Isolated splenic metastases from colorectal carcinoma and pancreatic neuroendocrine tumor: a report of two rare cases.

Background: Splenic metastases usually historically signal pre-terminal malignancy, arising amid widespread tumor dissemination and most often discovered at autopsy. Isolated splenic metastases without disseminated disease are exceedingly rare, with only a limited number of cases reported in the literature. Recognizing these presentations is important as isolated splenic involvement may be amenable to definitive management in contrast to the poor prognosis associated with splenic spread. Case Description: In this report, we present two patients with isolated splenic metastases. The first is an 83-year-old patient with splenic metastasis secondary to colorectal cancer. The second is a 29-year-old patient with splenic metastasis secondary to a pancreatic neuroendocrine tumor (PNET), which, to our knowledge, may represent a novel incidence. Neither patient had evidence of disseminated disease at presentation. In this case report, we review the clinical presentation, diagnostic workup, and management of both cases, each of which demonstrate a favorable short-term outcome. Conclusions: These cases taken together show that isolated splenic disease, when identified in the absence of widespread metastasis, can be operatively and chemically managed with favorable short-term results. The PNET patient in particular broadens the recognized spectrum of primary tumor locations that can metastasize to the spleen in isolation. Further reports and longer follow-ups, however, are needed to identify the optimal management and longer-term prognoses.