Brown tumors of bone are highly vascular, lytic bone lesions representing a reparative cellular process rather than a neoplastic process seen in patients with hyperparathyroidism. These tumors may behave aggressively and can be destructive. We present a case of 33 year old male who presented with progressively increasing swelling in right leg region. A lytic lesion involving right tibia was seen in regional CT which was suspicious for malignancy. Whole body F18-FDG PET-CT was done for further evaluation. PET-CT showed multiple sites of skeletal lesions with a large mass in right lobe of thyroid gland. Biopsy from tibial lesion revealed it to be osteoclast rich tumor raising a possibility of parathyroid mass with multiple brown tumors. Biochemical parameters revealed high Serum Calcium, Serum Total Alkaline Phosphatase and Serum parathyroid hormone (S. PTH). 99mTehnitium Sestamibi (99m Tc MIBI) imaging was done which localized a right superior parathyroid adenoma with a suspicious right inferior parathyroid adenoma. The patient underwent right superior and inferior parathyroidectomy along with right hemithyroidectomy. Intra-operative fresh S.PTH sample was sent which dropped down to 73.4 ng/ml from 1500 ng/ml. Brown tumor is a potential cause of false-positive result in evaluation of a patient for unknown primary tumor or skeletal metastases with F18-FDG PET-CT imaging.

Born and brought up in a town in the state of Punjab, India, after completion of my high school I was selected into one of the prestigious medical institutes of India- Maulana Azad Medical College, New Delhi where I did my graduation. I did my post graduation in Nuclear Medicine from one of the first institutes for Nuclear Medicine, in India- The Institute of Nuclear Medicine and Allied Sciences, Delhi University. During my post graduation when the modality of PET-CT was still in the stage of infancy in India, I started developing a great interest in this field and role it played in oncology. That interest turned into passion for this branch when I started working with the topmost people in the field of oncology at Max Superspeciality Hospital, New Delhi where there is a dedicated Max Institute of Cancer Care. Today PET-CT has become an integral part of the patient treatment and management in oncology and I love playing the part I am entrusted with day in and day out as a Consultant in the Department of Nuclear Medicine.