46-year-old woman with a diagnosis of triple-negative breast cancer(cT2cN3cM0, cStage ⅢC)received neoadjuvant chemotherapy with dose-dense doxorubicin and cyclophosphamide, followed by weekly paclitaxel. The patient underwent a mastectomy and axillary lymph node dissection, achieving pCR. Subsequently, she received postmastectomy radiation therapy. As the patient was diagnosed with a pathogenic BRCA2 variant, a risk-reducing salpingo-oophorectomy was scheduled. However, liver metastases were detected on a preoperative PET-CT scan 7 months after surgery. Therefore, the patient was treated with olaparib followed by chemotherapy but died 15 months after surgery because of treatment inefficacy. Certain studies describe early TNBC recurrence in patients with pCR within 3 years after surgery, with cN1 or higher being common. Clinicians should be aware of potential TNBC recurrence in patients with pCR, especially within 3 years. Additionally, in the KEYNOTE-522 study, the hazard ratio for the pembrolizumab group compared to the placebo group was 0.73 in the event-free survival analysis of patients with pCR. Therefore, it is recommended that patients receive chemotherapy in combination with pembrolizumab.

An 80-year-old woman presented with blood-stained sputum. Computed tomography revealed the presence of multiple lung nodules. The patient underwent surgery for left breast cancer at 48 years of age. A transbronchial lung biopsy was performed to identify the primary tumor. The pathological diagnosis was adenocarcinoma and immunohistochemical staining indicated that the lung nodules were breast cancer metastases. Positron emission tomography revealed multiple metastases to the bones, skin, peritoneum, and mesenteric lymph nodes. The patient indicated that the quality of life was a critical factor in selecting therapy. Denosumab and an aromatase inhibitor were selected as the first-line systemic chemotherapies. The treatment resulted in tumor shrinkage that lasted for 3 years, after which the peritoneal metastases started to regrow. We recommended tegafur/gimeracil/oteracil as second-line chemotherapy, which the patient discontinued within 1 month because of severe side effects. We next administered fulvestrant, which resulted in the long-term shrinkage of most tumors without regrowth. This treatment did not negatively affect patients' quality of life. Some breast cancers recur ≥5 years after the primary surgery. Therefore, this is a very rare case of breast cancer recurrence with an interval of 32 years after the initial treatment.

The patient was a 52-year-old male, who, after experiencing lower back pain, underwent further investigation and was diagnosed with hepatocellular carcinoma with sacral metastasis. The hepatocellular carcinoma was a 9 cm tumor with a risk of rupture. Liver resection was performed, and lenvatinib was initiated at a dose of 4 mg/day postoperatively. Radical radiation therapy was then administered to address bone metastases. Lenvatinib was discontinued after 15 months due to skin disorders. Seven months have passed since the discontinuation of lenvatinib and 2 years since surgery. The patient's condition has progressed without any recurrence.

A 70-year-old man was referred to our hospital for an abnormal chest X-ray shadow. A chest CT scan showed a mass shadow with a cavitary lesion in segment 6 of the right lung. One year after radical resection(resection of the lower lobe of the right lung; pT2aN0M0, pStage ⅠB), the patient exhibited enlarged mediastinal lymph nodes and liver metastases, and postoperative recurrence was determined. After treatment with the immune checkpoint inhibitors nivolumab(Nivo)and ipilimumab(Ipi), the mediastinal lymph nodes and liver metastatic lesions shrunk markedly, and a complete response was achieved. The complete response persisted for over 21 months after treatment cessation and 30 months after starting treatment. Therefore, Nivo/Ipi therapy is useful for metastatic pulmonary pleomorphic carcinoma with low programmed cell death ligand-1 expression.

A 26-year-old male presented to a hospital with complaints of hemoptysis and right scrotal swelling. Computed tomography (CT) revealed right testicular swelling, multiple lung metastases, and small intestinal wall thickening. The patient's β-human chorionic gonadotropin, alpha-fetoprotein, lactate dehydrogenase, and hemoglobin levels were 103.3 ng/ml, 20.8 ng/ml, 300 U/l, and 11.3 g/dl, respectively. He underwent high orchidectomy after being diagnosed with a testicular tumor and multiple lung metastases. Histopathological examination revealed a mixed germ cell tumor (60% choriocarcinoma, 20% seminoma, 10% embryonal carcinoma, 10% mature teratoma, and 1% yolk sac tumor). As the patient exhibited active gastrointestinal hemorrhage requiring frequent blood transfusions, gastrointestinal endoscopy was performed to investigate its cause. When upper and lower gastrointestinal endoscopies revealed no bleeding, the patient was referred to our hospital for further examination and treatment. A small bowel endoscopy revealed a hemorrhagic jejunal mass. Because endoscopic hemostasis was challenging, we partially resected the small intestine. Pathological findings in the resected lesion were consistent with small intestinal metastasis of the testicular tumor. The tumor markers turned negative after four cycles of BEP and four cycles of TIP chemotherapy. He then underwent resection of the remaining lung tumor, and no residual tumor or recurrence was detected one year later.

