Differential Diagnosis for Dark Mass Inner Upper Eyelid

• Single most likely diagnosis
  • Melanosis or pigmented lesion: This is a common and benign condition that can cause a dark mass to appear on the inner upper eyelid due to an increase in melanin production.
• Other Likely diagnoses
  • Nevi (moles): These are benign growths that can appear as dark masses on the eyelid and are relatively common.
  • Cyst or abscess: An infection or blockage of the meibomian gland can cause a cyst or abscess to form, which may appear as a dark mass if it becomes filled with pus or debris.
  • Allergic or inflammatory reaction: Certain allergies or inflammatory conditions can cause dark discoloration or masses on the eyelid.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Malignant melanoma: Although less common, melanoma can present as a dark mass on the eyelid and is potentially life-threatening if not diagnosed and treated early.
  • Basal cell carcinoma or other eyelid cancers: These are rare but serious conditions that require prompt medical attention.
  • Orbital cellulitis: An infection of the tissues surrounding the eye, which can cause swelling, redness, and potentially a dark mass appearance if an abscess forms.
• Rare diagnoses
  • Vascular malformations: Abnormal formations of blood vessels that can appear as a dark mass due to the color of the blood within them.
  • Dermatologic conditions (e.g., lentigo, seborrheic keratosis): Certain skin conditions can cause dark lesions that might be mistaken for a mass.
  • Foreign body reaction: In rare cases, a reaction to a foreign body embedded in the eyelid can cause a dark mass to form.