technetium-tc-99m-medronate and Hypocalcemia

A 59-yr-old man with chronic renal failure was admitted for evaluation of generalized skeletal pain and frontal bone mass, which was lytic on radiography. Bone scintigraphy demonstrated several foci of moderately increased uptake, without involvement of the skull mass. Radiographs of these lesions were compatible with brown tumors. Serum parathormone level was elevated and CT demonstrated a lower right cervical mass, consistent with parathyroid tumor. Following the removal of the mass and decrease in parathormone levels, the patient suffered from a prolonged period of hypocalcemia and his bone pain worsened. Repeat bone scintigraphy showed an increase in the number and intensity of the areas of focal uptake, consistent with hungry bone syndrome. This flare-up phenomenon is due to an increase in bone metabolism and is an uncommon finding following parathyroidectomy for primary hyperparathyroidism.

Topics: Bone and Bones; Bone Diseases, Metabolic; Carcinoma; Humans; Hyperparathyroidism; Hypocalcemia; Kidney Failure, Chronic; Male; Middle Aged; Parathyroid Neoplasms; Parathyroidectomy; Radionuclide Imaging; Technetium Tc 99m Medronate

A case of false-negative Tc-99m MDP bone scintigrams, taken at one and two weeks for pathologic fractures in a patient with metabolic bone disease and a super-scan appearance, is described. The patient had renal osteodystrophy, and postparathyroidectomy hypocalcemia. Postoperative seizures caused multiple pathologic fractures. Initial scans were negative for focal tracer localization in the presence of a continued super-scan appearance. After months of calcium and vitamin D replacement therapy, fracture sites became positive on Tc-99m MDP imaging. The observations in this case lend credence to the hypothesis of Tc-99m MDP binding by immature collagen in the production of a super scan in metabolic bone disease, as well as that of Tc-99m MDP chemisorption to calcium hydroxyapatite crystal in fracture healing. In addition, aluminum toxicity, common in chronic renal osteodystrophy, may have played a role in the delayed fracture healing.

Topics: Adult; Chronic Kidney Disease-Mineral and Bone Disorder; Diagnostic Errors; Fractures, Spontaneous; Humans; Hypocalcemia; Male; Parathyroid Glands; Postoperative Complications; Radionuclide Imaging; Seizures; Technetium Tc 99m Medronate

Topics: Adult; Calcinosis; Diphosphonates; Humans; Hypocalcemia; Hypokalemia; Leg; Male; Muscles; Muscular Diseases; Radionuclide Imaging; Shoulder; Technetium; Technetium Tc 99m Medronate