What is the recommended evaluation and management for a subgaleal temporal cyst?

Subgaleal Temporal Cyst: Evaluation and Management

Initial Assessment

For a subgaleal temporal cyst, obtain imaging with ultrasound or CT scan to confirm the diagnosis and rule out deeper extension, followed by surgical excision as definitive treatment.

The subgaleal space lies between the galea aponeurotica and the periosteum of the cranial bones 1. These cysts present as soft, ill-defined, fluctuant, highly mobile scalp swellings that are not limited by suture lines, making them clinically distinct from other scalp masses 2.

Diagnostic Workup

Clinical Examination

• Palpation characteristics: Look for a hemispherical, firm, fluctuant, non-tender mass that does not pulsate and does not increase with crying 3
• Location: Most commonly presents over the anterior fontanelle or temporal region 3
• Mobility: The swelling should be highly mobile due to the loose areolar tissue in the subgaleal space 2

Imaging Studies

• Plain radiographs: Can help exclude bony involvement 3
• CT scan of the head: Recommended to confirm diagnosis, assess extent, and detect any osteomyelitis or intracranial extension 1
• Ultrasound: Transfontanelle sonography can confirm the diagnosis in infants 3

Important caveat: If you are clinically confident in the diagnosis of a simple subgaleal fluid collection in an infant without signs of infection, imaging may not be necessary 2. However, for temporal cysts or any atypical presentations, imaging is prudent to rule out complications.

Management Algorithm

For Congenital/Benign Subgaleal Cysts

Surgical excision is the treatment of choice 3, 4:

• Approach: Access incision behind the hairline for cosmetic purposes 4
• Dissection plane: For temporal lesions, dissect just superficial to the deep temporal fascia 4
• Complete excision: Total excision under general anesthesia prevents recurrence 3
• Histologic confirmation: Send specimen for pathology to confirm epidermal inclusion cyst or other benign pathology 3

For Infected Subgaleal Collections

If signs of infection are present (erythema, warmth, fever):

• Immediate CT imaging: Essential to detect osteomyelitis or intracranial extension 1
• Surgical drainage: Immediate drainage of abscess with debridement of necrotic tissue 1
• IV antibiotics: Target Staphylococcus aureus as the predominant organism 1
• Wound management: Consider negative pressure wound therapy (VAC dressing) for closure 1

For Simple Subgaleal Fluid Collections in Infants

• Conservative management: Late-presenting subgaleal fluid collections (weeks after birth) resolve spontaneously without intervention 2
• No aspiration needed: These benign collections do not require drainage 2
• Observation only: Monitor for spontaneous resolution 2

Key Pitfalls to Avoid

• Do not misdiagnose as sebaceous cyst: Subgaleal collections can mimic infected scalp cysts but require different management 1
• Do not delay imaging in atypical cases: Failure to image can miss serious complications like osteomyelitis or intracranial extension 1
• Do not perform incomplete excision: Partial removal leads to recurrence; complete excision is necessary 3
• Consider endoscopic approach: For cosmetic benefit, endoscope-assisted excision through hairline incisions provides excellent outcomes without visible scarring 4

Special Considerations

For refractory or recurrent cases: If hematoma recurs after aspiration, consider angiography to evaluate for vascular abnormalities and potential embolization of feeding vessels 5.

Postoperative follow-up: Monitor for recurrence at 1-24 months; properly excised lesions should not recur 4.