Endocrine Abstracts

Fifty year-old year old gentleman presented unwell whilst on holiday with headache and vomiting. He also reported a clear fluid trickling down his nose. On examination he was pyrexial, photophobic and had demonstrable neck stiffness. Lumbar puncture and a subsequent culture confirmed streptococcal meningitis which responded to antibiotics.

His CT scan head suggested a pituitary mass and a subsequent MRI revealed an unusual massive pituitary tumor extending into the sphenoid sinus, the clivus and the cavernous sinus with a necrotic centre communicating with the supra sellar cisterns.

Pituitary screening bloods was indicative of a TSH oma with fT4 32.4 pmol/l (11–22.7), fT3 8.2 pmol/l (0.9–2.8) and TSH 2.4 mU/l (0.5–5.50). Prolactin was 2820 mU/l (45–375), testosterone 9.9 nmol/l (10–20) and cortisol 391 nmol/l. Synacthen test was normal.

He had a transphenoidal biopsy and the CSF leak was repaired. Biopsy confirmed a pituitary adenoma and on immunochemistry it showed reactivity with TSH and prolactin.

Alpha subunit was elevated at 24 μ/l confirming the diagnosis of a TSH oma.

The tumor was deemed unsuitable for debulking surgery or medical treatment and he had radical radiotherapy.

Although asymptomatic after radiotherapy he had two further admissions with headache. First one with pneumoencephalus after his GP gave him intra nasal steroids for blocked sinuses. It was thought that the intra nasal spray had led to pressure changes causing the pneumo encephalus.

Second admission was with recurrent CSF leak and meningitis.This was treated with antibiotics and he had a further leak repair done.

At a recent follow up MRI demonstrated 33% reduction in the tumor size.

Discussion: TSH omas are rare forming less than 1% of pituitary adenomas and can be invasive. To our knowledge this is the first reported case of recurrent meningitis secondary to an invasive TSH oma.