Nonneoplastic Mass Lesions of the Hypothalamus

Nonneoplastic mass lesions of the hypothalamus are rare but are composed of a variety of pathologies. These can be broken down into cystic lesions, such as epidermoid, dermoid, arachnoid, colloid, and Rathke’s cleft cysts; vascular lesions, such as cavernomas and hypothalamic hamartomas; inflammatory, including hypothalamitis, syphilitic gummas, tuberculomas, toxoplasmosis-related lesions; and inflammatory lesions, including multiple sclerosis, sarcoidosis, and granulomatosis with polyangiitis. Many of these lesions do not present as isolated entities but as part of a larger overarching diagnosis, thus providing clues into the nature of the hypothalamic lesion. As with other space-occupying lesions in the hypothalamic region, the common symptoms include visual disturbances and endocrine problems, with the most common symptom being diabetes insipidus. Nonneoplastic lesions are generally associated with a more indolent course and a wider range of treatment options, from surgical excision to radiotherapy and medical management like antibiotics and anti-inflammatory agents. In some cases, spontaneous resolution can also be a welcome outcome.