Genes that regulate immunological activities are transiently suppressed by epigenetic modification during the germinal center reaction of B cells and reactivated when B cells exit the germinal center. Mutations of EZH2 and other epigenetic modifier genes are frequently involved in the pathogenesis of follicular lymphoma and lead to silencing of the genes necessary for exiting the germinal center. Tazemetostat, an EZH2 inhibitor, has been approved for the treatment of follicular lymphoma with EZH2 gain-of-function mutations in Japan. Tazemetostat restores the expressions of MHC and CD58 in lymphoma cells and synergistically enhances the immune reactions of T and natural killer cells against lymphoma cells. Tazemetostat also induces lymphoma cells to secrete CCL17/TARC and enhances T-cell migration. CD58 and CCL17 are known to play central roles in the formation of T-cell-rich tumor microenvironment of Hodgkin lymphoma. We found that tazemetostat enhances the expression of genes overexpressed in Hodgkin/Reed-Sternberg cells. Epigenetic modifiers and new molecular targeted therapies are expected to provide new insights into the pathogenesis of lymphoma and mechanisms determining the histology of lymphoma.

We report a cases report of colorectal cancer who underwent repeated resection for peritoneal recurrences by laparoscopic surgery. In 2013, a 70-year-old woman diagnosed with an ascending colon cancer underwent laparoscopic right hemicolectomy. The pathological diagnosis was tub2, pT4aN1M0, Stage Ⅲb. Postoperative adjuvant chemotherapy(uracil and tegafur/Leucovorin)was administered. PET-CT performed at 25 months after the surgery because of CEA elevation. It revealed a peritoneal recurrence in the pouch of Douglas. The following peritoneal recurrences were removed by laparoscopic Hartmann's procedure. Chemotherapy(5-fluorouracil/levofolinate/oxaliplatin/bevacizumab)was administered 11 courses and after that chemotherapy(5-fluorouracil/levofolinate/bevacizumab)was administered 6 courses. PET-CT performed 37 months after the second surgery revealed a peritoneal recurrence near the right ovary in the pouch of Douglas. The following peritoneal recurrences was removed. Chemotherapy(tegafur/gimeracil/oteracil/bevacizumab)was administered 11 courses. The long-term survival has been continued for 7 years and 7 months after first operation. It was considered that laparoscopic surgery for peritoneal recurrence in colorectal cancer is contributed to one of the surgical procedures in selected patients.

A 78-year-old man without hepatitis virus B or C underwent right hemi-hepatectomy and lymph node dissection for a tumor 5 cm in diameter located in the hepatic hilum of the posterior segment of the liver with portal vein thrombi extending into the main portal trunk and a tumor 1.5 cm in diameter in the peripheral side of segment 5 of the liver. Histopathologically, the former was diagnosed as intrahepatic cholangiocarcinoma and the latter as hepatocellular carcinoma(HCC). Five months after the surgery, intrahepatic and lymph node metastases were diagnosed based on computed tomography(CT); therefore, chemotherapy with S-1 for 3 months and gemcitabine and cisplatin(GC)for 5 months was administered, after which the metastatic lesions were not detected. Nineteen months after the surgery, partial resection of segment 2 of the liver was performed for a tumor 3 cm in diameter, which was diagnosed as HCC histopathologically. Two years after the second surgery, 2 recurrent nodules in the liver in segments 3 and 4 were detected on CT. Platinum-based hepatic arterial infusion chemotherapy(HAIC)and transcatheter arterial chemoembolization(TACE)were performed, and chemotherapy with GC was then administered for 7 months. For a new tumor detected in segment 1 in the liver, TACE was performed 17 months after initial HAIC. Seventy-four months after the initial surgery, 5 new nodules less than 1 cm in diameter were detected, and chemotherapy with sorafenib was administered for 5 months, after which the patient died of coronavirus disease 2019.

Intraductal papillary neoplasm of bile duct(IPNB)is a papillary tumor that develops in the bile duct inside and outside the liver, and is a relatively new disease concept recognized as a precancerous/early cancer lesion of bile duct cancer.

