[A Case of Curative Resection of a Retroperitoneal Liposarcoma].

A 55-year-old woman had been admitted to a hospital with abdominal bloating. Retroperitoneal liposarcoma was suspected and diagnosed as not resectable. She was then referred to our hospital with dyspnea and difficulties with movement due to the huge mass. An abdominal CT revealed a large mass originating in the left retroperitoneum. The tumor occupied most of the abdominal cavity, resulting in the displacement of her organs. However, there was no evidence of infiltration of the tumor into the aorta and inferior vena cava. Under a provisional diagnosis of retroperitoneal liposarcoma, a surgical resection was undertaken. The resected specimen had a maximum diameter of 48 cm and weighed 14 kg. Histopathological examination revealed a differentiated liposarcoma. The patient remains alive 6 months after the operation, without recurrence.

[A Case of Malignant Peripheral Nerve Sheath Tumor of the Anus Resected by Robot Assisted-APR].

An 81-year-old female visited a local hospital with complaints of anal pain. A tumor was found on the right side of her anus, and the histopathological diagnosis was a non-epithelial malignant tumor. Therefore, the patient was referred to our hospital. Result of imaging inspection revealed that the tumor had invaded the lower rectum, but had not distantly metastasized. Based on the findings of another biopsy, the patient was diagnosed with a malignant peripheral nerve sheath tumor (MPNST). Robot-assisted abdominoperineal resection(D1)was performed, and the lesion was resected without any pathological remnants. During the postoperative period, the patient developed perineal wound infection. Subsequently, the patient was discharged from the hospital on postoperative day 10. At the 6-month postoperative follow-up, no recurrence was noted. Most MPNSTs occur in the limbs, trunk, and neck. MPNST in the primary gastrointestinal tract or in the vicinity of the gastrointestinal tract is relatively rare, and in principle, combined resection of the intestinal tract is required for surgical treatment. Here, we report a case of MPNST that occurred near the anus and infiltrated to the lower rectum and was completely resected by robot-assisted abdominoperineal resection.

[A Case of Synchronous Gallbladder Metastasis Originating from Advanced Gastric Cancer].

Gallbladder metastasis from gastric cancer is often found accidentally during postoperative pathological examinations, and its preoperative diagnosis is very difficult. There are a few reports in diagnostic imaging, and it is well known to have a very poor prognosis. There have been 13 reports on gallbladder metastasis from gastric cancer in the Japanese literature. Among the 13 reports, 10 cases were diagnosed with gallbladder metastasis synchronously and only 1 case was diagnosed as gallbladder metastasis before surgery. One case was reported as hematogenous metastasis, and 9 cases were reported as lymphoid metastasis. In total, 7 patients died, all within the first year after surgery. We experienced a case of synchronous gallbladder metastasis from gastric cancer.

[The Outcome of Preoperative Chemoradiotherapy for Advanced Lower Rectal Cancer-The Possibility of an Omission of the Lateral Dissection].

The objective of this study was to evaluate the outcomes of selective LPLN dissection(LPLD)based on pretreatment imaging in patients with advanced low rectal cancer treated with pre-operative CRT. We reviewed 32 patients without suspected LPLN metastasis based on the MDCT or MRI results before CRT. These patients underwent total mesorectal excision (TME)without LPLD. The clinical characteristics and oncological outcomes were examined. In all cases, the per-protocol treatments were completed. Tumor recurrence occurred in 14 patients at the liver(3 cases), the lung(7 cases)and the local sites(4 cases). Of the 4 cases with pelvic recurrence, no recurrence was found in the lateral lymph node area. Under the condition that pre-operative chemoradiotherapy is to be performed for advanced lower rectal cancer with negative lateral lymph node metastasis, a lateral dissection could be omitted.

[A Case of Low-Grade Appendiceal Mucinous Neoplasm Complicated by Pseudomyxoma Peritoneri Successfully Treated with Cytoreductive Surgery and Intraperitoneal Chemotherapy].

We experienced a case of low-grade appendiceal mucinous neoplasm complicated by pseudomyxoma peritonei that was successfully treated with cytoreductive surgery and early postoperative intraperitoneal chemotherapy. The patient was a 26- year-old man with massive ascites and a swollen appendix on the computed tomography(CT). The appendix was a cystic mass of 5 cm in size. The entire parietal peritoneum, omentum, stomach, spleen, gall bladder, and entire colon were covered with numerous mucous nodules. Total colectomy, total gastrectomy, splenectomy, cholecystectomy, total omentectomy, parietal peritonectomy, ileostomy, and intraperitoneal irrigation were performed. The pathological diagnosis was low-grade appendiceal mucinous neoplasm. Postoperative intraperitoneal chemotherapy with cisplatin and mitomycin C was performed. A residual tumor was found on the dorsal side of the hepatoduodenal ligament 3 months postoperation on the CT. The residual tumor was successfully excised via a concomitant resection of the hepatic caudate lobe. Postoperative intraperitoneal chemotherapy was then performed. No recurrence was found at 8 months postoperation. The addition of early postoperative intraperitoneal chemotherapy improved the patient's quality of life in a short period. This could be one of the treatment options.

[Analysis of Palliative Stents for Colonic Stenosis Due to Extracolonic Cancers].

We retrospectively reviewed 13 patients in whom endoscopic stenting for colonic stenosis due to extracolonic cancers(non- CRC group)was attempted between July 2012 and January 2018. There were 5 men and 8 women, with a median age of 69 years. Primary malignancies causing colonic stenosis were gastric cancer(n=4), cholangiocarcinoma(n=2), pancreatic cancer(n=2), lung cancer(n=2), uterine cancer(n=2), and ovarian cancer(n=1). The non-CRC group patients demonstrated a significantly lower technical success rate than those who received palliative stents for colonic stenosis for primary colorectal cancer(n=51)(69% vs 98%, p<0.01). In addition, the non-CRC group patients(n=13)also demonstrated a significantly lower technical success rate(69% vs 99%, pp<0.01)than those who received stents aiming to subsequently undergo a bridge to surgery. Nonetheless, colorectal stenting for extracolonic malignancies appears to be a minimally invasive treatment and could offer patients rapid relief. Thus, it could be an effective alternative to some palliative therapies.

[A Case of Local Recurrence with Negative FDG/PET Findings after a Total Proctocolectomy for Ulcerative Colitis Associated with Colon Cancer with Retroperitoneal Penetration].

We report the case of a 55-year-old man who successfully underwent resection of a recurrence of ulcerative colitis(UC)- associated colon cancer located in the pancreatic body and left kidney. The patient had undergone an emergency laparotomy (total proctocolectomy with stapled ileal-pouch anal anastomosis)for the treatment of a descending colon cancer with retroperitoneal penetration associated with UC at the age of 50 years. At that time, histological examinations revealed a mucinous carcinoma that was classified as Stage II colon cancer. Three years after the patient's initial operation, a CT scan revealed a small mass located between the pancreatic tail and the left kidney. However, the accumulation of FDG was not observed during a positron emission tomography(PET)examination, resulting in close observation. As the size of the tumor and the levels of serum carcinoembryonic antigen and carbohydrate antigen 19-9 gradually increased, recurrence was highly suspected. A distal pancreatectomy and left nephrectomy were performed. Pathological examination showed findings concurrent with a local recurrence of colon cancer. Special histological types, such as mucinous carcinoma, often occur in some colitic cancers. For the postoperative surveillance of patients with colitic cancer, it should be noted that the sensitivity of FDG/PET is lower for mucinous carcinoma of the colon than it is for more common colon cancers.