Bone biopsy in solitary lesions on bone scan in genitourinary malignancy

What is the significance of solitary bony abnormalities on bone scintigrams of children with malignancy?

This investigation was undertaken to evaluate the significance of solitary bony abnormalities on bone scintigrams of children with known or suspected malignancy. A total of 215 bone scans were performed in 183 children in order to look for possible metastasis over a 10-year period. Forty-nine scans (22.8%) were found to have single lesions, of which 18 were due to uptake at the primary site and were excluded from further consideration. Of the remaining 31 lesions, 13 (41.9%) were confirmed as metastases, 17 lesions were proved to be benign, and 1 indeterminate. Solitary hot spots in children with known or suspected malignancy are common and therefore have to be taken seriously due to their higher malignant potential.

[Solitary hypermetabolic bone focus in the initial extension study of a prostate carcinoma]

56 year old male who was diagnosed of Prostatic Neoplasm by transrectal biopsy after elevated PSA level was found by chance in a routine control. The initial extension study with abdominal and pelvic CT did not show significant radiological abnormalities. This was followed by a whole body bone scintigraphy with 99mTc-MDP that showed a solitary hypermetabolic lesion within skull. A SPECT study placed this lesion at the left occipital region. An MRI and a CT head scan were carried out to characterize the isotopic lesion, finding no bone abnormalities to justify the mentioned uptake. Given the absence of a radiological benign diagnosis, a further FDG-PET scan was carried out which did not show either increased glycolytic activity at the left occipital region, or in the prostatic gland. In order to guide the biopsy, a CT head scan was repeated which showed what appeared to be an incipient blastic lesion in the scale of the left occipital bone, establishing the differential diagnosis between a metastasis and a benign process. The anatomopathologic analysis of the bone tissue describes a necrotic process without inflammatory reaction (osteonecrosis).