Google search to the rescue! this was a new diagnosis for me
Correct term: hamartoma of tuber cinereum
non-neoplastic congenital heterotopias of grey matter located in the region of the tuber cinereum of the hypothalamus or maxillary bodies. Macroscopically they are nodules of variable size, from a few mm in diameter to 1-2 cm in diameter, sessile or pedunculated, attached to the outer surface of the tuber cinereum and lying in the interpeduncular cistern between the infundibular stalk anteriorly and the mamillary body posteriorly. Histologically they are characterized by an abnormal heterotopic collection of large and small neurons, astrocytes and oligodendroglial cells, without any potential for malignancy.
Clinically they may either be asymptomatic, or produce precocious puberty and/or a specific type of seizure called gelastic ("laughing attacks"), of the partial complex type, associated sometimes with psychiatric disturbances and cognitive impairment. On CT, hypothalamic hamartomas appear as rounded, well defined masses, isodense with brain tissue, lying in the suprasellar cistern. No enhancement is usually seen after contrast injection.
Surgical Treatment is possible if seizures experienced---see the articles in the links below.