Renal Cell Carcinoma With Papillary Morphology Presenting as a Frontal Calvarial Metastasis: A Case Report

Calvarial metastasis can be the first clinical sign of renal cell carcinoma (RCC).A 68-year-old woman presented with a 45-day history of an enlarging, firm, fixed, tender 3×3 cm midline frontal swelling, initially thought to be an epidermoid lesion or a metastasis.Positron emission tomography/computed tomography showed a metabolically active right renal mass and lytic skeletal lesions, including a midline frontal calvarial lesion with a soft-tissue component.She underwent right radical nephrectomy and excision of the frontal lesion.Histopathology showed RCC with papillary morphology, World Health Organization/International Society of Urological Pathology grade 4, pT3a, with focal rhabdoid differentiation and tumor necrosis; immunohistochemistry was not performed.The frontal bone lesion was consistent with metastasis.She received sunitinib.About three months after nephrectomy, she developed headache and seizures, and brain imaging showed brain metastases; she received whole-brain radiotherapy.Her relatives later reported that she had died at home.An enlarging, fixed calvarial mass should not be assumed to be a primary cranial lesion; systemic staging is needed, and RCC, including tumors with papillary morphology, should be considered when a renal mass is found.