Colosplenic fistula diagnosis and management: a case series and review of literature.

BACKGROUND: A colosplenic fistula (CsF) is an extremely rare complication. Its diagnosis and management remain poorly understood, owing to its infrequent incidence. Our objective was to systematically review the etiology, clinical features, diagnosis, management, and prognosis to help clinicians gain a better understanding of this unusual complication and provide aid if it is to be encountered. METHODS: A systematic review of studies reporting CsF diagnosis in Ovid MEDLINE, Ovid EMBASE, Scopus, Web of Science, and Wiley Cochrane Library from 1946 to June 2022. Additionally, a retrospective review of four cases at our institution were included. Cases were evaluated for patient characteristics (age, sex, and comorbidities), CsF characteristics including causes, symptoms at presentation, diagnosis approach, management approach, pathology findings, intraoperative complications, postoperative complications, 30-day mortality, and prognosis were collected. RESULTS: Thirty patients with CsFs were analyzed, including four cases at our institution and 26 single-case reports. Most of the patients were male (70%), with a median age of 56 years. The most common etiologies were colonic lymphoma (30%) and colorectal carcinoma (17%). Computed tomography (CT) was commonly used for diagnosis (90%). Approximately 87% of patients underwent a surgical intervention, most commonly segmental resection (81%) of the affected colon and splenectomy (77%). Nineteen patients were initially managed surgically, and 12 patients were initially managed nonoperatively. However, 11 of the nonoperative patients ultimately required surgery due to unresolved symptoms. The rate of postoperative complications was (17%). Symptoms resolved with surgical intervention in 25 (83%) patients. Only one patient (3%) had had postoperative mortality. CONCLUSIONS: Our review of 30 cases worldwide is the largest in literature. CsFs are predominantly complications of neoplastic processes. CsF may be successfully and safely treated with splenectomy and resection of the affected colon, with a low rate of postoperative complications.

L1CAM is required for early dissemination of fallopian tube carcinoma precursors to the ovary.

Most ovarian high-grade serous carcinomas (HGSC) arise from Serous Tubal Intraepithelial Carcinoma (STIC) lesions in the distal end of the fallopian tube (FT). Formation of STIC lesions from FT secretory cells leads to seeding of the ovarian surface, with rapid tumor dissemination to other abdominal structures thereafter. It remains unclear how nascent malignant cells leave the FT to colonize the ovary. This report provides evidence that the L1 cell adhesion molecule (L1CAM) contributes to the ability of transformed FT secretory cells (FTSEC) to detach from the tube, survive under anchorage-independent conditions, and seed the ovarian surface. L1CAM was highly expressed on the apical cells of STIC lesions and contributed to ovarian colonization by upregulating integrins and fibronectin in malignant cells and activating the AKT and ERK pathways. These changes increased cell survival under ultra-low attachment conditions that mimic transit from the FT to the ovary. To study dissemination to the ovary, we developed a tumor-ovary co-culture model. We showed that L1CAM expression was important for FT cells to invade the ovary as a cohesive group. Our results indicate that in the early stages of HGSC development, transformed FTSECs disseminate from the FT to the ovary in a L1CAM-dependent manner.