Case Report: A Rare Case of Esophagogastric Junctional Squamous Cell Carcinoma After the Successful Treatment of Neuroendocrine Carcinoma: Clonal Tumor Evolution Revealed by Genetic Analysis.

Neuroendocrine carcinoma (NEC) of the esophagogastric junction (EGJ) is a rare disease with no established treatments. Herein, we describe a case of recurrent squamous cell carcinoma (SCC) after achieving complete response to chemotherapy against NEC of the EGJ. A 67-year-old man was referred to our hospital because of epigastric discomfort. Computed tomography imaging and esophagogastroduodenoscopy revealed ulcerated tumors at the EGJ. Endoscopic biopsy revealed small tumor cells with a high nuclear/cytoplasmic ratio, suggesting small-cell NEC. Immunohistochemistry (IHC) analysis showed tumor cells with an MIB-1 index of 80%. The patient achieved complete response after 10 cycles of chemotherapy. Follow-up endoscopic examination revealed small red-colored mucosal lesions in the center of the cicatrized primary lesion. Re-biopsy detected cancer cells harboring large eosinophilic cytoplasm with keratinization and no evidence of NEC components. IHC of the cells were cytokeratin 5/6-positive and p53-negative. The tumor persisted without evidence of metastases after chemoradiotherapy, and total gastrectomy with lymph node dissection was performed. Pathological assessment of the resected specimens revealed SCC, without evidence of NEC. The patient survived without a recurrence for >3 years after the initial presentation. Somatic mutation profiles of the primary NEC and recurrent SCC were analyzed by targeted amplicon sequencing covering common cancer-related mutations. Both tumors possessed TP53 Q192X mutation, whereas SMAD4 S517T was found only in SCC, suggesting that both tumor components originated from a founder clone with a stop-gain mutation in TP53. The somatic mutation profile of the tumors indicated that that loss of heterozygosity (LOH) at the TP53 gene might have occurred during the differentiation of the founder clone into NEC, while a SMAD4 mutation might have contributed to SCC development, indicating branching and subclonal evolution from common founder clone to both NEC and SCC. The mutation assessments provided valuable information to better understand the clonal evolution of metachronous cancers.

Effectiveness of Intraoperative Indocyanine Green Fluorescence-Navigated Surgery for Superior Mesenteric Vein Thrombosis that Developed During Treatment for Intravascular Lymphoma: A Case Report.

BACKGROUND Superior mesenteric vein thrombosis (SMVT) is a relatively rare form of acute abdominal disease; less than 0.1% of laparotomy surgeries are performed for SMVT. In the presence of severe intestinal ischemia or necrosis caused by SMVT, immediate surgical intervention is required. Macroscopic diagnosis of intestinal viability is sometimes difficult; its over-resection may carry the risk of short bowel syndrome. A near-infrared fluorescence imaging system with indocyanine green (ICG) has recently been developed for intraoperative, real-time evaluation of intestinal perfusion. This is the first report on the use of ICG fluorescence imaging during surgery for intestinal ischemia caused by venous thrombosis. CASE REPORT A 70-year-old man presented with a general feeling of weariness. On examination, he was diagnosed with intravascular large B cell lymphoma. R-CHOP therapy was initiated. On day 3 of initial R-CHOP therapy, the patient experienced sudden severe abdominal pain while in the hospital. Contrast-enhanced computed tomography revealed SMVT and loss of contrast effect in the small intestine. We diagnosed small bowel necrosis caused by SMVT, and exploratory laparotomy was performed, which revealed a continuous ischemia of 150 cm. Intraoperative ICG fluorescence imaging was utilized, and the color boundary was consistent with the ischemic area detected by visualization. The necrotic small intestine was excised and anastomosed. The patient was transferred to the hematology department on postoperative day 10 with no severe complications such as anastomotic leakage or re-thrombosis, and re-embolization was not observed 6 months later. CONCLUSIONS Venous thrombosis should be listed as a differential diagnosis when acute abdominal disease presents during chemotherapy for malignant lymphoma. ICG fluorescence imaging may be useful in the evaluation of intestinal blood flow for venous thrombosis.

A Benign Appendiceal-Colonic Fistula, Diagnosed and Managed Laparoscopically: A Case Report.

