With the increasing use of robot-assisted surgery, partial nephrectomy is recommended for small renal tumors(T1a)with a tumor size of 4 cm or less and is now considered a standard treatment. However, with the rise in incidental detection of small renal tumors during routine screenings, especially in elderly patients or those with comorbidities who may hesitate to undergo general anesthesia, there is a growing need for alternative treatments such as focal therapy to partial nephrectomy. The main methods of focal therapy include ablation techniques such as cryotherapy and radiofrequency ablation. Recently, stereotactic body radiotherapy has also been approved for insurance coverage, emerging as a minimally invasive option for renal cell carcinoma with a tumor size of 5 cm or less. Additionally, although not a focal therapy, active surveillance is also considered an effective option for very small renal tumors. Among these various treatment options, shared decision making between patients and healthcare providers, considering factors such as tumor characteristics and patient-specific conditions, is considered crucial in determining the appropriate treatment strategy for small renal tumors. In the absence of large-scale prospective comparative trials on partial nephrectomy, ablation therapy, stereotactic radiotherapy, and active surveillance, this paper provides an overview of the characteristics of each treatment modality and their respective outcomes and discusses the future perspectives in the treatment of small renal tumors.

While the widespread use of PSA testing has led to early detection of prostate cancer, the increased diagnosis of clinically insignificant cancers has led to overtreatment, such as prostatectomy and radiation therapy. The side effects of this overtreatment may lead to a decline in the quality of life of patients. Therefore, organ- preservation strategies for localized prostate cancer are expected to combine cancer control with functional preservation and maintenance of quality of life. In this regard, active surveillance and focal therapy are ideal concepts in organ preservation. Active surveillance is an established strategy for low-risk and some intermediate-risk prostate cancers, and focal therapy is not yet recommended as primary therapy for localized prostate cancer in various guidelines. However, focal therapy as a primary treatment targets clinically significant cancer for intervention, while active surveillance is applied to manage other insignificant cancers, potentially highlighting a compatibility between the 2 approaches. We proposed a treatment strategy in which focal therapy is performed on localized lesions and then active surveillance is continued again when disease progression is observed during active surveillance. We believe that this approach is an effective way to avoid overtreatment and to maintain the patient's quality of life for a long time. Although uniformity in diagnostic imaging quality and establishment of treatment indication criteria are needed to realize this approach, it may become a new approach to prostate cancer treatment in the future.

CPX-351 (Vyxeos®), a liposomal formulation used in the treatment of acute myeloid leukemia, has been associated with cutaneous adverse events, particularly purpura, in previous clinical trials. We present the case of a 73-year-old woman with refractory acute monocytic leukemia and leukemia cutis, who was treated with CPX-351 as salvage induction therapy. Following treatment, the extramedullary lesions resolved; however, some skin lesions developed into pustular eruptions. These pustules appeared during the neutropenic phase, and cultures ruled out infection, leading to the diagnosis of sterile pustulosis. Supportive care, including skin care measures and application of antibiotic ointment, allowed for continued treatment, and the pustules resolved after crusting. To our knowledge, this is the first reported case of sterile pustulosis associated with CPX-351 treatment, highlighting the importance of early detection and appropriate management of skin complications for the successful continuation of therapy.

The case was a 77-year-old man. He presented with abdominal pain and melena to our hospital. Abdominal CT showed thickening of the small intestinal wall and findings of intraperitoneal free air. Suspecting peritonitis due to small intestinal tumor perforation, we performed an emergency surgery. A ruptured tumor measuring 50 mm in diameter was found in the jejunum about 15 cm from the Treitz' ligament and the partial resection of the small intestine was performed. Histopathology revealed fistulous necrosis within the tumor, and immunostaining was positive for KIT and CD34, leading to the diagnosis of jejunal GIST. He was evaluated as high risk for recurrence and was indicated for adjuvant chemotherapy. He is currently taking imatinib and is being followed up for 6 months without recurrence. Although diagnosing GIST of small intestine can be difficult, GIST of small intestine with perforation is at high risk of recurrence and rezuires adjuvant chemotherapy. Emergency surgical diagnosis should not be hesitated.

