Renal cell carcinoma: an unusual case of sclerotic metastasis

Abstract

DESCRIPTIONA 44-year-old man presented with a 3-month history of low back pain affecting mainly the left lumbar and gluteal regions. Physical examination revealed restricted back movement with tenderness over lumbar spinal processes. Straight leg raising test was negative. Laboratory examinations showed an elevated erythrocyte sedimentation rate (ESR; 116 mm) and a high level of alkaline phosphatase (1000 IU/L). Serum levels of calcium, albumin and phosphorus were within the normal range. The pelvis and lumbar spine X-ray showed diffuse and heterogenous osteosclerotic lesions (figure 1). The chest X-ray was normal. Blood parathyroid hormone and prostate-specific antigen levels were normal. Pelvic ultrasound showed a regular and homogenous prostate with no enlargement and no postmictional residue. An abdominal contrastenhanced CT showed the existence of a 3 cm heterogenous tumour at the lower pole of the right kidney (figure 2). Osteomedullary biopsy was then performed. Histopathology showed cells with copious clear cytoplasm and nuclei with prominent, eosinophilic nucleoli. Immunohistochemistry revealed positivity for Vimentin, cytokeratin (CAM 5.2) and epithelial membrane antigen. The diagnosis of osteoblastic bone metastases from renal cell carcinoma (RCC) was established. Palliative radiation therapy was indicated.Bone metastases in RCC occur in 20-25% of cases and are mainly osteolytic.1 Rare cases of sclerotic metastases revealing an RCC have been reported. 2 3 Sclerosis is very common in Paget's disease. The diagnosis of bone metastases should be considered when elevation of ESR is found. In such cases, osteomedullary biopsy is necessary to differentiate among these various entities.Learning points ▸ The diagnosis of bone metastases should be considered when sclerotic lesions and an increase in erythrocyte sedimentation rate are found. ▸ Renal cell carcinoma should be kept in mind in front of sclerotic bone metastasis especially when no other primary tumour is found.

The Challenges of Renal Cell Carcinoma Metastatic to the Spine: A Systematic Review of Survival and Treatment

“…The literature search identified 1440 unique results, where 47 articles met the inclusion criteria with a total of 807 patients included in the data analysis ( Figure 1 ). 1 , 10 , 11 , 13 , 15 , 18 – 60 Demographics, presenting features, treatment, and survival information were compiled for those patients with known status. The majority of patients were male (75.5%), and the mean age at diagnosis of RCC spine metastasis was 56.7 years.…”

Hypercalcemia in a patient with a bowing femur

“…4 The main differential diagnosis of PDB is condensing bone metastases, notably in the presence of high serum calcium levels. 6 Hypercalcemia is not a frequent feature of PDB.…”

“…Rarely, hypercalcemia may occur in patients with active polyostotic PDB during immobilization, fracture, or dehydration 4–10 …”

“…4 The main differential diagnosis of PDB is condensing bone metastases, notably in the presence of high serum calcium levels. 6 Hypercalcemia is not a frequent feature of PDB. When it occurs, it should raise the possibility of an association with another condition such as bone metastases, primary hyperparathyroidism, and multiple myeloma.…”

“…27 Rarely, hypercalcemia may occur in patients with active polyostotic PDB during immobilization, fracture, or dehydration. [4][5][6][7][8][9][10] Regarding the therapeutic management of PDB, bisphosphonates are indicated in the presence of pain and increased ALP. 2,3 Reid et al showed that a single infusion of zoledronic acid leads in most cases to rapid and sustained clinical and biological remission.…”