Stereotactic Radiosurgery for Carcinoid Brain Metastasis: A Case Report

Abstract

Carcinoid brain metastases are extremely rare and are associated with a poor prognosis. Treatment options are variable, ranging from surgery, radiation, or chemotherapy alone or combined. We report on a case of rectal carcinoid metastatic to the cerebellum and review chemotherapeutic regimens for carcinoid tumor treatment, focusing on the potential role of temozolomide or stereotactic radiosurgery.

Keywords: brain metastasis; carcinoid; chemotherapy; rectal carcinoid; stereotactic radiosurgery; temozolamide.

Figure 1. MRI of cerebellar mass

(A) Axial T1 post-contrast image of the brain demonstrates an avidly enhancing cerebellar mass arising from the vermis. (B) Axial T2 MR image shows surrounding vasogenic edema and effacement of cerebellar sulci. (C) Post-surgical axial T1 post-contrast image of the brain demonstrates a surgical cavity with no evidence of residual neoplasm.

Figure 2. Microscopic findings of metastatic neuroendocrine tumor

(A) Cellular organoid architecture with nests, cords, and glands in the background of rich vascular network, H&E stain, 100X. (B) Small to median tumor cells with eosinophilic and finely granular cytoplasm, uniform nuclei and finely stippled chromatin, H&E stain, 400X. (C) Immunostain for syneptophysin demonstrating diffuse cytoplasmic positivity in tumor cells, 400X. (D) CD56 stain showing strong cell membrane reactivity in tumor cells, 400X.