A 75-year-old woman was admitted to our hospital with a complaint of jaundice and elevated liver enzyme levels. She was diagnosed with pancreatic head carcinoma after examination. She had undergone massive resection of the small intestine due to thrombosis of the superior mesenteric artery at 48 years of age, and the remaining ileum was approximately 70 cm in length. As the patient had no symptoms of short bowel syndrome, we deemed surgery to be feasible. We performed a subtotal stomach-preserving pancreaticoduodenectomy with gastropancreatic anastomosis to preserve the longest possible effective small intestine length. Although surgical site infection was observed postoperatively, parenteral nutrition was discontinued on the 24th postoperative day, and the patient was discharged on the 54th postoperative day. The final diagnosis was pancreatic head carcinoma, pT3N0M0, pStage ⅡA. At 54 months postoperatively, the patient is alive, has no recurrence, and is in a good nutritional condition. Although patients are prone to nutritional disorders after massive resection of the small intestine or pancreaticoduodenectomy, the nutritional status should be maintained using a surgical technique that can leave a long effective residual small intestine length.

The 1-year survival rate of patients with unresectable hepatocellular carcinoma is less than 50%, which indicates a poor prognosis. Recently, the combination of atezolizumab and bevacizumab has improved the prognosis of patients with advanced hepatocellular carcinoma and has become the first-line treatment for unresectable hepatocellular carcinoma. However, there are few reports on conversion surgery after chemotherapy for unresectable hepatocellular carcinoma. Here, we report the case of a 92-year-old man with no significant complaints. During follow-up, the tumor was found to be enlarged, and abdominal MRI revealed a tumor in S4-1 and S8 of the liver. We diagnosed the tumor as an unresectable hepatocellular carcinoma. After atezolizumab and bevacizumab combination therapy, we evaluated the partial response(PR)using the response evaluation criteria in solid tumors(RECIST)and performed laparoscopic cholecystectomy and left lobectomy. There are no established indications for conversion surgery for unresectable hepatocellular carcinoma after combination therapy with atezolizumab and bevacizumab, and more cases should be studied to determine the indications and optimal timing of conversion surgery.

Drug therapy for hepatocellular carcinoma has made remarkable progress in recent years, and surgical resection of tumors that respond well to drug therapy has been performed in some cases. We report a case of hepatocellular carcinoma with hepatopulmonary metastases that was successfully treated with atezolizumab plus bevacizumab and surgically resected. The patient was a 56-year-old man who underwent a posterior segmentectomy and was diagnosed with hepatocellular carcinoma. Three months after the surgery, CT revealed multiple liver and lung metastases. Fifteen courses of atezolizumab and bevacizumab were administered. Drug therapy was effective, and most metastases disappeared; however, the liver metastasis remained in segment 8/4, and partial resection of the liver was performed. Recurrence was observed in liver segment 2 after 1 year and 2 months, and partial resection of the liver was performed. The patient is currently alive and recurrence-free 3 months after the surgery. With progress in drug therapy, multimodal treatment for unresectable hepatocellular carcinoma is expected to improve the prognosis.

The patient is a 66-year-old man. He underwent a total of 9 courses of GCD therapy(gemcitabine+cisplatin+durvalumab)for intrahepatic cholangiocarcinoma with direct invasion of the greater omentum and abdominal wall and surrounding peritoneal dissemination. The tumor had shrunk and was judged to be curative, and laparoscopic hepatic S4a/S5 subsegmentectomy and S6 partial hepatectomy were performed at 8 months after the initial diagnosis. On the 24th postoperative day, pruritic petechial erythema appeared on the abdomen and lower extremities, some of which were accompanied by blisters. The patient tested positive for anti-BP180 antibody and was diagnosed as bullous pemphigoid. The skin rash improved after systemic steroid administration, and the patient is currently under observation. Bullous pemphigoid is a rare immune-related adverse event, but careful observation of skin symptoms is necessary for early detection.

