Endocrine Abstracts

A 74-year-old male presented with acute onset retro-orbital pain and nausea. He also complained of blurred vision and inability to open his left eye. There was no family history and the only past medical history was hypercholesterolemia treated with simvastatin. Clinical examination revealed a complete left ptosis, the left pupil was dilated with sluggish reaction to light and there was impaired adduction of the left eye. Visual fields and visual acuity were normal. Examination was otherwise normal. Investigations revealed Na 131 mmol/l, other electrolytes normal. Endocrine investigations revealed serum testosterone 5.3 nmol/l, prolactin 701 mU/l, LH 1.1 IU/l, FSH 4.4 IU/l, free T4 10.03 pmol/l TSH 1.03 mIU/l. Short synacthen test; baseline cortisol 129 nmol/l, 60 min cortisol 921 nmol/l. MRI of the pituitary revealed a mass arising within the pituitary fossa extending into the left cavernous sinus and impinging on the inferior surface of the optic chiasm consistent with a pituitary adenoma. There was no evidence of apoplexy. The initial diagnosis was a non-functioning pituitary macroadenoma. The patient underwent transphenoidal resection, operative findings were consistent with a pituitary adenoma. Subsequent histology showed a neoplasm composed of diffuse sheets of malignant lymphoid cells, consistent with a high grade B-cell lymphoma. In addition there was a fragment of adenoma strongly immunoreactive for FSH which was partly necrotic, indicating a gonadatroph adenoma with a degree of apoplexy. Examination and imaging did not reveal evidence of lymphoma elsewhere.

In this case the main tumour was a primary pituitary lymphoma (PPL). However, we suspect that apoplexy of the pituitary adenoma caused the acute headache and contributed to the third nerve palsy. PPL is a rare condition which may present with features consistent with a pituitary adenoma; headache, cranial nerve dysfunction, and endocrinopathy. The only definitive way to confirm the diagnosis of PPL is with histology.