Endocrine Abstracts

: A 67-year-old lady, previously fit and well, presented with chest pain. She denied gastrointestinal or urological symptoms. There was no history of depression, psychosis, previous hip fracture or steroid use. She had regular menstrual cycles until hysterectomy at 50 years of age. She doesn’t smoke or drink alcohol. Her mother and father had oesophageal and lung cancer respectively with no family history of hypercalcemia. On examination, she was normotensive with BMI 23.3 kg/m². Blood investigations revealed incidental hypercalcemia with elevated parathyroid harmone (PTH) levels. Routine bloods including FBC, TSH, renal function were normal with eGFR of 88 ml/min/1.73 m^2. Coeliac and myeloma screen were negative and Vitamin D level was 66.8 nmol/l. DEXA scan confirmed severe osteoporosis and she was started on weekly alendronate. Chest X-ray showed mediastinal widening; CT chest showed a cystic mediastinal mass. Parathyroid SPECT CT showed MIBI avid lesion in anterior mediastinum but no discernible parathyroid adenoma in the neck. Video-assisted thoracoscopic surgery (VATS) biopsy of mediastinal mass was inconclusive. Her mediastinal mass was subsequently removed at thoracotomy. Excision biopsy confirmed evidence of thymoma (Type B1), but no evidence of parathyroid tissue. In the interim, she was treated for breast carcinoma with wide local excision and radiotherapy. Her pre and post-operative corrected serum calcium and PTH values are shown in Table 1. We report a case of thymoma presenting with hypercalcemia, osteoporosis and hyperparathyroidism. Histology confirmed thymoma with a possible ectopic PTH production. Post-operative PTH levels normalised initially but then started increasing, even though serum calcium levels remained normal. This raised PTH could be secondary to bisphosphonates but surprisingly PTH values were normal during immediate post-operative period. Also interestingly, she did not exhibit any signs or symptoms of myasthenia gravis.