Splenius Capitis Cysts

A splenius capitis cyst is a rare, fluid‑filled sac that forms in or near the splenius capitis muscle in the back of your neck. Though uncommon, these cysts can cause pain, stiffness, and lumps in the neck.

A splenius capitis cyst is a benign (non‑cancerous) sac filled with fluid or semi‑solid material, located within or just beside the splenius capitis muscle. These cysts may grow slowly and can cause local symptoms by pressing on nearby tissues.

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Anatomy of the Splenius Capitis Muscle

Understanding where a cyst appears starts with knowing the muscle’s anatomy.

Structure & Location

• Shape & Size: Broad, strap‑shaped muscle on each side of the back of the neck.

• Layer: Lies just under the skin and trapezius muscle, above deeper neck muscles.

Origin

• Lower half of the nuchal (neck) ligament.

• Spinous processes of C7 to T3 (sometimes T4) vertebrae.

Insertion

• Mastoid process of the temporal bone (behind the ear).

• Lateral third of the superior nuchal line of the occipital bone (back of the skull).

Blood Supply

• Occipital artery (branch of the external carotid artery).

• Deep cervical artery (branch of the costocervical trunk).

Nerve Supply

• Dorsal rami of the middle cervical spinal nerves (C3 and C4).

Primary Functions

1. Head Extension: Tilts head backward.

2. Head Rotation: Turns head to the same side.

3. Lateral Flexion: Bends neck sideways toward the same side.

4. Neck Stability: Helps maintain upright head posture.

5. Assisting Respiration: Aids chest expansion when breathing hard.

6. Fine Head Control: Works with other muscles for smooth head movements.

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Types of Splenius Capitis Cysts

Cysts in this muscle can be categorized by their origin or content:

1. Synovial Cyst: Fluid leaks from nearby vertebral joints.

2. Ganglion Cyst: Jelly‑like fluid without a true lining.

3. Epidermoid Cyst: Skin cells trapped under the surface.

4. Dermoid Cyst: Developmental cyst containing skin structures.

5. Branchial Cleft Cyst: Congenital pouch near neck muscles.

6. Lymphatic (Lymphangioma) Cyst: Dilated lymph vessels.

7. Parasitic Cyst: Caused by parasites (e.g., hydatid disease).

8. Abscess (Infectious) Cyst: Pus‑filled pocket from infection.

9. Retention (Mucoid) Cyst: Blocked gland fluid.

10. Neoplastic Cyst: Cystic form of a benign tumor (e.g., cystic schwannoma).

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Causes

1. Facet Joint Wear & Tear (arthritis)

2. Trauma or Injury (whiplash, blow to neck)

3. Repetitive Strain (poor posture, desk work)

4. Congenital Defects (branchial cleft anomalies)

5. Skin Cell Blockage (epidermoid cyst formation)

6. Infections (bacterial abscess)

7. Parasitic Infections (echinococcus/hydatid)

8. Blocked Lymph Channels (lymphangioma)

9. Gland Duct Obstruction (retention cyst)

10. Tumor Degeneration (cystic change in benign tumors)

11. Inflammatory Diseases (rheumatoid arthritis)

12. Autoimmune Conditions (lupus, Sjögren’s)

13. Metabolic Disorders (diabetes‑related poor healing)

14. Post‑surgical Changes (scar tissue trapping fluid)

15. Radiation Therapy (tissue damage leads to cyst)

16. Chemical Irritation (injected medications)

17. Poor Nutrition (weak tissue structure)

18. Age‑Related Changes (degeneration of joints)

19. High‑impact Sports (micro‑tears and fluid build‑up)

20. Smoking (impaired healing, inflammation)

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Symptoms

1. Neck Lump (palpable bump)

2. Local Pain (dull or sharp)

3. Stiffness (reduced neck motion)

4. Headaches (base of skull)

5. Muscle Spasm (tightness around cyst)

6. Radiating Pain (to shoulder or arm)

7. Tingling or Numbness (nerve compression)

8. Weakness (in neck or arm)

9. Redness (overlying skin)

10. Warmth (indicates inflammation)

11. Swelling (increased size over days/weeks)

12. Fever (if infected)

13. Night Pain (wakes you up)

14. Difficulty Swallowing (rare, large cysts)

15. Difficulty Turning Head (pain‑limited motion)

16. Visible Asymmetry (one side looks different)

17. Tension in Shoulders (referred)

18. Grinding Sensation (joint‑based cyst)

19. Fatigue (chronic discomfort)

20. Skin Dimpling or Pitting (adhesions)

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Diagnostic Tests

1. Physical Exam (palpation, motion tests)

2. Ultrasound (fluid vs. solid)

3. X‑ray (bone changes, joint arthritis)

4. CT Scan (detailed bone and soft tissue view)

5. MRI (best for soft tissue and cyst detail)

6. CT Myelography (if nerve root involvement)

7. PET Scan (rule out malignancy)

8. Fine‑Needle Aspiration (fluid sampling)

9. Core Needle Biopsy (tissue sample)

10. Fluid Analysis (cell count, crystals, culture)

11. Blood Tests (CBC, ESR, CRP for inflammation)

12. Serology (parasite or autoimmune markers)

13. EMG/Nerve Conduction (nerve compression)

14. Ultrasound Elastography (fluid stiffness)

15. Fluoroscopy (dynamic joint imaging)

16. Bone Scan (rule out bone disease)

17. Histopathology (under microscope)

18. Immunohistochemistry (tumor markers)

19. Culture & Sensitivity (infection)

20. Genetic Testing (rare congenital cases)

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Non‑Pharmacological Treatments

