Late Lyme disease masking a non‐functioning adenoma of the anterior lobe of the pituitary gland

Lyme disease is a multisystem disorder caused by the tick-borne spirochete Borrelia (B) burgdorferi. Symptoms of chronic central nervous system involvement may comprise nonspecific signs such as affection of memory and mood (Logigian et al., 1990). Pituitary tumours may also cause different modes of clinical presentation. Hyperprolactinemia and hypogonadism as well as nonspecific secondary sequelae have been observed (Stoffel-Wagner et al., 1997). We describe a patient with late Lyme borreliosis (LLB) and adenoma of the pituitary gland, with emphasis on establishing the proper diagnosis.