M 50 with a nodule on the scalp that had developed over the last few months.
A 2 cm partially cystic dermal nodule on an old craniotomy scar the scalp was thought to be a pilar cyst on clinical examination.
Past history of renal cell carcinoma with a single metastatic nodule in the brain five years earlier.
After a left nephrectomy, the brain nodule was initially treated by radiotherapy and subsequently by surgical resection 2 years later.
Nineteen months after craniotomy the patient developed a scalp nodule within the craniotomy scar. There was no evidence of any other tumor.

Fig 1 : H&E low magnification

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Fig 2 : H&E high magnification

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Fig 3 : Immunostaining with RCC antibody

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ANSWER: What is your diagnosis? DS72