We retrospectively analyzed the regions and perioperative outcomes associated with lymph node dissection in patients with prostate cancer. Of 543 patients who underwent robot-assisted radical prostatectomy for prostate cancer with or without lymph node dissection according to the modified D'Amico criteria, 333 (61.3%), 128 (23.6%), and 82 (15.1%) were classified into the non-dissection, limited dissection, and extended dissection groups, respectively. Lymph node metastasis was identified in eight patients : one in the limited dissection group and seven in the extended dissection group. Notably, all eight biopsies showed Gleason scores of 4＋4 or higher, and the initial prostate-specific antigen (PSA) concentration was ≥10 ng/ml in seven of these patients. Lymph node metastasis was detected in areas other than the obturator lymph nodes in five patients (62.5%). Although there was no significant difference in the rate of Clavien- Dindo grade ≥II complications among the three groups, six patients (7.3%) in the extended dissection group developed infectious lymphoceles. In the extended dissection group, the PSA progression-free survival (PSA-PFS) was significantly shorter in patients with than in those without lymph node metastasis (p＜0.001). Because lymph node metastases were rare in the limited dissection group in our cohort of patients with a high risk of localized prostate cancer, achieving a diagnosis seems difficult with limited dissection. By contrast, in the extended dissection group, the PSA-PFS prognosis was significantly worse in lymph node-positive cases. Therefore, considering the high complication risk of lymphoceles, extended dissection should be performed in patients with a high likelihood of lymph node metastasis.

A man in his 60s, who had undergone surgery for rectal cancer, liver metastases, and lung metastasis, had a past history of myocardial infarction and ventricular fibrillation with reduced cardiac functions. He was referred to our department because of a pulmonary nodule shadow in the S2 right upper lobe and a bronchial cast shadow along the B2 bronchus. Robot-assisted thoracoscopic right S2 segmentectomy was performed and intraoperative bronchoscopy revealed a polyp-like tumor within B2a. Then, B2a and B2b were resected and the tumor was removed into the surgical field. It was confirmed that there was no residue using a bronchoscope, and the bronchus was cut on the proximal side of B2 using an automatic suturing device. The final pathological diagnosis was rectal cancer with lung metastasis, and the endobronchial tumor showed necrotic tissue and bronchial stumps were negative.

A 36-year-old woman referred to our hospital for treatment of a mediastinal tumor. Contrast computed tomography (CT) scan was revealed a 31×21×25 mm mass in the anterior mediastinum, with low contrast, clear border, and a tendency to increase. On magnetic resonance imaging( MRI) examination, the anterior mediastinal tumor showed homogeneous high signal intensity on T1-weighted images and a combination of high and low signal intensities on T2-weighted images. A benign tumor was suspected, and surgery was performed for diagnostic and therapy. Histopathology did not demonstrate malignant cells and we diagnosed the tumor as dermoid cyst. The postoperative course was uneventful and the patient was discharged on 2nd postoperative day.

A 20-year-old female underwent a health checkup that revealed an abnormal shadow in the left upper lung field on a chest radiograph. A further examination with chest computed tomography( CT) showed a 25 mm solid tumor in the center of B1+2 in the left upper lobe. A biopsy of the tumor obstructing the left B1+2 was performed during bronchoscopy, and a pathological study diagnosed it as mucoepidermoid carcinoma of the lung. The patient underwent left upper lobectomy and lymph node dissection( ND2a-1). The pathological diagnosis was pT1cN0M0, indicating a predominance of high-grade lesions due to the presence of more solid components, including squamous and intermediate cells, than the mucous components. The nucleoli of these cells were distinct and were accompanied by cellular atypia. While most mucoepidermoid carcinomas of the lung are low-grade lesions, this case contained high-grade lesions, requiring careful postoperative follow-up.

A woman in her 60s with cirrhosis and hepatitis C virus with sustained virologic response underwent multiple local treatments for hepatocellular carcinoma (HCC) starting in April 20xx. Computed tomography in December 20xx+6 revealed HCC recurrence and mass in left kidney. Pathologic evaluation after partial nephrectomy led to the diagnosis of renal metastasis of HCC, and treatment with atezolizumab and bevacizumab was initiated. Complete response was observed with imaging after 13 cycles;however, computed tomography after 19 cycles revealed multiple metastatic lesions in left perirenal space. Multidisciplinary treatment implemented thereafter has led to disease control for about 18 months.