Manifestation of rheumatoid arthritis after transsphenoidal surgery in a patient with acromegaly

Acromegalic arthropathy is one of the most frequent manifestations occurring in acromegaly patients. In contrast, rheumatoid arthritis (RA) is a rare clinical complication in acromegaly patients. Here, we report a 70-year-old Japanese woman with acromegaly, who complained of bilateral finger stiffness and polyarthralgia two months after transsphenoidal surgery of a growth hormone (GH)-secreting pituitary adenoma. Postoperative levels of serum GH and insulin-like growth factor-1 (IGF-1) were markedly decreased without any secretory deficiency of other anterior pituitary hormones. Hand X-ray did not show typical RA changes; however, erosive changes in carpal bones were clearly detected by magnetic resonance imaging with gadolinium enhancement. Based on the levels of serological markers in the patient following surgery including C-reactive protein, rheumatoid factor and matrix metalloproteinase-3, anti-rheumatic therapy was subsequently commenced. Regardless of the levels of GH and IGF-1, acromegaly patients frequently complain about joint-related symptoms even after remission. Therefore, careful observation of bone erosive changes and immunological activity in acromegaly patients is required when joint-related symptoms persist.