Differential Diagnosis for Mole Peeling and Bleeding Next to Nipple

Single Most Likely Diagnosis

• Benign Nevus with Irritation or Trauma: This is the most likely diagnosis given the description of peeling and bleeding, which could be due to mechanical irritation or trauma to a pre-existing mole, especially considering its location next to the nipple where friction or irritation from clothing could occur.

Other Likely Diagnoses

• Seborrheic Keratosis: These are common, benign growths that can appear as pigmented lesions and may bleed or peel, especially if irritated.
• Dermatofibroma: A benign skin growth that can occur after minor injury, which might bleed or peel if irritated.
• Inflammatory or Infectious Process: Conditions like eczema (dermatitis), folliculitis, or impetigo could cause skin lesions that peel and bleed, though they are less likely to be mistaken for a mole.

Do Not Miss Diagnoses

• Melanoma: Although less likely, melanoma is a critical diagnosis not to miss. The ABCDE rule (Asymmetry, Border irregularity, Color variation, Diameter >6mm, Evolving) can help identify suspicious lesions. A new or changing mole, especially one that bleeds, warrants further investigation.
• Paget's Disease of the Nipple: A rare form of breast cancer that can present with eczematous changes, bleeding, or a nipple discharge. Its location next to the nipple makes this a crucial differential to consider.

Rare Diagnoses

• Merkel Cell Carcinoma: A rare, aggressive skin cancer that can present as a firm, painless nodule and may bleed.
• Kaposi's Sarcoma: A rare cancer that can cause lesions on the skin, which might bleed or peel, though it's more commonly associated with immune suppression.

Each of these diagnoses should be considered in the context of a thorough clinical evaluation, including a detailed history and physical examination, and may require further diagnostic testing such as a biopsy for definitive diagnosis.