Pituitary Pseudo-Adenoma From Cerebrospinal Fluid Leak in Marfan Syndrome

Document Type

Conference Proceeding

Publication Date

4-2023

Abstract

Introduction

Spontaneous intracranial hypotension (SIH) due to cerebrospinal fluid leaks are a rare clinical entity with an estimated annual incidence of 4-5 cases per 100,000, with a female predominance. Of those cases, 42% are caused by spinal meningeal diverticula, which have been associated with connective tissue disorders such as Marfan syndrome. Ectasia of the dura has been found to occur in up to 90% of Marfan patients. Typical symptoms of IH include postural headache, nausea, vomiting, tinnitus and dizziness. Pituitary enlargement has been reported on imaging findings and hypothesized to be caused by compensatory engorgement of the epidural venous plexus. With said enlargement having the potential to mimic a pituitary macroadenoma, increased awareness may avoid misdiagnosis and unnecessary procedures.

Case Presentation

We present a case of a 25 year old female with Marfan syndrome due to fibrillin gene mutation presenting with orthostatic headache, dizziness, tinnitus, fatigue, nausea and bitemporal hemianopsia that started 10 months prior without a precipitating event. The patient was initially assessed at an outside hospital and was diagnosed with a pituitary macroadenoma measuring 1.2cm x 0.9 cm and slightly remodeled optic chiasm. Brain MRI at that time also demonstrated tonsillar ectopia, dural venous sinus distention and mild pachymeningeal enhancement, concerning for IH. The patient was later transferred to our institution for further evaluation. A repeat brain MRI confirmed findings consistent with IH. Dedicated pituitary MRI showed similar enlargement of the adenohypophysis with normal neural hypophysis without signs of intraglandular nodule, further supporting the diagnosis. As the patient reported nausea, fatigue and orthostatic lightheadedness, an endocrinology evaluation was performed. Pituitary hormone levels including ACTH, FSH, LH, TSH, GH and prolactin were normal. MRI spine demonstrated thoracic and lumbar meningeal diverticula and significant dural sac ectasia at the L4-S2 level. Myelogram confirmed numerous lumbar spine diverticula with noted CSF leak at the right L5 and S1 nerve roots. The patient was recommended bed rest and received an epidural blood patch at the level of the leak with significant improvement in symptoms.

Discussion

Spontaneous intracranial hypotension is a rare clinical entity that has been associated with connective tissue disorders including Marfan syndrome. Dural weakness causing meningeal diverticula is believed to predispose patients to spontaneous CSF leaks. Imaging phenomena of IH include subdural fluid collections, diffuse pachymeningeal enhancement, brainstem descent with cerebellar tonsillar herniations as well as pituitary enlargement, which is believed to be secondary to compensatory venous engorgement and may be present in up to 57% of IH cases. The treatment of IH involves bed rest, high caffeine intake and epidural blood patches and has proven to reverse or diminish pituitary enlargement. Symptoms of IH can overlap with symptoms of adenohypophysis dysfunction and adrenal insufficiency including orthostatic dizziness and nausea. Hyperprolactinemia has also been detected in up to 24% patients with IH. As both imaging studies and symptoms may be mistaken for pituitary adenomas, with cases of transsphenoidal resection reported, it is crucial to recognize the clinical significance of this phenomenon in order to provide adequate therapy and avoid unnecessary procedures.

Comments

American College of Physicians Internal Medicine Meeting, April 27-29, 2023, San Diego, CA

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