Solitary rib lesions in bone scans of patients with breast carcinoma

The aetiology of solitary rib lesions detected on bone scans was evaluated retrospectively. Seventy-five patients with breast carcinoma, and each with a solitary hot spot on a bone scan, were included in the study. The aetiology of the solitary rib lesions was determined by using all available clinical, laboratory and radiological data, and was clarified in 65 of the 75 patients, and not clarified in the remaining 10. In 17 of those 65 (26.1%), the aetiology of increased uptake was malignant; while in 48 of the 65 (73.8%) it was benign in origin. Linear lesions were mainly metastatic in origin (seven of nine, 77.7%) whereas focal lesions were mostly benign in origin (46 of 56, 82.19%). In the group of 16 hot spots located at the anterior rib end, 14 (87.5%) were benign, and two (12.5%) were malignant in origin. The relation between mastectomy side and the distribution of anterior and anterior rib end localization of hot spots was also investigated. Twenty-three of 32 rib lesions (71.8%) were on the same side as the surgery. In conclusion, solitary rib lesions on bone scans in patients with breast carcinoma are frequently benign in origin, especially if they are focal and located at the anterior rib end.