Endocrine Abstracts

Background: The correlation linking Myasthenia Gravis (MG) and pituitary adenomas is exceedingly uncommon. Our thorough investigation of medical literature uncovered merely eight documented cases showcasing this association. Notably, five of these cases specifically involved adenomas that secreted prolactin¹. Two instances implicated a non-functional pituitary adenoma in this rare association². Solely one case was identified involving a growth hormone (GH)-secreting adenoma in this context³. So, to our knowledge, this marks the inaugural documentation of a non-secreting adenoma detected in a patient diagnosed with myasthenia.

Case detail : A 72 years of age gentleman, Mr X, was admitted to the hospital on 8/11/23 due to eye symptoms and was found to have both a pituitary macroadenoma and myasthenia gravis. He had a medical history including retinopathy, cataract surgery, YLC procedure, hypertension, type 2 diabetes, prostate cancer, and bowel cancer. Over two months, he experienced double vision and eyelid drooping, worsening by the end of the day and more pronounced in the left eye. Additionally, he reported dull eye discomfort intermittently. Mr X also had new-onset breathlessness and fatigue for about three weeks, worse with exertion and at day’s end. He felt more tired than usual but had no issues with swallowing, breathing, or speech. Physical examination revealed bilateral ptosis with equally sized pupils reacting to light. An incidental finding of a 13×12×16 pituitary macroadenoma was discovered on MRI orbit without compressing the optic chiasm or optic nerve abnormalities. His CT head (19/10/23) showed no significant intracranial issues, and subsequent imaging ruled out thymus malignancy. Blood tests indicated acetylcholine receptor antibodies at a level of 292, TSH receptor antibodies <0.3, TPO <4, random cortisol 775, and ACTH 54, Prolactin of 158 mu/l (normal), growth hormone level of 0.74 mg/l (Normal), IGF-1 is 20.9 nmol/l (Normal) and with normal FSH. LH and testosterone levels. He commenced IVIG treatment followed by an up-titrating course of prednisolone under neurology guidance, monitoring CBGs. He will receive continued care from neurology and endocrine clinics, with a follow-up contrast MRI scheduled in six months.

Conclusion : In conclusion, the simultaneous presentation of myasthenia gravis and pituitary macroadenomas represents an exceedingly rare occurrence. This unique co-occurrence underscores the complexity and diversity of potential medical conditions and highlights the importance of comprehensive assessment and collaborative multidisciplinary care for such exceptional cases. Continued research and clinical observation are essential to better understand the underlying mechanisms linking these two distinct conditions when they occur together