A 60-year-old woman was not accompanied by any symptom. She had a gallstone which was identified 20 years prior. Ultrasonography performed by a local doctor revealed that the gallbladder was filled with small stones, and the patient was referred to our department for further examination and treatment for gallbladder stone. Tumor markers are elevated. Contrast- enhanced CT revealed gallbladder stones and thickening in the gallbladder body. PET-CT showed abnormal accumulation of FDG-PET with SUVmax 3.6 in the body of the gallbladder. With a diagnosis of gallbladder cancer, extended cholecystectomy and gallbladder bed resection with regional lymph node dissection were performed. The tumor was diagnosed histologically as small cell type neuroendocrine carcinoma of the gallbladder(pT2a[SS], pN0, pStage ⅡA; Japanese society of hepato-biliary-pancreatic surgery, the 7th edition). The postoperative course was uneventful. This patient has been followed up for 8 years without obvious signs of recurrence. R0 resection and lack of lymph node metastasis can allow long- term survival.

The case was a 72-year-old man who had been on medication due to chronic pancreatitis since 2009 and was referred to our hospital because dilation of the main pancreatic duct was shown by abdominal ultrasonography. The contrast CT scan of the abdomen showed a 30 mm in size, poorly enhanced tumor at the body of the pancreas, which was suspected to invasion the celiac artery, common hepatic artery, and splenic artery. EUS showed a hypoechoic tumor with a diameter of 29× 24 mm. ERCP showed disruption of the pancreatic duct in the body of the pancreas, and cytological examination of the pancreatic juice showed a suspicious positive result. We diagnosed unresectable locally advanced pancreatic cancer in the body of the pancreas and underwent chemotherapy(gemcitabine plus nab-paclitaxel: GnP). Contrast-enhanced CT after 6 courses of GnP showed tumor shrinkage. FDG-PET/CT revealed a slightly in fluorine-18-deoxyglucose(FDG)accumulation in the tumor, but no accumulation around the blood vessels. Based on the above, it was judged that the tumor was possible radical resection, and surgery was performed. Intraoperative frozen section examination revealed no malignant findings in the tissues surrounding the main artery near the pancreatic body cancer, and distal pancreatectomy was performed. Histopathologically, the tumor showed findings of tubular adenocarcinoma, and the histological response to neoadjuvant therapy was Grade 2. We report a case in which conversion surgery was possible by chemotherapy.

We report a case of early gastric cancer with Adachi Type Ⅵ vascular anomaly treated by laparoscopic distal gastrectomy. An 81-year-old woman was admitted because of anorexia, and was diagnosed with early gastric cancer. Preoperative MDCT revealed Adachi Type Ⅵ vascular anomaly, where the hepatic artery does not appear at the superior border of the pancreas. The patient was treated successfully with laparoscopic distal gastrectomy with D1+lymph node dissection. At surgery, we identified the portal vein, then, dissection of No. 8a lymph nodes was performed. The postoperative course was uneventful and the patient was discharged 10 days after surgery. The final pathology result showed gastric cancer, M, Less, Type 0-Ⅱc+Ⅲ, 58×50 mm, tub1>pap, pT1a(M), Ly0, V0, pN0(0/40), H0, P0, M0, pStage ⅠA. We understand the arterial running pattern before surgery by using MDCT, and performed laparoscopic surgery safely.

We report a case of sclerosing angiomatoid nodular transformation(SANT)5 years after remission of diffuse large B-cell lymphoma(DLBCL). A 64-year-old woman was diagnosed a nodular mass at the spleen by a contrast-enhanced CT scan 5 years after the relief for DLBCL. The mass showed accumulation of FDG. Because the possibility of the recurrence of malignant lymphoma could not be ruled out, laparoscopic splenectomy was performed for diagnosis and treatment. Immunohistologically, the resected mass revealed 3 different vascular components pattern(CD31, CD34 and CD8), so we diagnosed SANT. It is difficult to distinguish from malignant lymphoma or cancer even with various examination, so laparoscopic splenectomy is useful for diagnosis and treatment.

