Endocrine Abstracts

Case history: We report an interesting case of a rare cause of hypopituitarism where our patient presented to the hospital with acute onset headache, vomiting, and feeling generally unwell.

Investigations/Results: On routine bloods, he was found to have hyponatremia. On further workup of hyponatremia, he had low morning cortisol which was confirmed as secondary adrenal insufficiency on dynamic function testing. He was also deficient in gonadotrophins alongside secondary hypothyroidism with low TSH, fT4, LH, FSH, and testosterone levels. He was started on appropriate hormone replacement therapy. Initial imaging was unremarkable including a normal brain CT and MRI showing pituitary within normal size limits to age but slightly bulky.

Clinical course/diagnosis: He re-presented to the hospital with disabling headaches, new worsening of vision, and 6th cranial nerve palsy. Given bulky appearing MRI On the previous scan, suspicion of apoplexy was raised but MRI Pituitary ruled this out. He continued to present to a local hospital with disabling headaches without any cause and was subsequently referred to Specialist Neurology Services at Tertiary care hospital. Repeat imaging on this occasion showed profusely enhanced smooth pachymeninges raising the suspicion of infective or inflammatory etiology which were ruled out on further testing. He was diagnosed to have idiopathic hypertrophic pachymeningitis (IHPM) after a thorough assessment.

Treatment: He was started on high-dose steroids with a good clinical response with improvement in his headaches, vision, cranial nerve palsies, and resolution of diplopia. He continues to show clinical improvement.

Conclusion: Hypopituitarism is known to occur due to various well-known causes, but rare causes of it described in literature if remain undiagnosed can cause significant clinical deterioration despite adequate hormonal replacement; therefore, it”s crucial to think out of the box and look for rare causes if the presentation is not classical to ensure appropriate maangement.

Points of discussion: Infective and inflammatory causes need to be excluded before the diagnosis of IHPM can be made. Suspect IHPM with the worsening clinical condition even after hormone replacement therapy for hypopituitarism. MRI brain is a valuable resource in addition to the biochemical profile performed for hormonal irregularities and should be used as a problem-solving tool. The initial imaging review could be within normal limits. Particular attention should be paid to the pachymeninges to identify any thickening or abnormal enhancement.