Introduction: Non-Hodgkin lymphoma (NHL) involving the hypothalamus and pituitary gland is rare. Central nervous system involvement by NHL may be either as a primary tumour or from systemic lymphoma. We report an interesting case of aggressive central nervous system (CNS) lymphoma presenting as pituitary macroadenoma.
Case report: A 67-year-old Caucasian woman presented with sudden onset of left eye ptosis and diplopia. Examination showed left third nerve palsy and visual field assessment revealed that she had bilateral inferior nasal defect. Pituitary function tests demonstrated hypocortisolaemia, secondary hypothyroidism and hypogonadotropic hypogonadism and she was commenced on Hydrocortisone and Levothyroxine. Magnetic resonance imaging (MRI) revealed pituitary macroadenoma measuring 14×12×11 mm with suprasellar extension. She underwent a CT angiogram that was normal. She had a history of diffuse large B-cell lymphoma in complete remission for more than 2 years. A repeat pituitary MRI within a month revealed that the lesion progressed to involve the hypothalamus and the optic tract. She underwent a biopsy of hypothalamic lesion that confirmed diffuse large B-cell CNS lymphoma. She was commenced on chemo-immunotherapy. Following second cycle of chemotherapy she developed transient diabetes insipidus (DI) requiring replacement with Desmopressin. Despite three cycles of chemotherapy, her intracranial disease progressed rapidly to involve the ventricles, posterior nasopharynx and possibly small nodes above and below the diaphragm. Subsequently the multidisciplinary Haematology team decided to discontinue active treatment and advised palliative care support.
Discussion: Sudden onset of ophthalmoplegia, headaches and DI in patients over 50 years should raise a suspicion of lymphoma or metastasis to the pituitary gland. NHL is a common lymphoma of the CNS. DI is the common presentation as the posterior lobe of pituitary receives blood supply directly from systemic circulation. In initial stages, MRI might not differentiate the aetiology. Hence biopsy is the gold standard to make accurate diagnosis.