The surgical treatment of acute and severe diversion colitis mimicking ulcerative colitis: a case report

Abstract Background Diversion colitis (DC) is characterized by nonspecific inflammation in the remaining colon or rectum, and loss of the fecal stream plays a major role in the disease’s development. Although the majority of patients are asymptomatic, medical and/or surgical treatment is required for those who are symptomatic. There is a particular interest on how to manage patients with acute and severe clinical presentations, but the pathogenesis is not fully understood. We report the rare case of a man with acute and severe DC mimicking ulcerative colitis (UC) with extra-intestinal manifestations that was successfully managed with surgical treatment. Case presentation A 68-year-old man with a history of laparoscopic intersphincteric resection of the rectum with diverting loop ileostomy for lower rectal cancer suffered from anastomotic stenosis requiring repeated endoscopic dilatation. His loop stoma was not reversed because these treatments were unsuccessful. He denied having a history of inflammatory bowel disease. Twelve years postoperatively, he developed a perineal abscess requiring drainage. Subsequently, he developed a high-grade fever, bloody discharge per anus, and skin ulcers in the right ankle and around the stoma. Because culture tests were negative for bacteria, it was deemed that his acute illness reflected an inflammatory response rather than an infectious disease. Colonoscopy revealed anastomotic stenosis, a colonic fistula, and mucosa that hemorrhaged easily, with lacerations. A pathological examination with biopsy revealed inflammatory infiltration without malignancy. After reviewing the patient’s clinical episodes and discussing the case with physicians in multiple specialties, we performed total colectomy with end ileostomy in accordance with the abdominoperineal resection. The postoperative course was uneventful. A resected specimen showed atrophic mucosa with the disappearance of haustra in the distal colon, as well as edematous and dilated mucosa in the proximal colon. The pathological diagnosis was suggestive of UC, including erosion and ulceration in edematous wall, crypt abscess, and inflammatory infiltration into the mucosa. The skin ulcers in the right ankle and around the stoma healed over time. Conclusions DC can eventuate in a long-term period after fecal diversion surgery, possibly with extra-intestinal manifestations mimicking UC. Surgical treatment seems feasible for patients with acute and severe DC

Longitudinal monitoring of KRAS-mutated circulating tumor DNA enables the prediction of prognosis and therapeutic responses in patients with pancreatic cancer.

BACKGROUND:Liquid biopsies enable the detection of circulating tumor DNA (ctDNA). However, the clinical significance of KRAS-mutated ctDNA for pancreatic cancer has been inconsistent with respect to its prognostic and predictive potential. METHODS AND FINDINGS:A total of 422 blood samples were collected from 78 patients undergoing treatments for localized and metastatic pancreatic ductal adenocarcinoma. KRAS mutation in tissues and KRAS ctDNA levels in plasma were determined by RASKET and droplet digital polymerase chain reaction. Longitudinal monitoring of KRAS ctDNA was performed to assess its significance for predicting recurrence and prognosis and for evaluating therapeutic responses to chemotherapy compared with carbohydrate antigen 19-9 (CA19-9). In 67 tumor tissues, discrepancies in point mutations of KRAS were rarely observed among individual patients, implying that one targeted point mutation of KRAS can be determined in tumor tissues prior to longitudinal blood monitoring. One-time blood assessment of KRAS-mutated ctDNA before surgery or chemotherapy was not clearly associated with recurrence and prognosis. Sequential blood monitoring was performed in 39 patients who underwent surgery for potentially resectable tumors. Increased CA19-9 levels were significantly associated with recurrence, but not prognosis (P<0.001, P = 1.0, respectively), whereas emergence of KRAS ctDNA was significantly associated with prognosis (P<0.001) regardless of recurrence. Furthermore, in 39 patients who did not undergo surgery, detection of KRAS ctDNA was a predictive factor for prognosis (P = 0.005). Multivariate analysis revealed that detection of KRAS ctDNA was the only independent prognostic factor regardless of tumor resection (hazard ratios = 54.5 for patients who underwent surgery and 10.1 for patients who did not undergo surgery; P<0.001 for both). Patients without emergence of KRAS ctDNA within 1 year after surgery showed significantly better prognosis irrespective of recurrence (P<0.001). No detection or disappearance of KRAS ctDNA within 6 months of treatment was significantly correlated with therapeutic responses to first-line chemotherapy (P<0.001). Changes in KRAS status provided critical information for the prediction of therapeutic responses. CONCLUSIONS:Our study showed for the first time that detection of KRAS ctDNA levels within a short period enables the prediction of prognosis and therapeutic responses in patients with pancreatic cancer