Solitary splenic metastasis of pulmonary carcinoid: A rare case report and literature review

We herein report a rare case of solitary splenic metastasis of a pulmonary carcinoid, for which hand-assisted laparoscopic splenectomy was performed. A 73-year-old man was admitted to the Inoue Hospital (Fukuyama, Japan) in March 2015 with an abnormal shadow of the spleen. The patient had a history of right upper lobectomy with lymph node dissection for a pulmonary typical carcinoid (pT1N0M0 stage IA) 7 years earlier. Plain abdominal computed tomography (CT) revealed a low-density area in the spleen. Enhanced abdominal CT revealed a mass in the spleen measuring 3×3 cm. Blood tests and tumor marker analysis revealed no abnormalities. Abdominal magnetic resonance imaging revealed a mass that was low-intensity on T1- and high-intensity on T2-weighted images, and positron emission tomography revealed abnormal fluorodeoxyglucose accumulation in the mass. Hand-assisted laparoscopic splenectomy was performed for diagnosis and treatment. The resected specimen included a reddish-brown mass. On immunohistochemistry, the mass was positive for chromogranin A, synaptophysin and CD56, which was similar to the resected pulmonary carcinoid tumor; thus, splenic metastasis of pulmonary carcinoid was diagnosed. The postoperative course was uneventful and the patient is currently under observation and remains recurrence-free, with no adjuvant chemotherapy.