Lymphocytic Hypophysitis (LH) is the most common variant of primary hypophysitis, which is a rare condition itself. LH is a rare inflammatory/autoimmune disease of the pituitary gland and the stalk. The authors present this case given its rarity, and difficulty to diagnose, and atypical presentation. The case refers to a 36-years old female, 2 pregnancies, 2 childbirths, who at the 10th gestational week of the second pregnancy complained of frontal headaches with decreased visual acuity on the left eye. The patient went to the emergency department for clinical evaluation, having been admitted and observed by neurology and ophthalmology departments for five days. No radiological tests were carried given the situation, having been medicated with paracetamol, with no diagnosis. The patient was discharged with no headache complaints, although a slight visual impairment. A year after childbirth, she starts complaining of frontal headaches again, which irradiate to the left orbit, and slow pupil reflexes, having been observed by the department of ophthalmology that asked for a brain and orbit MRI that showed a suspicion of Rathke pouch cyst and possible lesion to the optic chiasm. After discussing with a multidisciplinary team, it was decided to proceed with a left pterional approach to puncture the cyst. The tissue removed was sent to pathology for histological study. The resulting diagnosis is compatible with LH, namely fibrous connective tissue with glandular structures from the adenohypophysis, with a mild to moderate lymphocytic inflammatory infiltrate, with no signs of neoplastic development.