The patient was a 66-year-old man. He came to our hospital because of abdominal discomfort. A CT scan revealed hypovascular tumors of about 70 mm in the S4/5 and 16 mm in the S6 of the liver. The S4/5 tumor was directly invasive into the greater omentum and abdominal wall, and a nodule suspected of peritoneal dissemination was observed around the tumor. Based on tumor biopsy results, a diagnosis of intrahepatic cholangiocarcinoma(ICC), cT3N0M1, Stage ⅣB was made. A total of 9 courses of GCD therapy(gemcitabine+cisplatin+durvalumab)were performed for ICC and the tumor was found to have shrunk, and the S6 tumor was obscured. The FDG-PET/CT scan also showed similar results, and the patient was judged to be curative, and surgery was performed 8 months after the initial diagnosis. Laparoscopic hepatic S4a/5 subsegmentectomy and S6 partial hepatectomy were performed. Intraoperative findings showed no peritoneal dissemination, and cytology of washed ascites was negative. Histopathological examination did not reveal any tumor cells, and the patient was judged to have a pathological complete response(pCR). There are few reports of ICC with pCR after GCD therapy, and we report this case here with a review of the literature.

A 50-year-old female presented with abdominal pain. Upper gastrointestinal endoscopy revealed a 30 mm ulcerative lesion extending from the duodenal bulb to the descending portion, and biopsy confirmed poorly differentiated adenocarcinoma. Abdominal contrast-enhanced CT scan showed an hypovascular tumor in the pancreatic head with suspected invasion into the duodenum, along with enlarged #8 lymph node. PET-CT revealed abnormal uptake in the pancreatic head and #8 lymph node. She underwent robotic pancreaticoduodenectomy for a diagnosis of pancreatic head cancer with lymph node metastasis. Histopathological examination revealed proliferation of atypical cells in acinar, trabecular, ribbon-like anastomosing, and tubular structures. Immunohistochemistry showed positivity for Bcl10(60%), INSM1(20%), Ki-67 index of 45%, and coexistence of invasive ductal adenocarcinoma(20%). Based on these findings, the tumor was diagnosed as predominantly acinar cell carcinoma with invasive ductal adenocarcinoma and neuroendocrine tumor. Lymph node metastasis was positive showing Bcl10-positive acinar cell carcinoma. Four months postoperatively, recurrence was detected in the para-aortic lymph nodes, confirmed by biopsy to be acinar cell carcinoma. Chemotherapy was initiated but discontinued due to tumor progression leading to best supportive care.

A 66-year-old woman presented with discharge of necrotic tissue and bleeding from the vagina during uterine cancer screening. She was diagnosed with lower rectal cancer cT4b(vagina)N3M0, cStage Ⅲc. As the tumor protruded into the lumen from the posterior vaginal wall, preservation of the anterior vaginal wall was challenging. Robot-assisted total pelvic exenteration with vulvectomy was performed. The patient was discharged without any apparent postoperative complications. Upon histopathological examination, the lesion was identified as being pT4bN0M0, pStage Ⅱc. Six months after the surgery, no recurrence or decline in the performance status was noted.

An 81-year-old man underwent a partial laparoscopic hepatectomy for tumors in the S7 segment of the liver and was diagnosed with moderately to poorly differentiated hepatocellular carcinoma(HCC). Two years and 10 months later, MRI identified a 10 mm tumor in the S8 segment of the liver, indicative of highly differentiated HCC. Colorectal endoscopy subsequently revealed a submucosal tumor in the transverse colon, with biopsy findings showing features similar to the previous HCC. Immunohistochemistry results showed CDX2-negative, CK20-negative, and hepatocyte paraffin 1(Hep Par 1)-positive markers, confirming a diagnosis of metachronous colorectal metastasis of HCC. The patient underwent laparoscopic partial hepatectomy of the S8 segment and right hemicolectomy. Histopathological evaluation identified the liver tumor tissue as highly differentiated HCC, suggestive of metachronous multicentric recurrence. In contrast, the colonic tumor was characterized as moderately to poorly differentiated HCC, resembling the initial HCC. As there was no serosal exposure or lymph node metastasis, metachronous hematogenous recurrence of HCC in the colon was observed.

