Differential Diagnosis for Benign Palatable Lump in Armpit Causing Arm Numbness
- Single Most Likely Diagnosis
- Lipoma: A benign tumor composed of fat tissue, which can cause compression of nearby nerves, leading to numbness when the arm is bent at a 90-degree angle. The location in the armpit and the description of the lump as palpable and benign support this diagnosis.
- Other Likely Diagnoses
- Cyst (e.g., sebaceous or epidermoid): These can also present as palpable lumps and, depending on their size and location, could compress nerves, leading to symptoms like numbness when the arm is bent.
- Neurofibroma: A type of benign nerve tumor that can cause nerve compression symptoms, including numbness, especially if it is located near or involves the nerves of the arm.
- Lymphadenopathy (benign): Enlarged lymph nodes can be palpable and, if large enough, could potentially compress nerves, leading to symptoms like numbness.
- Do Not Miss Diagnoses
- Pancoast Tumor: A type of lung cancer located at the top of the lung that can cause nerve compression, leading to arm numbness and weakness. Although less likely given the description of the lump as benign, it's crucial not to miss this diagnosis due to its severe implications.
- Axillary Abscess or Infection: An infection in the armpit could cause swelling and numbness due to nerve compression or inflammation. This condition requires prompt treatment to avoid serious complications.
- Rare Diagnoses
- Schwannoma: A rare, benign tumor of the nerve sheath that can cause nerve compression symptoms.
- Desmoid Tumor: A rare, benign but locally aggressive tumor that can occur in the armpit and potentially cause nerve compression.
- Soft Tissue Sarcoma: Although rare, sarcomas can present as lumps in the soft tissues, including the armpit, and could potentially cause nerve compression symptoms if they grow large enough.