Pathognomonic intracranial calcification.

Non-pathological intracranial calcification is common in the pineal, choroid plexus and in the falx cerebri and is readily recognizable by their positions. Large calcifications can occur in a pinealoma, in the choroid plexus in tuberous sclerosis and neurofibromatosis and at the falx with a meningioma. Healed granulomas, especially tuberculosis and parasites, can produce small single or scattered nodules of intra-parenchymal calcification. Calcification in the globus pallidus is a not uncommon occurrence in the elderly and usually non-pathological. Tumours, aneurysms and subdural haematomas can also calcify, have characteristic sites and are linear or curvilinear while periventricular calcification occurs following intra-uterine infections with toxoplasmosis and cytomegalic inclusion disease. Congenital malformations such as lipoma of the corpus callosum and Sturge-Weber syndrome are also localized and have characteristic appearances. However, bilateral symmetrical calcification ofthe caudate and dentate nuclei and associated calcification in the corona radiata is characteristic of hypoparathyroidism and pseudohypoparathyroidism. This patient was known to have hypoparathyroidism for the last 30 years.