Differential Diagnosis

The following differential diagnosis is based on the provided symptoms and characteristics of the mass.

• Single most likely diagnosis:

  • Calcified lymph node: The description of the mass as rock or bone hard, fixed, non-movable, and painless, along with its location under the earlobe, suggests a calcified lymph node. The fact that it has been present for at least 1.5 years without change and does not cause any other symptoms supports this diagnosis.

• Other Likely diagnoses:

  • Salivary gland stone (sialolithiasis): Although less common, a stone in the salivary gland could present as a hard, fixed mass. The location under the earlobe, near the parotid gland, makes this a plausible option.
  • Benign bone or cartilage tumor: Tumors such as an osteoma or a chondroma could present as a hard, fixed mass. However, their growth pattern and the fact that they are typically slow-growing make them less likely than a calcified lymph node.
  • Lipoma or other soft tissue tumor: Although the mass is described as hard, some soft tissue tumors can feel firm or hard, especially if they are deep-seated. However, the rock-hard consistency and fixed nature make this less likely.

• Do Not Miss diagnoses:

  • Malignant lymphoma or metastasis: Although the mass has been stable for 1.5 years, which is atypical for most malignancies, it is crucial not to miss a potential malignancy. Lymphoma or metastasis to a lymph node could present as a hard, fixed mass.
  • Parotid gland malignancy: Given the location near the parotid gland, a malignancy in this gland, although rare, must be considered to ensure timely diagnosis and treatment.

• Rare diagnoses:

  • Eagle syndrome: This condition involves an elongated styloid process or calcified stylohyoid ligament, which can cause a palpable mass in the neck. However, it typically presents with pain and dysphagia, which are not mentioned in the scenario.
  • Branchial cleft cyst: These cysts can present as masses in the neck but are usually softer and may become infected, leading to pain and swelling, which does not match the description provided.