Areolar gland abscess. A tender, palpable abscess on the periphery of the areola may result from infection and inflammation of Montgomery's glands.
Breast cyst. A breast cyst that enlarges rapidly may cause acute, localized, and usually unilateral pain. A breast nodule may be palpable. http://en.wikipedia.org/wiki/Breast_cyst
Fat necrosis. Associated findings include ecchymosis; erythema of the overriding skin; a firm, irregular, fixed mass; and skin retraction signs.http://www.healthatoz.info/diseases/fat-necrosis.htm
Intraductal papilloma. the primary sign is a serous or bloody nipple discharge, usually from only one duct.http://www.nlm.nih.gov/medlineplus/e...cle/001238.htm
Mammary duct ectasia. Burning pain and itching around the areola may occur, although ectasia usually produces no symptoms initially. http://en.wikipedia.org/wiki/Duct_ectasia_of_breast
Mastitis. Unilateral pain may be severe, particularly when the inflammation occurs near the skin surface. Breast skin is typically red and warm at the inflammation site; peau d'orange may be present. Palpation reveals a firm area of induration. http://en.wikipedia.org/wiki/Mastitis
Sebaceous cyst (infected). Breast pain may be reported with this cutaneous cyst. Associated findings include a small, well-delineated nodule; localized erythema; and induration. http://en.wikipedia.org/wiki/Sebaceous_cyst