Scalp : Anatomy, Lesions And Surgical Considerations by teachers@tatvakrishna

SCALP : ANATOMY

(Mnemonic SCALP)

1. Skin – Thick and hair-bearing, Contains numerous sebaceous glands and sweat glands, Richly supplied with blood vessels and nerves

2. Connective Tissue (Dense)- Dense, fibrous layer, Contains blood vessels and nerves, Vessels are firmly anchored → profuse bleeding when cut (they cannot retract easily)

3. Aponeurosis (Galea Aponeurotica) – A tough, tendinous sheet connecting: Frontalis muscle (front), Occipitalis muscle (back), Responsible for scalp movement

4. Loose Areolar Tissue – Also called the “danger area of the scalp”, Allows movement of the upper 3 layers over the skull, Contains emissary veins connecting superficial veins to intracranial venous sinuses → pathway for infection spread to the brain

5. Pericranium – The periosteum of the skull bones, Loosely attached (except at sutures), Important in bone nutrition and repair

Key Clinical Points Heavy bleeding: due to rich vascular supply and fixed vessels Infections spread easily: via emissary veins in the loose areolar tissue Scalp wounds gape: if the aponeurosis is cut Hematomas: Above aponeurosis → diffuse swelling, Below pericranium → limited by sutures (cephalhematoma)

LESIONS OF SCALP

1. Subcutaneous Swellings (in Skin & Connective Tissue) – These are superficial swellings.

Sebaceous cyst –  Most common scalp swelling, Arises from sebaceous glands , slow-growing, painless, punctum present, firm

Dermoid cyst – Congenital lesion,  Usually near lines of embryonic fusion

Lipoma – Soft, lobulated, mobile swelling

2. Subaponeurotic (in Loose Areolar Tissue) – Located in the danger area of scalp

Subaponeurotic hematoma – Blood collects in loose areolar tissue, Diffuse swelling, can spread widely across scalp

3. Subperiosteal Swellings (Below Pericranium)

Cephalhematoma –  Common in newborns (birth injury), Blood collects beneath pericranium

4. Vascular Swellings –

Hemangioma –  Benign tumor of blood vessels, Soft, compressible, may increase on crying

Arteriovenous Malformation (Cirsoid aneurysm) – Abnormal connection between arteries and veins, Pulsatile swelling with bruit

5. Inflammatory Swellings

Abscess – Painful, red, warm swelling, May follow infection or trauma

6. Neoplastic Swellings

Benign: lipoma, fibroma

Malignant: rare (e.g., metastasis)

7. Calcified lesions  – Calcified lesions of the scalp are swellings where calcium deposition occurs within a lesion, making them hard on palpation and sometimes visible on X-ray/CT.

1. Pilar cyst (Trichilemmal cyst) – Most common calcified scalp lesion, Arises from hair follicle root sheath, Common in middle-aged females, Firm to hard swelling, No punctum (unlike sebaceous cyst)

2. Pilomatricoma – Benign tumor from hair matrix cells, Common in children and young adults, Stony hard swelling, Irregular surface, Often shows calcification

3. Calcinosis cutis – Deposition of calcium in skin/subcutaneous tissue, Due to Trauma – Metabolic disorders

4. Osteoma – Arises from skull bone, Hard, immobile swelling, May be mistaken for scalp lesion

Quick  Points Most common swelling → Sebaceous cyst Danger area involvement → Subaponeurotic hematoma Does not cross sutures → Cephalhematoma Pulsatile swelling → AV malformation

SURGICAL INCISION OF SCALP

Surgical incisions of the scalp are designed keeping in mind the anatomy, vascularity, and cosmetic outcome of the scalp.

General Principles

• Incisions should be planned along natural skin lines (Langer’s lines)
• Prefer along hair direction to minimize visible scarring
• Avoid unnecessary damage to the galea aponeurotica
• Control bleeding carefully (scalp is highly vascular)

Types of Surgical Scalp Incisions
1. Linear Incision – Straight incision over the lesion, Used for small cysts (e.g., pilar or sebaceous cyst), Simple and quick

2. Elliptical (Fusiform) Incision– Ellipse-shaped around lesion, Allows complete excision with primary closure, Prevents dog-ear deformity

3. Curvilinear Incision – Curved incision following scalp contour, Common in neurosurgical procedures

4. Question Mark Incision – Classic incision in neurosurgery (e.g., craniotomy), Starts anterior to ear, curves upward and backward

5. Bicoronal (Coronal) Incision – Extends from one ear to the other across the scalp, Used in: Craniofacial surgery, Skull exposure, Gives wide access with good cosmetic result (hidden in hair)

Important Surgical Considerations Bleeding Control : Scalp bleeds profusely due to rich blood supply Methods: Pressure, Hemostats, Ligatures Wound Gaping : If galea aponeurotica is cut, wound gapes widely, Needs proper layered closure Closure Technique : Close in layers – Galea aponeurotica, Skin, Use non-absorbable sutures for skin