Solitary plasmocytoma of bone is a rare type of plasma cell tumor. We present a case of a solitary extramedullary plasmacytoma of the frontal bone presenting as an asymptomatic forehead lump with clinically benign characteristics. This case highlights the need for a high index of suspicion when dealing with enlarging subcutaneous lumps of the forehead and scalp. The significance of this lies in the appropriate sequencing of investigations and the implementation of the necessary treatment regimen.