Endocrine Abstracts

A 21 year-old woman of Indian descent, but UK born and bread presented with a two-year history of intermittent headaches, hot flushes, polydipsia, nocturia and amenorrhoea. One year previously she had been diagnosed with primary hypothyroidism with a TSH of 7.3 and FT4 of 6.5. She was treated with thyroxine but remained amenorrhoeic.

Subsequent evaluation revealed TSH, LH, and FSH deficiency with evidence of cranial diabetes insipidus. An MRI scan of the pituitary gland showed an enlarged pituitary with a necrotic centre and pituitary stalk thickening. Subsequent trans-sphenoidal exploration revealed a sterile abscess, which was drained. PCR with m. tuberculosis specific amplimers from the abscess was positive. No acid-fast bacilli were isolated and culture remained sterile. Histological sections showed an avascular tissue containing a dense reticulin nework with lymphocytes and CD68 positive macrophages. Serum ANCA, ACE and ANA were all negative.

She was commenced on quadruple anti-tuberculous treatment, and full endocrine replacement. Post-operative pituitary testing revealed a normal ACTH reserve, but persistent TSH, LH and FSH deficiency and diabetes insipidus. Repeat MRI after three months, showed residual pituitary enlargement with evidence of central necrosis and stalk thickening.

Tuberculous hypophisitis is an unusual cause of hypopituitarism in the UK, and as in this case, may occur in the absence of pulmonary disease. The symptoms may have an insidious onset, and it should form part of the differential diagnosis of cystic pituitary masses.