Most changes in breast tissue aren't cancerous. Some breast conditions are harmless and don't need any further treatment. Other breast conditions could mean Hormonal changes · Cysts · Fibroadenomas · Ductal carcinoma in situ. Apr 9, - A woman's breast composition is determined by the amount of dense and non-dense tissue she has, which in turn causes lumps. Women diagnosed with scattered fibroglandular breast tissue may have benign (non-cancerous) lumps or cysts in one or both of their breasts.