Differential Diagnosis for a White Nodule on the Eyelid

• Single most likely diagnosis
  • Chalazion: A common, benign condition characterized by a small, usually painless nodule or lump on the eyelid due to a blocked oil gland. It's the most likely diagnosis given the description of a white nodule, which could be indicative of the characteristic appearance of a chalazion.
• Other Likely diagnoses
  • Stye (Hordeolum): An acute, localized infection or inflammation of the eyelid margin involving hair follicles of the eyelashes (external hordeolum) or meibomian glands (internal hordeolum). It presents as a painful, red nodule on the eyelid.
  • Xanthelasma: A condition characterized by small, yellowish patches or nodules on the eyelids due to accumulation of fat, often associated with hyperlipidemia. While not typically white, the description could be misleading, and xanthelasma is a common eyelid lesion.
  • Papilloma: A benign growth on the eyelid, which could appear as a nodule. These are usually harmless but can be similar in appearance to more serious conditions.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed)
  • Basal Cell Carcinoma: The most common form of skin cancer, which can present as a nodule on the eyelid. Early detection is crucial for effective treatment.
  • Squamous Cell Carcinoma: Another form of skin cancer that can appear on the eyelid, often as a firm, red nodule. It's less common than basal cell carcinoma but more aggressive.
  • Merkel Cell Carcinoma: A rare, aggressive skin cancer that can appear as a firm, painless nodule on the eyelid. It has a high risk of metastasis, making early diagnosis critical.
• Rare diagnoses
  • Keratoacanthoma: A low-grade, or sometimes considered benign, malignancy of the skin that can appear as a nodule on the eyelid. It resembles squamous cell carcinoma but typically has a more rapid growth phase followed by spontaneous resolution.
  • Sebaceous Gland Carcinoma: A rare, aggressive cancer originating from the sebaceous glands of the eyelid. It can masquerade as a benign condition like a chalazion or blepharitis, making diagnosis challenging.
  • Lymphoma: Though extremely rare, lymphoma can manifest as a nodule on the eyelid. It would be an unusual presentation but is a consideration in the differential diagnosis due to its potential severity.