Epidermoid cysts originating from the upper urinary tract are extremely rare, and only five cases have been reported previously. We report a rare case of epidermoid cyst that originated from the right ureter : A 76-year-old man presented with asymptomatic gross hematuria. Computed tomography showed a right ureteral tumor (14×8 mm in size). Retrograde pyelography showed a defect (14 mm diameter) of the contrast medium in the same region. Urinary cytological examination indicated class III. A ureteral tumor was clinically indicated, and retroperitoneoscopic-assisted radical nephroureterectomy was performed. Postoperative histopathological examination of the resected specimen showed ureteral epidermoid cysts without any malignancy.

Ganglioneuroma, an infrequent benign tumor that originates from the sympathetic nervous system, is usually a solitary occurrence and rarely occurs at multiple sites. Here, we report a case of retroperitoneal ganglioneuroma with multifocal bone involvement in a middle-aged woman. A 43-year-old female was incidentally diagnosed with a retroperitoneal tumor on abdominal ultrasonography. Contrast-enhanced computed tomography revealed a retroperitoneal tumor that was 11 cm in diameter above her left kidney and multiple bone lesions. Fluorodeoxyglucose positron emission tomography (FDG-PET) showed a slightly high FDG uptake (standardized uptake value (SUV) max, 3.7) in the retroperitoneal mass and mild accumulation in the L1 vertebral body, zygoma, acetabulum, and calcaneus. Biopsies were performed for the retroperitoneal and lumbar spine tumors, both of which were diagnosed as ganglioneuromas. Total surgical resection is the standard treatment of this condition ; however, for this patient, it was difficult to remove all the tumors, and the ganglioneuromas generally followed a benign course. Therefore, a watchful waiting approach was chosen and no tumor growth was observed three years after her first visit to our hospital.

The tumor microenvironment (TME) includes immune cells, cancer-associated fibroblasts (CAFs), endothelial cells, pericytes, and more. Previously, these non-cancer cells were considered inactive components in cancer pathology. However, it has become evident that these cells and their secretions play crucial roles in cancer progression. To unravel the complexity of the TME and elucidate its mechanisms, microphysiological systems (MPS) have gained attention. An MPS is defined as "a microscale cell culture platform for in vitro modeling of functional features of a specific tissue or organ of human or animal origin", allowing for the control of the chemical or physical conditions of the TME and the analysis of the responses of cancer cells and surrounding cells. In recent years, the incorporation of vascular networks into tumor MPS has enabled more accurate assessments of the dynamics within the TME. This review provides an overview of the latest research on cancer MPS with vascular networks and the cellular and molecular dynamics within the TME.

A 57-year-old male patient with a history of daily contact with stray cats was transferred to our hospital with weakness in the left limb and mild disturbance of consciousness. At presentation, he had no fever or signs of meningeal irritation. Cerebrospinal fluid examination revealed lymphocytic pleocytosis; however, the cerebrospinal culture was negative. Computed tomography of the thorax and abdomen showed no abnormalities. Gadolinium-enhanced brain MRI revealed multiple contrast-enhanced lesions in the periventricular white matter and enhanced lateral ventricles. Under the suspicion of cerebral toxoplasmosis, trimethoprim-sulfamethoxazole was administered, but his symptoms gradually worsened. Histopathological findings of the first brain biopsy did not reach the definitive diagnosis. The tissue culture detected Propionibacterium acnes. Despite changes in antibiotics (ceftriaxone and ampicillin), his symptoms progressed. The second brain biopsy revealed diffuse proliferation of atypical glial cells with irregular size of nuclei and necrosis. The diagnosis was glioblastoma, IDH-wild type, CNS WHO grade 4. The radiological findings in this case were initially recognized as isolated multiple lesions with surrounding vasogenic edema, but we authors should have suspected the brain tumor which spreads through the corpus callosum. Multifocal glioblastomas, a rare type of glioblastoma, has worse prognosis than unifocal glioblastoma. This case also emphasizes the importance of the appropriate timing of brain biopsy and careful validation of biopsy sampling.

