Differential Diagnosis for Tonsil Mass

• Single most likely diagnosis
  • Tonsillar carcinoma: This is the most likely diagnosis due to the high incidence of squamous cell carcinoma in the tonsils, especially in adults with a history of smoking or alcohol use.
• Other Likely diagnoses
  • Tonsillitis: Acute or chronic inflammation of the tonsils can cause a mass-like effect, often accompanied by symptoms such as sore throat, fever, and difficulty swallowing.
  • Peritonsillar abscess: A collection of pus behind the tonsils can present as a mass and is usually associated with severe throat pain, fever, and trismus.
  • Lymphoma: Both Hodgkin's and non-Hodgkin's lymphoma can involve the tonsils, presenting as a mass, and are more common in immunocompromised individuals or those with a history of lymphoma.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Metastatic disease: Although rare, metastasis to the tonsils from other primary sites (e.g., lung, breast, or colon cancer) can occur and would have significant implications for treatment and prognosis.
  • Invasive fungal infections: In immunocompromised patients, fungal infections like aspergillosis or histoplasmosis can involve the tonsils and are life-threatening if not promptly treated.
• Rare diagnoses
  • Kaposi's sarcoma: This rare tumor, associated with human herpesvirus 8, can involve the tonsils, especially in immunocompromised patients, such as those with HIV/AIDS.
  • Granulomatosis with polyangiitis (formerly Wegener's granulomatosis): A rare autoimmune disorder that can cause masses or lesions in the tonsils as part of its systemic involvement.
  • Amyloidosis: Deposits of amyloid protein can accumulate in the tonsils, presenting as a mass, although this is exceedingly rare and usually part of systemic amyloidosis.