Ductal ectasia: This condition is characterized by the dilation of the milk ducts in the breast, often causing a lump or thickening near the nipple, and can lead to nipple discharge and tenderness. It is more common in older women, making it a likely diagnosis for an elderly patient.

Breast cyst: Breast cysts are fluid-filled sacs within the breast that can cause lumps and tenderness. They are common in women, especially as they age, and can occur near the nipple.
Mastitis: An infection of the breast tissue, mastitis can cause tenderness, swelling, and sometimes a lump. While more common in lactating women, it can occur in non-lactating women as well, including the elderly.
Fibrocystic changes: These are benign changes in the breast tissue that can cause lumps, tenderness, and sometimes nipple discharge. They are very common and can occur at any age, including in elderly women.

Breast cancer: Although less likely than some other diagnoses, breast cancer must always be considered, especially in elderly patients, as it can present with a lump or thickening near the nipple, nipple discharge, or tenderness. Missing a diagnosis of breast cancer could have severe consequences.
Paget's disease of the breast: A rare form of breast cancer that starts on the nipple and extends to the areola, Paget's disease can cause nipple tenderness, itching, and a lump. It is crucial not to miss this diagnosis due to its potential for malignancy.

Fat necrosis: This is a rare condition where the fatty tissue in the breast becomes damaged, leading to the formation of a lump. It can cause tenderness and is more common after trauma to the breast but can occur spontaneously.
Periductal mastitis: A rare inflammatory condition that affects the ducts under the nipple, periductal mastitis can cause nipple retraction, tenderness, and sometimes a lump. It is more common in smokers and can be challenging to diagnose.