We report a case of intrapancreatic bile duct solitary recurrence 4 years postoperatively for pT2 gallbladder cancer. A 58-year-old woman underwent laparoscopic cholecystectomy for a growing gallbladder polyp. Her histopathological findings included well-differentiated adenocarcinoma, pT2a, ly0, v0, ne0, pCM0, pEM0, R0. Consequently, gallbladder bed resection, extrahepatic bile duct resection, choledochojejunostomy, and lymph node dissection were performed. Following which, residual cancer was not reported. Postoperatively, abdominal computed tomography(CT)scans were performed at 6-month intervals. A 3-cm mass with poor contrast was observed in the pancreatic head 4 years postoperatively without main pancreatic duct dilation or pancreatic parenchymal atrophy, and the mass was considered as a recurrent nodule of gallbladder cancer. The recurrent mass could no longer be identified after three courses of GEM+CDDP combination therapy. Subsequently, the disease was determined to be curable, and a pancreaticoduodenectomy was performed. Her postoperative course was uneventful, and the patient was discharged after 30 days. A clearly demarcated white nodular mass measuring 5 mm in diameter was observed in the posterior part of the pancreas, which was a poorly differentiated adenocarcinoma. In this case, the tumor was macroscopically and histologically atypical for primary cancer and was considered a gallbladder cancer recurrence with its main site in the bile duct.

A 81-year-old woman was referred to our department for further examination and treatment after upper gastrointestinal endoscopy revealed a type 3 tumor in the antrum. CT scan revealed a primary tumor with extramural invasion in the antrum and large lymph nodes bordering the pancreas, as well as in the right side of cardia. A diagnosis of advanced gastric cancer cT4aN2M0, cStage Ⅲ was made. She was administered chemotherapy with nivolumab and SOX. After 2 courses of treatment, CT scan showed marked reduction of the primary tumor and lymph nodes. Therefore, laparoscopic gastrectomy(D2 dissection+Roux-en-Y reconstruction)was performed. Histopathological findings showed that the primary tumor was confined to the sub serosal tissue and no lymph node metastases were observed. The patient is currently alive without recurrence and treated with S-1 monotherapy. Chemotherapy with nivolumab and SOX is considered to be an effective treatment strategy for advanced gastric cancer with advanced lymph node metastases.

We report a case of IPMC complicated with obstructive pancreatitis due to perforation of the duodenum, in which radical surgery was performed. The patient was a 50-year-old man. He was referred to his previous doctor for a thorough examination of jaundice and liver damage. ERCP showed a tumour exposed in the duodenal bulb and IPMC was suspected, but biopsy showed no malignant findings. The patient was treated for obstructive pancreatitis, but the inflammatory response remained elevated. On imaging evaluation, inflammation around the pancreatic body tail remained, but inflammation around the portal vein was relatively mild. The pancreaticoduodenectomy was performed with sub-total gastric preservation. The pathology results showed a diagnosis of IPMC, with destruction of the duodenal wall due to compressible intraductal tumour growth, and a wide area of acute inflammation. The patient was treated with S-1 as adjuvant post-operative chemotherapy for 6 months and is currently recurrence-free.

A man in his 60s presented with jaundice. He was diagnosed with BR pancreatic head cancer with SMV infiltration. He underwent subtotal stomach-preserving pancreaticoduodenectomy(SSPPD)and SMV resection. He had an uneventful postoperative course and was discharged on day 13. Pathology revealed T4N1(3/28)M0, Stage Ⅳa. After adjuvant chemotherapy, a solitary left lung nodule was detected 2 years and 6 months postoperatively. It was diagnosed as recurrence. After chemotherapy, thoracoscopic partial lung resection was performed 3 years and 6 months postoperatively. Three months later, another solitary nodule was found in the left lung. Thus, a second thoracoscopic partial lung resection was performed 6 years and 1 month postoperatively to remove the lung metastasis. There has been no recurrence since, and the patient has achieved long-term survival of over 9 years after the initial surgery. This is a rare case of long-term survival after 2 metastasis resections, which we report with a brief literature review.