Increased bone alkaline phosphatase and isolated subcortical bone uptake of technetium-99m hydroxymethylene diphosphonate in the lower extremities in a patient with Graves' disease: a distinctly unusual variant of Graves' acropachy.
BACKGROUND
Thyroid acropachy is an extreme manifestation of autoimmune thyroid disease characterized by soft tissue swelling and periosteal bone changes, usually occurring in the fingers, toes, and lower extremities. Here, a patient with a distinctly unusual variant of thyroid acropachy is presented.


METHODS
The patient was a 48-year-old woman with Graves' disease and mild ophthalmopathy, who was euthyroid after treatment with Methimazole. Because of a persistently elevated serum alkaline phosphatase (ALP) with elevated bone fraction, a bone scan was performed. This showed increased uptake in the subcortical areas of the lower extremity bones. On questioning, she admitted to mild pain in her lower extremities. She had no other features of thyroid acropachy. Secondary causes of increased ALP, such as cancer, liver disease, and vitamin D deficiency, were excluded by appropriate tests. Therefore, and in view of the patient's underlying Graves' disease, a diagnosis of thyroid acropachy was made.


CONCLUSIONS
Periosteal reaction in the long bones of the lower extremities is unusual in thyroid acropachy, and when it occurs, it is more likely to be associated with overt pain or prominent extrathyroidal manifestations of Graves' disease. This patient very likely had a variant of thyroid acropachy. This variant may be underreported because of its generally asymptomatic nature.
Ogrin
Cristina
C
Berwick Hospital-Medicine, Berwick, Pennsylvania 18603, USA. crisogrin@aol.com
D000469:Alkaline Phosphatase / Q000097:blood / Q000378:metabolism*; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000201:enzymology*; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging; D006111:Graves Disease / Q000000981:diagnostic imaging* / Q000201:enzymology*; D006801:Humans; D008875:Middle Aged; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives; D013977:Tibia / Q000000981:diagnostic imaging
D019275:Radiopharmaceuticals; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D000469:Alkaline Phosphatase; D013669:Technetium Tc 99m Medronate