1. Rest & Activity Modification

2. Heat Therapy (warm packs)

3. Cold Therapy (ice packs)

4. Ultrasound Therapy (deep heating)

5. Shockwave Therapy

6. TENS (Transcutaneous Electrical Nerve Stimulation)

7. Massage Therapy

8. Myofascial Release

9. Dry Needling

10. Acupuncture

11. Stretching Exercises

12. Strengthening Exercises

13. Posture Correction

14. Ergonomic Workstation Setup

15. Cervical Traction

16. Cervical Collar (short‑term)

17. Yoga (neck‑friendly poses)

18. Pilates (core stability)

19. Chiropractic Adjustment

20. Osteopathic Manipulation

21. Hydrotherapy (water exercises)

22. Kinesio Taping

23. Foam Rolling

24. Breathing Exercises (relaxation)

25. Stress Management (mindfulness)

26. Weight Management (reduce strain)

27. Ergonomic Pillow (neck support)

28. Ergonomic Chair (lumbar support)

29. Work/Rest Cycling (micro‑breaks)

30. Education & Self‑Care (neck safety)

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Drugs

1. Ibuprofen (NSAID)

2. Naproxen (NSAID)

3. Diclofenac (NSAID)

4. Acetaminophen (paracetamol)

5. Celecoxib (COX‑2 inhibitor)

6. Meloxicam (NSAID)

7. Tramadol (weak opioid)

8. Codeine (opioid)

9. Cyclobenzaprine (muscle relaxant)

10. Baclofen (muscle relaxant)

11. Prednisone (oral steroid)

12. Methylprednisolone (injection)

13. Lidocaine (local anesthetic injection)

14. Gabapentin (neuropathic pain)

15. Pregabalin (neuropathic pain)

16. Albendazole (anti‑parasitic)

17. Praziquantel (anti‑parasitic)

18. Penicillin (antibiotic)

19. Cefazolin (antibiotic)

20. Methotrexate (for rheumatoid arthritis)

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Surgical Treatments

1. Open Excision (complete removal)

2. Minimally Invasive Endoscopic Excision

3. Ultrasound‑Guided Aspiration (fluid drainage)

4. Arthroscopic Facet Joint Cyst Removal

5. Cervical Laminectomy & Decompression

6. Microsurgical Cyst Resection

7. Aspiration + Sclerotherapy (inject sclerosant)

8. Excisional Biopsy (diagnostic + therapy)

9. Fascia Release (reduce tissue tension)

10. Reconstructive Closure (cosmetic repair)

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Prevention Strategies

1. Maintain Good Posture (neutral spine)

2. Ergonomic Work Setup

3. Regular Neck‑Strengthening Exercises

4. Avoid Repetitive Neck Strain

5. Use Proper Pillow Support

6. Warm‑Up Before Sports

7. Early Arthritis Management

8. Limit High‑Impact Activities

9. Quit Smoking (improves healing)

10. Balanced Diet & Hydration

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When to See a Doctor

• Rapid Growth of neck lump

• Severe or Worsening Pain that limits daily life

• Neurological Signs (numbness, weakness)

• Fever or Infection Signs (redness, warmth)

• Difficulty Swallowing or Breathing

• No Improvement after 2–4 weeks of self‑care

• Night Pain that wakes you up

• Skin Changes (ulceration, dimpling)

• History of Cancer (rule out malignancy)

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Frequently Asked Questions

1. What is a splenius capitis cyst?
   A fluid‑filled sac in or near the splenius capitis muscle at the back of your neck.

2. Are splenius capitis cysts common?
   No. They are rare compared to other neck cysts.

3. What causes these cysts?
   Causes range from arthritis and injury to congenital defects and infections.

4. Can a splenius capitis cyst go away on its own?
   Small cysts sometimes shrink, but many need treatment if they cause symptoms.

5. How are these cysts diagnosed?
   Physical exam plus imaging like ultrasound or MRI. Sometimes fluid sampling.

6. What treatments are available?
   Options include physical therapy, medications, and—if needed—aspiration or surgery.

7. Is surgery always needed?
   No. Many cysts can be managed non‑surgically unless they cause severe symptoms or grow.

8. What are the risks of surgery?
   Infection, nerve injury, scarring, or cyst recurrence are possible.

9. Can cysts recur after removal?
   Yes—especially if the underlying cause (e.g., joint arthritis) isn’t treated.

10. Are there home remedies?
    Yes: rest, heat/cold packs, gentle exercises, and posture correction can help.

11. Can I work out with a splenius capitis cyst?
    Light exercise is okay, but avoid heavy or repetitive neck strain until you see a doctor.

12. Will I feel pain during aspiration?
    A local anesthetic is used, so you should feel minimal discomfort.

13. Can these cysts turn cancerous?
    Almost never. They are almost always benign.

14. How long is recovery after surgery?
    Most people return to normal in 2–6 weeks, depending on the procedure.

15. Who treats splenius capitis cysts?
    Usually an orthopedic surgeon, neurosurgeon, or ENT specialist.

Disclaimer: Each person’s journey is unique, treatment plan, life style, food habit, hormonal condition, immune system, chronic disease condition, geological location, weather and previous medical  history is also unique. So always seek the best advice from a qualified medical professional or health care provider before trying any treatments to ensure to find out the best plan for you. This guide is for general information and educational purposes only. Regular check-ups and awareness can help to manage and prevent complications associated with these diseases conditions. If you or someone are suffering from this disease condition bookmark this website or share with someone who might find it useful! Boost your knowledge and stay ahead in your health journey. We always try to ensure that the content is regularly updated to reflect the latest medical research and treatment options. Thank you for giving your valuable time to read the article.

The article is written by Team Rxharun and reviewed by the Rx Editorial Board Members

Last Update: April 16, 2025.

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