Metastatic prostate adenocarcinoma to intradural foramen magnum

Intradural metastatic tumors are rarely reported in foramen magnum (FM), including cases of melanoma, pituitary carcinoma, thyroid carcinoma, and prostate carcinoma metastases. We report a 68-year-old male who presented with right-sided headache, progressive swallowing difficulty requiring gastrostomy tube and hoarseness over the course of 1 year. Images revealed a heterogeneous, contrast-enhancing lesion in the FM that compressed the anterior aspect of the medulla and upper spinal cord. Although metastatic tumor was considered in differential diagnosis, presumptive diagnosis was FM meningioma due to lack of bone destruction or sclerosis on CT and T2W isointense and T1W hypointense appearance on MRI. The patient underwent gross total resection via right far-lateral transcondylar approach. Histopathological examination revealed prostate carcinoma metastasis. To the best of our knowledge this is the second case report of an intradural prostate carcinoma metastasis in the FM.