Lysis of osteoblastic lesions in prostatic cancer: a sign of progression.

Osteoblastic metastases from prostatic cancer often increase in density after successful endocrine treatment. Regrowth of malignancy, at the time of relapse, may cause osteolytic changes in previously stable sclerotic lesions. Four illustrative case reports are presented. Fading of sclerotic lesions on radiographs, accompanied by bone destruction, signifies disease progression.