The patient was a 60s man, whose chief complaint of melena and weight loss. He visited our hospital, and further evaluation revealed rectal cancer(Rb)invading the prostate with obturator lymph node metastasis. The clinical diagnosis was T4b (prostate)N3M0, Stage Ⅲc. He was administered 4 courses of CAPOX plus bevacizumab. After chemotherapy the primary tumor and lymph nodes showed PR, the diagnosis of ycT4bN1bM0, Stage Ⅲc. We performed robot-assisted total pelvic exenteration. He has been cancer-free for 5 months.

The Japanese gastric cancer clinical practice guideline recommends FOLFOX as one of the first-line chemotherapy for advanced gastric cancer. Since FOLFOX is administered intravenously, it is helpful for patients who have difficulty in oral intake. Herein, we report a patient in which FOLFOX was significantly effective after failure to treatment with S-1 plus CDDP. A 75-year-old gastric cancer patient with paraaortic lymph node metastasis and multiple liver metastases(Stage ⅣB)was treated. Severe stomatitis and impaired consciousness due to dehydration appeared after administration of S-1 plus CDDP. After his general condition recovered, we changed his regimen to FOLFOX. No serious adverse events were observed, and partial response was achieved after 4 courses of treatment. Partial response was maintained until the onset of oxaliplatin drug allergy in the 10th course. FOLFOX is a promising option for patients with difficulties in oral intake.

An 82-year-old woman presented to our hospital with chief complaints of lower abdominal pain and nausea. Contrast- enhanced CT showed ileus of sigmoid colon cancer and a solitary splenic tumor. A metallic stent was placed for the primary lesion. FDG-PET showed high FDG accumulation in the solitary splenic tumor, and synchronous solitary splenic metastasis was diagnosed. Laparoscopic sigmoid colectomy and laparoscopic splenectomy were performed without changing the intraoperative position or port arrangement. Postoperative progress was favorable. The patient was discharged 9 days after surgery, and no sign of recurrence has been observed to date, at 4 months after surgery. Solitary splenic metastasis of colorectal cancer is extremely rare. This is the first case report of synchronous solitary splenic metastasis of colorectal cancer treated with laparoscopic resection in Japan. This procedure is considered effective and minimally invasive. We review and discuss the Japanese literature on this rare disease.

A 65-year-old woman was admitted to our institution with sonography results indicating a caudate lobe mass. CT showed a large low-density mass in the caudate lobe, extensively involving the inferior vena cava and main portal vein. Moderately differentiated adenocarcinoma was found on transcutaneous biopsy. We therefore regarded this tumor as a severe locally advanced hilar cholangiocarcinoma and initiated gemcitabine/cisplatin combined chemotherapy. The tumor gradually reduced in size. However, after 28 courses of treatment, CT showed persistent tumor invasion in the left trunk of the portal vein and inferior vena cava invasion in succession in the middle; the tumor had not yet invaded the left hepatic vein. Owing to myelosuppression and general malaise, it was difficult to continue chemotherapy. After 32 courses of treatment, the patient underwent a left trisegmentectomy with combined resection of the portal vein and inferior vena cava. Postoperative microscopic findings revealed no apparent invasion of the tumor in the inferior vena cava, thus suggesting successful R0 resection. The patient is alive without recurrence 18 months postoperatively.

A 37-year-old pregnant woman arrived at our hospital with an abnormal mammogram.

Preemptive skin treatment led by nurses and pharmacists was started for patients with metastatic colorectal cancer (mCRC)who received anti-EGFR antibody treatment. Incidence of skin-related toxicities, amount of topical moisturizers used, and administered cycles of anti-EGFR antibody were retrospectively compared between a preemptive skin treatment group and a control group. Thirty-four mCRC patients before the introduction of preemptive skin treatment led by nurses and 23 mCRC patients treated with preemptive skin treatment led by nurses were evaluated. The incidence of 6- and 12- week Grade 2 or higher skin-related toxicity was 23.5% in the control group and 8.7% in the preemptive group(p=0.18), and 67.7% in the control group and 30.4% in the preemptive group(p=0.0076), respectively. Mean amounts of moisturizer used were both lower in the control group than in the preemptive group at both 6 weeks and 7-12 weeks(6 weeks; 275 g vs 550 g, p=0.036, 7-12 weeks; 575 g vs 1,175 g, p=0.013). However, the amount of topical steroid used was similar in both groups. Preemptive moisturizer skin treatment led by nurses and pharmacists may decrease the incidence of skin- related toxicity.

