Cerebral Cavernous Malformations (CCMs) are vascular lesions involving brain capillaries. They may occur sporadically or be inherited as autosomal dominant character. Due to incomplete penetrance, CCMs incidence is underestimated and, overall sporadic cases, are often accidentally diagnosed. Rarely CCMs are linked to other pathological conditions. Here we present the first case in literature of a young woman affected by sporadic CCM, pituitary adenoma, Hashimoto thyroiditis and mental illness of unknown etiology. Symptoms’ analysis suggests that she may suffer of Hashimoto encephalopathy (HE), a condition that in very few cases develops together with Hashimoto thyroiditis. Genetic bases of HE are still unknown and symptomatology is very heterogeneous. This paper is a preliminary report of the case and is focused on complexity of clinical manifestations that makes the diagnosis uncertain. If our hypothesis will be confirmed by further analysis, our aim will be to clarify genetic causes of HE.