Benign intraductal papilloma: This is the most common cause of a solitary lesion near the nipple-areola complex, often presenting with nipple discharge. The proximity to the nipple and the typical age of presentation (40-60 years) make this a likely diagnosis.

Ductal carcinoma in situ (DCIS): Although less common than benign papillomas, DCIS can present as a lesion near the nipple-areola complex, especially if it involves the ducts close to the nipple.
Invasive ductal carcinoma: Similar to DCIS, invasive ductal carcinoma can present as a lesion near the nipple but is generally associated with more pronounced symptoms and signs.
Sebaceous cyst or epidermal inclusion cyst: These benign lesions can occur anywhere on the skin, including near the nipple-areola complex, and may be mistaken for more serious conditions.

Paget's disease of the breast: A rare form of breast cancer that presents with eczematous changes of the nipple-areola complex. It is crucial to consider this diagnosis due to its potential for underlying invasive cancer.
Inflammatory breast cancer: Although rare, this aggressive form of breast cancer can present with skin changes, including near the nipple-areola complex, and has a high mortality rate if not promptly treated.

Adenoma of the nipple: A rare, benign tumor of the nipple that can mimic more serious conditions.
Syringomatous adenoma of the nipple: Another rare, benign tumor that can present as a lesion near the nipple-areola complex.
Nipple-areolar complex melanoma: Although melanoma can occur anywhere on the skin, its occurrence on the nipple-areola complex is rare and can be easily overlooked.