What is the best treatment approach for a patient with a cyst on their back?

Treatment of Back Cysts

For a cyst on the back, the optimal treatment depends entirely on the cyst type: simple epidermoid/sebaceous cysts require only observation or simple excision if symptomatic, while spinal synovial cysts causing radiculopathy should initially be managed conservatively with physical therapy and analgesics, reserving surgical resection for cases with intractable pain, neurological deficits, or failed conservative management.

Initial Assessment and Cyst Classification

The first critical step is determining what type of cyst is present, as this fundamentally changes management:

• Superficial skin cysts (epidermoid, sebaceous, pilar cysts) are benign lesions that can be observed if asymptomatic
• Spinal synovial cysts arise from facet joint degeneration and may cause radiculopathy or back pain 1
• Other considerations include ganglion cysts, Baker's cysts (if posterior knee region), or rare entities like hydatid cysts in endemic areas 2

Management Algorithm for Spinal Synovial Cysts

Conservative Management (First-Line)

Initial conservative treatment should be attempted for all patients without severe neurological deficits, as spontaneous resolution can occur:

• Physical therapy combined with analgesic medication for 3-6 months 3
• Epidural steroid injections may provide temporary relief, though failure rates approach 50% 1
• Serial imaging is reasonable if symptoms improve, as cysts can spontaneously regress 3

Key caveat: Observation alone is appropriate only when there is no intractable pain 1. The natural history shows that some cysts resolve without intervention, making aggressive early surgery potentially unnecessary 3.

Indications for Surgical Intervention

Surgery becomes necessary when:

• Intractable pain persists despite 3-6 months of conservative management 1
• Significant motor weakness or progressive neurological deficits develop 1
• Multiple synovial cysts are present 1
• Associated spondylolisthesis exists 1

Surgical Approach Selection

For patients requiring surgery, the optimal technique is facet-sparing minimally invasive resection:

• Partial hemilaminectomy (70% of cases) or hemilaminectomy (27%) provides excellent access while preserving stability 4
• Contralateral minimally invasive approach using tubular retractors avoids facet disruption and better visualizes the cyst-dura interface 5
• Complete cyst resection without fusion achieves excellent/good outcomes in 94% of patients at long-term follow-up (mean 9.3 years) 4

Fusion is reserved for specific scenarios:

• Significant pre-existing instability or spondylolisthesis 1
• Multiple recurrent cysts 1
• Severe degenerative changes requiring bilateral laminectomy 1

Alternative Interventional Options

For high-risk surgical candidates with intractable pain:

• Percutaneous cyst aspiration with steroid injection under fluoroscopic guidance can provide relief 6
• Important limitation: Failure rate approaches 50%, and this should be considered a temporizing measure 1
• Successful aspiration has been reported, with complete pain resolution in select cases 6

Outcomes and Recurrence

Long-term surgical outcomes are favorable:

• 78% of patients remain pain-free at mean 9.3-year follow-up 4
• Recurrence requiring reoperation occurs in 7% of cases 4
• Delayed fusion needed in 9% after initial cyst resection 4
• Complication rates are low, though dural injury risk is increased due to cyst adherence 4

Management of Simple Skin Cysts

For superficial epidermoid or sebaceous cysts on the back:

• Asymptomatic cysts require no treatment
• Symptomatic or cosmetically concerning cysts can be excised via simple surgical removal
• Infected cysts require incision and drainage followed by delayed definitive excision after inflammation resolves

Critical pitfall: Avoid labeling benign lesions unnecessarily, as this creates anxiety and leads to overtreatment 2. Conservative observation is appropriate for most simple cysts.