Case Report: Hyperthyroidism in a patient with spotty skin pigmentation and atrial myxoma (Carney complex): coincidence, association or cause?

Background: Carney complex (CNC) is a rare autosomal-dominant multiple neoplasia syndrome characterised by spotty skin pigmentation, cardiac myxomas and endocrine overactivity. Although thyroid follicular adenomas are common in CNC, the presence of CNC in combination with Graves' disease-related hyperthyroidism is rare, and the pathogenic association between the two conditions remains poorly understood. Case presentation: An 18-year-old Chinese woman presented with palpitations and worsening fatigue over 2 months. She had a 2-year history of Graves' disease (treated with iodine-131 1 year prior) and spotty facial pigmentation since the age of 10 years. Clinical examination revealed a left atrial myxoma, spotty pigmentation and Graves' disease-related hyperthyroidism. A diagnosis of CNC was established clinically based on the presence of two major criteria: a cardiac myxoma and characteristic lentigines. Preoperatively, the patient received 30 mg of methimazole daily and 10 mg of propranolol three times daily for 30 days to normalise her thyroid function. She subsequently underwent complete excision of the left atrial myxoma (dimensions: 6.5 × 4.5 × 2.5 cm) via a median sternotomy with a right atrial approach while under cardiopulmonary bypass. Postoperatively, antithyroid therapy was changed to 100 mg of propylthiouracil three times daily. No complications occurred after the operation. Conclusions: This is the first detailed report of a typical CNC case with concomitant, persistent Graves' disease, suggesting a potential novel association within the CNC spectrum. It underscores the importance of a multidisciplinary approach in managing the complex perioperative needs of patients with CNC.