A 44-year-old man with a history of Whipple's disease 8 years ago presented
with recurrent grand mal seizures and signs of hypopituitarism on physical
examination. Magnetic resonance imaging of the brain revealed a hypothalam
ic lesion of 1 cm diameter in the region of the rostral infundibulum, Hypop
ituitarism was confirmed by low levels of serum cortisol, free testosterone
and free thyroxine without an elevated TSH. Whipple encephalitis with hypo
thalamic involvement was suggested and verified by positive polymerase chai
n reaction (PCR) for Tropheryma whippelii in the cerebrospinal fluid. PCR f
or T. whippelii has become an important diagnostic tool for establishing th
e diagnosis of Whipple's disease especially in patients with unusual presen
tations and if the diagnosis cannot be confirmed histologically, Whipple's
disease should be included in the differential diagnosis in hypopituitarism
caused by infectious disease.