Clear cell renal cell carcinoma with osseous metaplasia: Rare case report

Osseous metaplasia with clear cell renal cell carcinoma (RCC) is exceedingly rare. There are less than 20 reported cases of osseous metaplasia in association with RCC. We present a case of 39-year-old male patient presented to outpatient department with complaints of pain in the left lumbar region since 4 years. Computed tomography scan revealed a heterogeneous enhanced mass lesion having areas of necrosis and specks of calcification involving the left kidney. Clinicoradiological diagnosis of RCC was made and left radical nephrectomy was performed. Histological sections from the growth revealed features of clear cell carcinoma Fuhrman grade-2 with a focal area of metaplastic bone formation. The prognostic implications of calcification per se are not very clearly mentioned in the literature. Patients with osseous metaplasia generally present with early stage disease and a favorable prognosis. However, few of them were of high grade and poorer prognosis.