Background <p>Isolated splenic metastases from colorectal cancer (CRC) are an extremely rare clinical entity with unclear clinical characteristics. The purpose of this study was to clarify the prognostic factors, therapeutic outcomes, diagnostic methods, and clinical patterns related to this uncommon metastatic entity.</p> Methods <p>We describe a novel instance of metachronous isolated splenic metastasis treated at our institution. Additionally, from the database’s creation to December 2025, we performed a comprehensive literature search in PubMed, Web of Science, and the Cochrane Library, finding 36 previously documented cases. Descriptive statistics were used to examine clinical and demographic features, diagnostic techniques, treatment plans, and results.</p> Results <p>Our patient, a 56-year-old man, developed a solitary splenic metastasis 34 months after undergoing laparoscopic left hemicolectomy for descending colon adenocarcinoma. The splenic metastasis was subsequently managed with laparoscopic splenectomy. A thorough analysis of 37 cases, including our own, showed clear clinical patterns: 86.5% (32/37) of cases presented with metachronous disease, with a median interval of 24 months; left-sided primary tumors (sigmoid colon, rectum, descending colon, and splenic flexure) predominated (29/37, 78.4%); splenectomy was associated with an 89.3% disease-free survival rate among patients with available follow-up, with metachronous cases showing particularly favorable outcomes (95.8%).</p> Conclusion <p>This comprehensive research highlights the significance of long-term surveillance in CRC patients and indicates that complete surgical excision of isolated splenic metastases may be associated with favorable outcomes, especially in metachronous presentations.</p>