title: Osteoblastic bone metastases from renal cell carcinoma.
abstract: BACKGROUND
  RCC accounts for only 2-3% of all cancers. Due to its' non-specific symptoms disease is often diagnosed in advanced stage. Disseminated RCC frequently produces bone metastases that are almost always highly destructive, hyper vascularized and purely osteolytic.
  
  
  METHODS
  In this article we describe a case of a 71-year old male patient with disseminated osteoblastic bone metastases from renal cell carcinoma (RCC), and present a short review of published literature reporting cases of osteoblastic bone metastases from RCC. Our patient presented with thoracic pain aggravated by movement. He was diagnosed with predominantly osteoblastic bone metastases in the skeleton of thoracic and lumbar vertebra along with metastases in iliac bones, ribs, humerus and clavicles. Initially, origin of bone metastases was unknown, but later a small tumor in patient's right kidney was identified. Microscopic evaluation of the open bone biopsy showed clear cell RCC with sarcomatoid differentiation.
  
  
  CONCLUSIONS
  Although, due to its' rarity, RCC is not included in the primary differential diagnosis in patients with osteoblastic metastases, such rare cases suggest that RCC may be considered in the diagnosis when there no other primary tumor is found.
authors.affiliation: Clinical Radiology Institute, UMC Ljubljana, Ljubljana, Slovenia.
authors.forename: Vladka
authors.initials: V
authors.lastname: Salapura
authors.affiliation: Clinical Department of Haematology, UMC Ljubljana, Ljubljana, Slovenia.
authors.forename: Irena
authors.initials: I
authors.lastname: Zupan
authors.affiliation: Sector of Medical Oncology, Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Bostjan
authors.initials: B
authors.lastname: Seruga
authors.affiliation: Department of Pathology, Institute of Oncology Ljubljana, Ljubljana, Slovenia.
authors.forename: Gorana
authors.initials: G
authors.lastname: Gasljevic
authors.affiliation: Clinical Radiology Institute, UMC Ljubljana, Ljubljana, Slovenia.
authors.forename: Pavel
authors.initials: P
authors.lastname: Kavcic
keywords: osteoblastic bone metastases; renal cell carcinoma