BACKGROUND Treatment methods for appendiceal-colonic fistulas differ greatly depending on whether lesions are benign or malignant. If the tumor is malignant, appendectomy with lymph node resection (ileocecal resection or right hemicolectomy) should be performed. There is no consensus on the method of surgery for organs infiltrated by appendiceal cancer. Furthermore, there are no reported laparoscopic cases that could be prevented from over-surgery by laparoscopy examination or rapid intraoperative pathological examination. CASE REPORT A 76-year-old man presented with positive fecal occult blood. Lower endoscopy revealed a 10-mm tumor in the rectosigmoid colon accompanied by white moss. A biopsy showed inflammatory granulation and no malignancy. Fluorodeoxyglucose-positron emission tomography showed highly increased accumulation at the tip of the appendix, and the standardized uptake value max was 7.3. We suspected a benign lesion rather than appendiceal cancer with infiltration into the rectosigmoid colon; therefore, we performed laparoscopic appendectomy and wedge-shaped resection of the rectum of the sigmoid colon. An intraoperative rapid pathological examination showed no appearance of malignancy; therefore, additional resection was omitted, and an ileostomy was created in the right lower quadrant. A permanent pathological examination showed complicated appendicitis, with no appearance of malignancy. The ileostomy was closed on postoperative day 25, and the patient was discharged on postoperative day 32. CONCLUSIONS In cases where there is difficulty in identifying whether the appendiceal-colonic fistula lesion is benign or malignant, laparoscopy and intraoperative rapid pathological examination may be useful in avoiding excessive treatment.

Difficult Diagnosis and Surgical Procedure for Scirrhous Gastric Cancer Complicated by Upside-Down Stomach: A Case Report.

BACKGROUND The upper stomach can be involved in 1 type of esophageal hiatal hernia in which the degree of stomach insertion is considerable and accompanied by a twist in the shaft of the stomach. The diagnostic accuracy of upper endoscopy or barium meal examination decreases in patients with upside-down stomach, thus making diagnosis of stomach lesions very difficult. No previous reports have described scirrhous gastric cancer in a patient with upside-down stomach. CASE REPORT An 85-year-old woman presented with loss of appetite and vomiting after eating oxalic acid-containing food 2 months previously. Computed tomography revealed an upside-down stomach, and upper endoscopy revealed loss of distensibility and superficial gastritis of the entire stomach. Upside-down stomach was diagnosed; accordingly, laparoscopic hernia repair was planned. Laparoscopic exploration revealed retention of serous fluid (i.e., ascites) containing gastric carcinoma cells (pathologically identified intraoperatively) and induration of the entire stomach. After converting to laparotomy, induration of the stomach was confirmed, continuing to the adjacent 4 cm of the distal esophagus. The patient was diagnosed with scirrhous gastric cancer. Esophageal hiatus hernia repair was performed due to the patient's age and the risks associated with esophagojejunostomy. Preoperative complaints of symptoms disappeared. The patient was transferred to the medical hospital on postoperative day 52 with no complications. CONCLUSIONS Specific symptoms of gastric cancer can mimic those of esophageal hiatal hernia in patients with hernia. In cases of upside-down stomach with loss of distensibility and increased wall thickness, physicians should be aware of the possibility of scirrhous gastric cancer.

[A case of advanced gastric cancer responding to S-1/paclitaxel/lentinan as neoadjuvant chemoimmunotherapy].

A 71-year-old man suffering from epigastric discomfort and dizziness was admitted to our hospital and diagnosed with advanced gastric cancer with bulky lymph node metastases and liver metastasis. We thought a complete resection would be difficult, so he was treated with neo-adjuvant immunochemotherapy in combination with S-1 80 mg/m2 (2 weeks administration and 2-week rest), paclitaxel (PTX) 50 mg/m2 (day 1, 8, 15) and Lentinan (LNT) 2 mg/body (day 1, 8, 15). After 5 courses of this treatment, swollen lymph nodes decreased in size and the metastatic liver tumor disappeared. Total gastrectomy with lymph node dissection was performed. The histological diagnosis was pT2 pN0, Stage I B. Histological effects of primary tumor and lymphnodes were judged to be grade 2 and grade 3, respectively. We considered that the combination of S-1, PTX and LNT can be effective and safe for advanced gastric cancer.