What is the cause of a lump behind the ear (mastoid region)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 14, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

Differential Diagnosis for a Lump Behind the Ear

Single Most Likely Diagnosis

  • Lymphadenopathy: This is the most common cause of a lump behind the ear, often due to a viral or bacterial infection, and can be reactive, meaning it's a response to an infection elsewhere in the body, such as a cold or sinus infection.

Other Likely Diagnoses

  • Cyst or Abscess: Sebaceous cysts or abscesses can form behind the ear, often due to a blocked oil gland or infection. These can be painful and may need to be drained.
  • Mastoiditis: An infection of the mastoid bone, which is located behind the ear. It can cause a lump or swelling in this area and is often associated with ear pain and fever.
  • Benign Tumor: Such as a lipoma or a neurofibroma, which are non-cancerous growths that can occur behind the ear.

Do Not Miss Diagnoses

  • Malignant Tumor: Although less common, a lump behind the ear could be a sign of a malignant tumor, such as a lymphoma or a metastasis from another cancer. Early detection is crucial for treatment.
  • Parotid Gland Tumor: Tumors of the parotid gland, which is located near the ear, can present as a lump behind the ear. While most are benign, some can be malignant.
  • Infectious Diseases: Certain infectious diseases like tuberculosis or cat-scratch disease can cause lymphadenopathy behind the ear, which, if missed, could lead to serious health complications.

Rare Diagnoses

  • Branchial Cleft Cyst: A congenital anomaly that can present as a lump behind the ear, often becoming apparent during childhood but can sometimes be diagnosed in adults.
  • First Branchial Cleft Anomalies: These are rare congenital anomalies that can present with a lump, discharge, or infection behind the ear.
  • Ramsay Hunt Syndrome: A rare neurological disorder caused by the varicella-zoster virus, which can cause a lump or swelling behind the ear, along with facial paralysis and ear pain.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.