[A Case of Sclerosing Angiomatoid Nodular Transformation Resected for Suspected Relapse of Diffuse Large B-cell Lymphoma].

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.

[MSI-H Small Bowel Cancer with Peritoneal Dissemination Successfully Treated with Pembrolizumab-A Case Report].

A 52-year-old man was diagnosed with small bowel adenocarcinoma(T4aN1M0, Stage ⅢA, according to the Japanese colorectal cancer classification)and treated with partial resection of the small bowel in June 2014. He also received adjuvant chemotherapy(XELOX: 8 courses)after surgery. Three and a half years after the operation, peritoneal dissemination recurred, and he received bevacizumab plus XELOX therapy. The regimen was adjusted to a total of 11 courses because of the disease progression. The primary lesion showed MSI-H. The patient was started on pembrolizumab therapy in April 2019. The tumor responded well to pembrolizumab(maximum therapeutic effect: PR, 31% reduction), but a new lesion appeared 6 months after the start of this regimen. He continued pembrolizumab therapy for 14 months without adverse events since it appeared to be clinically effective. Although MSI-H small bowel cancers are rare, accurate screening is essential to not miss the opportunity to administer pembrolizumab.

[A Case of Sigmoid Colon Cancer Recurrence at the Hand-Sewn Anastomosis Site Originated from Tumor Implantation].

We report a case of anastomotic recurrence following laparoscopic sigmoidectomy with hand-sewn anastomosis, which was attributable to the implantation of exfoliated cancer cells. A 78-year-old man diagnosed with early colon cancer underwent endoscopic submucosal dissection(ESD); however, ESD was suspended due to infiltrated muscle fibers. Subsequently, he underwent laparoscopic sigmoidectomy with hand-sewn anastomosis, accompanied by D3 lymph node dissection. Histopathological findings revealed a well-differentiated tubular adenocarcinoma, pT2(MP), tub1>tub2>por2, ly0, v1, PM0, DM0, RM0, N0M0, pStage Ⅰ. The follow-up CT 6 months after surgery, showed enhanced wall thickening and irregular surface of the sigmoid colon. Colonoscopy revealed a type 2 tumor located on the anastomotic line. Based on the diagnosis of anastomotic recurrence, the patient underwent partial colectomy. Histopathological findings were similar to those of the primary tumor and suggested implantation of exfoliated cancer cells as the origin of anastomotic recurrence. Cancer cells had infiltrated all layers. In conclusion, we recommend the performance of appropriate operative procedures to prevent anastomotic recurrence, such as the cleaning of the anastomosed intestinal tract. Careful follow-up in colon cancer patients is of the utmost importance and the risk of anastomotic recurrence should always be considered.

Surgical strategies for localized colorectal amyloidosis.

BACKGROUND: Localized colorectal amyloidosis has a good prognosis, but cases involving bleeding or perforation may require surgery. However, there are few case reports discussing the differences in the surgical strategy between the segmental and pan-colon types. CASE PRESENTATION: A 69-year-old woman with a history of abdominal pain and melena was diagnosed with amyloidosis localized in the sigmoid colon by colonoscopy. Since preoperative imaging and intraoperative findings could not rule out malignancy, we performed laparoscopic sigmoid colectomy with lymph-node dissection. Histopathological examination and immunohistochemical staining revealed a diagnosis of AL amyloidosis (λ type). We diagnosed localized segmental gastrointestinal amyloidosis, because there was no amyloid protein in the margins, and the tumor was localized. There were no malignant findings. CONCLUSIONS: Unlike systemic amyloidosis, localized amyloidosis has a favorable prognosis. Localized colorectal amyloidosis can be classified into the segmental type, in which amyloid protein is deposited locally, and the pan-colon type, in which amyloid protein is deposited extensively in the colon. Amyloid protein causes ischemia due to vascular deposition, weakening of the intestinal wall due to muscle layer deposition, and decreased peristalsis due to nerve plexus deposition. No amyloid protein should remain outside the resection area. The pan-colon type is often reported to cause complications such as anastomotic leakage, and primary anastomosis should be avoided. On the other hand, if there is no contamination or tumor remnants in the margin, the segmental type may be considered for primary anastomosis.

A Case of Advanced Gastric Cancer with Peritoneal Metastasis Treated Successfully with Nivolumab.

Peritoneal metastasis (PM) is detected in 14% of gastric cancers at the time of initial diagnosis, with a median survival time of 4 months. A 66-year-old woman diagnosed with cT4a(SE) N2M1(LYN) cStage IV was treated with three lines of chemotherapy for a year. During the third line of chemotherapy, computed tomography (CT) scan revealed a large amount of ascites, periportal collar sign, and bilateral ureteral stenosis owing to PM. The tumor biomarkers (CEA and CA 19-9) remained elevated similar to the initial levels. The patient was administered 3 mg/kg nivolumab intravenously biweekly as the fourth line of chemotherapy. Three months after the nivolumab treatment, gastroscopy revealed an extreme reduction of the tumor size, while CT scan revealed the absence of ascites and a well-controlled tumor. There was no immune-related adverse event with nivolumab during and after the treatment, and performance status improved to 0. The patient has been alive for about 2.5 years since her first visit with her sixth line of chemotherapy (docetaxel). We report a case of advanced gastric cancer with PM that was treated successfully with nivolumab.