To describe a case of advanced squamous cell carcinoma (SCC) of the scalp with osseous erosion, dural involvement, and various neurologic manifestations.

Clinical case description.

A 73-year-old female with a history of a 9-cm SCC of the right scalp, treated with radiotherapy and Cemiplimab four months prior, was brought to the hospital after being found down at home with altered mental status. On exam, she was lethargic, confused, and hemiparetic on the left. She sustained a generalized tonic-clonic (GTC) seizure with left gaze deviation. Non-contrast CT demonstrated 1.3 x 0.3 x 3.7 cm SCC invading the calvarium, with underlying pneumocephalus and a 5-mm thick hypodense subdural collection suspicious for empyema. The patient was started on empiric broad-spectrum antibiotics. Fluoroscopic lumbar puncture revealed moderate lymphocytic pleocytosis with normal glucose; cultures and meningitis panel were negative for infection. She was started on levetiracetam and had no further seizures during hospitalization. On hospital day fourteen, she underwent resection of SCC, craniectomy, wound washout, mesh cranioplasty, and pedicle flap repair of the scalp defect with neurosurgery and plastic surgery. The operation revealed necrotic appearing calvarium and invasion of the dura with underlying inflammation but no apparent empyema. Wound cultures did not grow any organisms. The patient recovered from the procedure with a return to her neurologic baseline. Subsequent imaging demonstrated resolution of the subdural collection.