Progressive diaphyseal dysplasia (Engelmann disease(: scintigraphic-radiographic-clinical correlations.

Four patients (2 males, 2 females; ages 15-47 yrs.) with variable clinical, radiographic, and scintigraphic manifestations of progressive diaphyseal dysplasia (PDD) or Engelmann disease were studied with 99mTc methylene diphosphonate bone imaging and radiographic skeletal surveys. Comparison of the results of the two imaging procedures showed that some affected bones were scintigraphically normal but radiographically abnormal and vice versa. These findings suggest that the lesions of PDD may mature, causing a significant decrease in disease activity, and that abnormally increased radiopharmaceutical accumulation during bone scintigraphy appears to be a sensitive indicator of disease activity.