What is a cyst with channels in the intergluteal cleft under the skin, possibly in a young adult with a sedentary lifestyle or history of trauma to the area?

Pilonidal Cyst (Pilonidal Sinus Disease)

This is most likely a pilonidal cyst, an acquired inflammatory condition of the intergluteal cleft (butt crack) where hair penetrates the skin and creates channels (sinus tracts) under the surface, forming a chronic granulomatous reaction around foreign body material. 1, 2

What This Condition Is

• Pilonidal disease is an acquired inflammatory disorder where loose hairs penetrate the skin in the natal cleft and burrow into the subcutaneous tissue, creating epithelial-lined tracts and channels that can extend in multiple directions 3, 2

• The condition presents as firm nodules or cysts in or near the gluteal cleft, often with visible pits or openings (the "channels" you're describing) that may drain fluid or pus 1, 2

• Histologically, this represents a granuloma organizing around foreign bodies (usually hairs) that fistulizes to the skin through partially epithelialized openings 2

• This is NOT a congenital dermoid cyst despite older teaching—the consensus is that pilonidal disease is acquired through mechanical hair insertion 3, 2

Key Distinguishing Features

Location is critical for diagnosis:

• Pilonidal cysts occur within or immediately adjacent to the intergluteal cleft in the sacrococcygeal region 1, 2
• This distinguishes them from innocent coccygeal dimples (which lie at or below an imaginary line between the tops of the gluteal folds) 4
• The presence of multiple openings or "pits" with visible channels strongly suggests pilonidal disease rather than other cystic lesions 1, 2

Dermoscopic/clinical appearance includes:

• Pink homogenous background with central ulceration or yellowish areas 1
• Peripherally arranged dotted, glomerular, or hairpin vessels 1
• White reticular lines at the periphery 1
• Visible hair shafts may protrude from openings 2

Risk Factors to Consider

• Young adult males (male-to-female ratio 3-4:1, typically late second decade) 1
• Active smoking significantly increases complications and recurrence risk 2
• Sedentary lifestyle, excess weight, poor hygiene, and occupations involving prolonged sitting 2
• History of local trauma or constant friction to the area 3, 5

When to Seek Medical Attention

Immediate evaluation needed if:

• Pain, redness, swelling, or fever develop (suggests abscess formation) 1, 2
• Purulent drainage occurs 2
• The lesion is rapidly enlarging 2

Elective surgical consultation indicated for:

• Bothersome symptoms even without acute infection 2
• Recurrent episodes of inflammation or abscess 2
• Desire to prevent future complications 2

Treatment Approach

For acute abscess/suppuration:

• Emergency incision and drainage in operating room, OR medical management with analgesics, local antiseptics, and sometimes antibiotics 2
• More than 10,000 emergency procedures performed annually in France alone 2

For chronic/elective cases:

• Minimally invasive techniques (extraction of foreign bodies with mechanical debridement or thermal/chemical cautery) are increasingly preferred as they avoid complex wound care while maintaining equivalent recurrence rates to excision 2
• Radical excision with secondary healing remains most commonly performed but carries 10% failure/recurrence risk and requires prolonged wound care 6, 2
• Primary closure after excision (paramedian or flap closure, NOT midline) reduces healing time but increases infectious complications 6, 2
• Marsupialization shows lowest recurrence rates (4%) in some series 6

Critical Pitfalls to Avoid

• Do not confuse with pathologic dermal sinus tracts (DSTs) located above the gluteal cleft on the flat sacrum—these are congenital spinal abnormalities requiring urgent neurosurgical evaluation to prevent meningitis or cord tethering 4

• Do not assume all intergluteal lesions are benign—in patients with inflammatory bowel disease, consider perianal fistulizing Crohn's disease or hidradenitis suppurativa, which require different management 4

• Address modifiable risk factors (smoking cessation, weight management, improved hygiene) before and after surgery to reduce recurrence 2

• Avoid midline primary closure if excision is performed—this technique has higher failure rates 2