Unusual metastasis of renal cell carcinoma to index finger of hand without any evidence of primary renal tumour: A rare case

Abstract

Introduction: The site of the unknown primary neoplasm to bone metastasis cannot be identified at the time of diagnosis despite a thorough history, physical examination, appropriate laboratory testing and modern imaging technology (CT, MRI, PET). Sometimes only extensive histopathological investigations on bone specimens can suggest primary malignancy Clinical case: A 61-year-old male presented to orthopedic OPD with complain of swelling over index finger in left hand since 6 months. There was no lymphadenopathy. The patient had undergone radical nephrectomy 2 years ago. The reason for undergoing surgery was not known to patient. & no documentation available. MRI showed lesion having possibility of neoplastic etiology.Grossly well circumscribed tumor, variegated in appearance, Histopathologically tumor cells arranged in nests & sheets with clear cytoplasm & areas of haemorrhage were seen it was diagnosed as Clear Cell Malignant Tumor On IHC PAX 8 vimentin, CD10 & EMA was positive In view of microscopic findings & case history of radical nephrectomy It was diagnosed as Metastatic clear cell carcinoma of Kidney.Conclusion: Renal cell carcinoma is an aggressive malignancy that can metastatize to bone predominantly osteolytic in nature, leading to significant patient morbidity due to the associated skeletal-related Events The pathologists must be aware of metastatic RCC to the bones and consider it in the differential diagnosis of any bone lesion with clear cell features, whether there is a history of primary RCC or not.