Astroblastoma is an extremely rare primary brain tumor accounting for 0.45 to 2.8% of all neuroglial tumors and usually occurs in pediatrics and young adults. The natural history of astroblastoma still remains unknown. In the World Health Organization (WHO) classification of tumors of the central nervous system, astroblastoma is classified as other neuroepithelial tumors and standard treatment other than surgery has not been established. As molecular and genetic diagnosis becomes more important in the latest WHO classification of brain tumors, the development of therapeutic options based on the information of molecular genetics are expected. Here we report a case of astroblastoma in a 49-year-old male. Small tumor was discovered by coincidence during his check-up following traffic accident, but three months later, tumor bleeding with cystic enlargement resulted in disturbance of consciousness. Initial diagnosis of low grade astroblastoma with BRAFV600E mutation was made. After 1 year, local tumor recurrence was observed. The histological diagnosis at recurrence was high grade astroblastoma. We here, discuss about diagnosis, treatment and the possibility of usefulness of molecular genetic analysis for astroblastoma with some literature review. (Received 10 August, 2021; Accepted 15 December, 2021; Published 1 April, 2022).

Concomitant pancreatic ductal adenocarcinoma (PDA) is observed in a subset of patients with intraductal papillary mucinous neoplasm (IPMN) of the pancreas, and early detection of those progressing lesions is difficult. We present a case with a de novo carcinoma in situ (CIS) discovered incidentally around the resection margin of IPMNs. A man in his 70s with a history of acute pancreatitis at the age of 50 years and no family history of PDA had a pancreatoduodenectomy for three isolated branch duct IPMNs that caused recurrent pancreatitis. During the 2-year follow-up period, the index lesion in the pancreatic head grew significantly, whereas the other cysts remained small and without mural nodules. The majority of the cysts are histologically composed of low-grade dysplasia and are classified as gastric-type IPMN. CIS with nuclear overexpression of p53 was located in the main pancreatic duct and adjacent brunch duct, which involved the pancreatic resection margin. The precise pathological analysis combined with multiregion sequencing revealed the CIS harbored KRAS G12V and TP53 R248W. Conversely, IPMNs contained GNAS mutant cells as well as components containing additional KRAS mutations. These findings suggested that the CIS formed independently of the multiple IPMNs and appeared to be an early manifestation of concomitant PDA with coexisting IPMNs. Despite widespread agreement on the resection of the radiographically significant IPMN lesion (s), the latent invasive cancer was not eradicated. A detailed pathological and molecular assessment of the resected materials may aid in a better management strategy for concurrent lesions.

A 65-year-old man had unresectable intrahepatic cholangiocarcinoma with a malignant biliary stricture. We used an endoscopic plastic stent to drain the bile. Despite receiving standard chemotherapy, the tumor eventually progressed and cancerous peritonitis developed. We had to exchange plastic stents frequently because of stent occlusion. We had a re-biopsy with EUS-FNA and tested for microsatellite instability, which came back as MSI-high. We administered pembrolizumab, which resulted in a significant reduction of tumor size. We were able to administer long-term chemotherapy without serious side effects by repeatedly exchanging plastic stents for stent occlusion. He has maintained partial response for more than 20 months after receiving pembrolizumab.

A 72-year-old woman was diagnosed with extranodal NK/T cell lymphoma of the right nasal cavity and received sequential radiochemotherapy comprising focal radiotherapy and THP-COP chemotherapy. Showed a complete tumor response to the treatment; however, the tumor recurred in the contralateral right nasal cavity 15 years after the initial treatment. This was judged to be a marginal recurrence in the radiation field. After four cycles of dexamethasone, methotrexate, ifosfamide, L-asparaginase, and etoposide (SMILE) chemotherapy, a second complete response was achieved. It is possible that another recurrence occurs in the future, and if the lesion is localized at the time of recurrence, it may be possible to control the disease again. Careful follow-up is considered necessary.