Sclerotic bone metastases from sarcomatoid renal cell carcinoma

Osteoblastic bone metastases from renal cell carcinoma

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.

Case report.

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.

Sclerotic osseous metastases from renal cell carcinoma

This case series describes and illustrates three cases of sclerotic osseous metastases from untreated renal cell carcinoma (RCC). RCC is commonly metastatic to the skeleton but almost always produces lytic metastases, with only three prior reports of sclerotic metastases identified in the literature. Sclerotic metastasis causing low back pain was the initial disease presentation in two of the three patients in this case series and the first manifestation of metastatic disease in one. The most common metastatic sites of RCC, i.e., retroperitoneal lymph nodes, lung, and liver, were not identified in any of the cases, and skeletal involvement with epidural extension was the only site of metastasis in two. Pathologic specimens from all three cases revealed RCC of high nuclear grade.

[Sarcomatoid carcinoma of the kidney: a case report]

Sarcomatoid carcinoma of the kidney is an uncommon tumor associated with a very poor prognosis. Because this tumor can be occasionally difficult to distinguish from renal sarcoma, immunohistochemistry and electronmicroscopy are sometimes necessary for diagnosis. Therapy is actually essentially surgical because if adjuvant therapies should follow radical nephrectomy, no standardized regimen has been at present defined.