Isolated splenic metastasis from colon cancer--case report and literature review

Solitary splenic metastases are very rare and sporadic. There are several explanations for this low incidence of splenic metastasis including anatomical, histological and immunological features of the spleen. In this paper we present a case of 70-year-old man with no history of previous diseases who was first operated under the diagnosis of acute abdomen revealing perforated colon tumor of splenic flexure with no metastases at that time. Left hemicolectomy was performed followed by postoperative complications demanding a subtotal colectomy and ileostomy. Primary tumor was classified as Dukes (Astler-Coller)-C2, T4NIMO. Patient was referred to oncologist and received chemotherapy (5FU, Leucovorin). 5 months later continuity of the gut was performed by ileosygmoanastomosis. 2 years after first surgical procedure, a CT scan and abdominal ultrasound, followed by needle biopsy, showed isolated metastasis in spleen, so splenectomy was performed. Pathological findings revealed sharply bordered, partially necrotic tumor inside of spleen tissue, spreading to, but not reaching splenic hilum. Histology showed low to medium differentiated adenocarcinoma tissue with desmoplastic stromal reaction. There were no protrusions of tumor cells through spleen surface. In splenic hilum 4 tumor free lymph nodes were harvested. No additional chemotherapy was conducted. The latest follow up, a year after diagnosis of metastasis showed no signs of cancer disease. Review of the literature showed that long term survival and prognosis of isolated splenic colorectal metastasis after splenectomy are rather optimistic, although these are the cases of distant metastasis. Due to small number of cases reported in literature, definitive conclusions and/or guidelines for the treatment of isolated splenic metastasis cannot be given, but splenectomy and chemotherapy are preferable in the treatment, promising long term survival at least for metachronous metastasis.