Cytodiagnosis of a Cutaneous Clear Cell Malignancy: Metastatic Renal Cell Carcinoma on Chin

摘要

Clear cell type of renal cell carcinoma (RCC) is most common urological malignancy. Several diagnostic challenges arise when it presents as a cutaneous nodule, being an uncommon presentation. Fine needle aspiration cytology (FNAC) of a cutaneous nodule is crucial for distinguishing primary tumours from metastatic tumours because cutaneous metastases represent a terminal stage of illness. Due to considerable overlap of cytomorphological features determination of primary warrants need of detailed clinical history and close inspection of every cytological detail. We report here a case of cutaneous metastasis of RCC on chin in a patient 11 years after nephrectomy. Though there are reports of RCC metastases diagnosed on histology, there are fewer cytology case reports. Cytological differential diagnosis has been discussed for arriving at the final diagnosis in case of clear cell tumours. Early and accurate diagnosis is mandatory for optimal treatment. Cytodiagnosis of cutaneous metastasis of RCC is uncommon due to its low suspicion index in cutaneous nodules. More so, it presents late and an unusual sites due to its resemblance to common dermatological diseases.