Acquired spontaneous periodic hypothermia and pancytopenia secondary to hypothalamic compression from a large skull base meningioma.

A 69-year-old woman with a recurrent skull-base meningioma developed recurrent hypothermia during rehabilitation, initially misattributed to infection. Episodes followed a circadian pattern and were associated with delirium, pancytopenia, and signs of central endocrine dysfunction. MRI showed a large meningioma compressing the hypothalamus with an intact corpus callosum. Infection and adrenal insufficiency were excluded. Hypothermia resolved with external warming, and pancytopenia normalized spontaneously. Subclinical hypothyroidism and central hypogonadism were noted, consistent with hypothalamic-pituitary axis involvement. These findings supported a diagnosis of acquired spontaneous periodic hypothermia (SPH) due to hypothalamic compression. This case illustrates that early recognition of SPH in patients with skull-base tumors can prevent misdiagnosis and guide appropriate supportive care and monitoring.