Most benign breast lumps are caused by fibrocystic [FI-bro-SIS-tic] changes in the breast, which are a normal part of the menstrual cycle. These lumps generally consist of fluid-filled cysts formed within the breast tissue and do not increase your chance of getting breast cancer. Breast swelling and tenderness can be associated with fibrocystic changes. In addition, your breast may feel lumpy and occasionally present a cloudy discharge from the nipple.
Fibroadenomas [FI-bro-ad-eh-NO-mas] and intraductal papillomas [pa-pi-LO-mas] are two other types of benign breast lumps and abnormalities. Fibroadenomas generally consist of smooth, rubbery or hard lumps that move easily within the breast tissue. These abnormalities very rarely develop into breast cancer and are most commonly found in teenagers and African American women. Intraductal papillomas are wart-like lumps that form within a milk duct. They sometimes cause nipple discharge and are recommended to be surgically removed.*
Your doctor will advise you on the proper course of action regarding a benign breast lump or abnormality. Occasionally, the decision is made to remove the cyst either through a surgical or minimally invasive procedure. Regardless of this decision, you will want to continue to perform a monthly breast self-exam and get an annual breast exam and mammogram.
The good news is that 80% of biopsies are benign according to the FDA.
* Working up an intraductal papilloma is imperative due to the possibility of harboring occult carcinoma.  It is classified as a high-risk precursor lesion due to its association with atypia, ductal carcinoma in situ (DCIS), and carcinoma.  Surgical excision with complete tumor removal is the recommended treatment. 
Source: Li A, Kirk L. Intraductal Papilloma. [Updated 2020 Aug 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020 Jan