title: Ectopic parathyroid carcinoma presenting with hypercalcemic crisis, ectopic uptake in bone scan and obstruction of superior vena cava.
abstract: A 28-year-old Chinese man diagnosed with hypercalcemic crisis was referred for Tc-99m sestamibi parathyroid imaging, which revealed a massive sestamibi-avid lesion in right-site of upper mediastinum. Contrast-enhanced CT demonstrated the lesion encroached and obstructed bilateral innominate veins and superior vena cava. Tc-99m methylene diphosphonate (MDP) bone scan and SPECT displayed ectopic uptakes in the lungs and stomach. Preoperative suspicion of parathyroid carcinoma prompted an en bloc surgery, which was confirmed in histopathology. Our case showed that although ectopic parathyroid carcinoma causing hypercalcemic crisis, extraskeletal microcalcifications, and great vessel obstruction is rare, parathyroid imaging and bone scan can help solve these diagnostic challenges.
authors.affiliation: Department of Nuclear Medicine, Tianjin Medical University General Hospital, Tianjin, PR China. james_mencius@hotmail.com
authors.forename: Zhaowei
authors.initials: Z
authors.lastname: Meng
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Yujie
authors.initials: Y
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.forename: Jian
authors.initials: J
authors.lastname: Tan
mesh_terms: D000328:Adult; D001692:Biological Transport; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000378:metabolism*; D006801:Humans; D006934:Hypercalcemia / Q000150:complications* / Q000473:pathology*; D008297:Male; D010282:Parathyroid Neoplasms / Q000150:complications* / Q000000981:diagnostic imaging*; D013479:Superior Vena Cava Syndrome / Q000150:complications*; D015899:Tomography, Emission-Computed, Single-Photon