Differential diagnosis
There are usually no differential diagnoses for a colloid cyst. In atypical cases it is worth considering other masses which arise in the region of the foramen of Monro, including:
calcified or hyperdense meningioma
giant cell astrocytoma
pilocytic astrocytoma
blood in the region of foramen of Monro
For a more complete list please refer to masses in the region of the foramen of Monro.