Single brain metastases of carcinoid tumors.

Carcinoid tumors are one among the most uncommon source of metastatic lesion to the brain. Four cases of single brain metastases from carcinoid tumors operated upon and verified by both histology and immunohistochemical staining are reported. The site of the primary carcinoid tumor was the lung in two cases, ileum in one and the left colon in another. The location of the brain metastasis was supratentorial in two cases and cerebellar in two. A high vascular tumor with large blood channels was found at surgery. Immunohistochemical studies showed in all four cases positive staining for synaptophysin, neuron-specific enolase, chromogranine and cytocheratine and negative staining for S-100 and HMB-45. The postoperative survival time ranged from 5 to 18 months. The epidemiological, surgical and pathological features of brain metastases from carcinoid tumors are also discussed from the analysis of 44 well-documented cases reported in the literature.