Pituitary microadenoma presenting with refractory migraine: A case report

Background Headache is a common, heterogeneous manifestation of pituitary disease and may occur independently of tumour size. Hormonally active pituitary microadenomas may present with migraine-like phenotypes, making it challenging to distinguish primary migraine from headache attributed to pituitary disease, particularly when structural imaging findings are subtle. Case A 31-year-old woman with a more than 15-year history of migraine, which had progressed to chronic migraine with aura, presented with progressive worsening of her headache that became refractory to multiple preventive therapies. Over time, she noticed subtle systemic changes suggestive of acromegaly, including weight gain, facial changes and enlarged hands. Magnetic resonance imaging (MRI) identified a small pituitary microadenoma. Although insulin-like growth factor 1 (IGF-1) was mildly elevated on several occasions (≤1.4 x upper limit of normal (ULN)), growth hormone levels suppressed to <0.4 µg/L following a 75 g glucose challenge. [ 11C ]methionine positron emission tomography (MET-PET) showed focally increased radiotracer uptake at the pituitary microadenoma site. The patient underwent transsphenoidal resection of the adenoma. Histopathology confirmed a sparsely granulated GH–secreting pituitary adenoma. Following surgery, her headache resolved completely, accompanied by several clinical features suggestive of acromegaly. Conclusion This case suggests that biologically active pituitary disease may exacerbate pre-existing migraine through hormonal and neuropeptide-mediated mechanisms, even in the absence of significant structural abnormalities. Treatment-refractory migraine accompanied by evolving systemic features should prompt consideration of secondary endocrine contributors to headache.