Medical Terminology for a Bump on the Forehead
The medical term for a bump on the forehead depends on the underlying pathology, but common terms include lipoma, dermoid cyst, epidermoid cyst, osteoma, hematoma, or subcutaneous mass.
Common Benign Lesions
Lipomas are the most frequently encountered benign masses on the forehead, presenting as slow-growing, solitary swellings that occur more commonly in males with a mean age of 48 years 1. These lesions:
- Are composed of mature fat cells and typically located in the submuscular plane beneath the frontalis muscle 2, 3, 1
- Present as round or oval, smooth, dome-shaped tumors where the overlying skin glides freely over the surface 2
- May be specifically termed subaponeurotic lipomas when located between the galea aponeurotica and periosteum 2
- Can have variants such as fibrolipoma, which contains a mixture of fibrous connective tissue and presents with firm or soft consistency 3
Congenital Lesions
Dermoid cysts and epidermoid cysts are important differential diagnoses, particularly in pediatric populations:
- Frontonasal dermoid sinus tracts (DSTs) appear as innocuous bumps that could be misdiagnosed as pimples or comedones, with 10-30% extending intracranially through the foramen cecum 4
- Subcutaneous dermoids present as palpable masses that may have associated skin findings 4
- These require imaging (CT and MRI) to detect potential intracranial extension before any surgical intervention 4
Other Pathologies
Additional diagnostic considerations include:
- Encephaloceles: Focal herniation of meninges with or without brain tissue through a skull defect, more common in Asian populations when frontal 4
- Osteomas: Bony masses requiring osteotome or rasp for removal 5
- Mucoceles: Cystic masses that can extend from the frontal sinus into subcutaneous tissue, though patients typically present with ophthalmic symptoms first 6
- Hematomas: Post-traumatic fluid collections, as blunt trauma has been postulated to contribute to forehead mass formation 1
Clinical Pitfalls
The most critical error is failing to exclude intracranial extension before attempting surgical excision 4, 1. Key warning signs include:
- Midline location suggesting possible dermoid sinus tract with intracranial connection 4
- Drainage of clear fluid (potentially CSF) from the lesion 4
- Associated neurological symptoms or signs of increased intracranial pressure 4
Always obtain imaging (CT and/or MRI) for midline forehead masses before surgical intervention to rule out intracranial communication, as 10-30% of frontonasal DSTs extend intracranially despite innocent appearance 4.