Benign Breast Disease Benign breast hyperplasia is a benign breast disease caused by the abnormal development and involution of the mammary gland, essentially resulting in disarray of the normal breast structure due to proliferation and incomplete restoration of the mammary parenchyma and stroma. Owing to the complex and varied morphological characteristics in histopathology, there is no uniform clinical nomenclature for this condition.

Fibrocystic breast disease is a benign breast condition caused by abnormal development and regression of the breast tissue, leading to disordered normal breast structure due to proliferation and incomplete involution of the breast stroma and parenchyma. Due to the complex and diverse morphological features observed in tissue pathology, the condition has been referred to by various names in clinical literature. In English literature, it is known as mammary gland disease, fibrocystic breast disease, fibrocystic changes of the breast, etc. According to ICD-10, it is termed as mammary duct ectasia, fibrocystic changes in the breast, and mammary gland hypertrophy. Surgical textbooks refer to it as fibrocystic disease of the breast or mammary gland disease. In the 2016 expert consensus, the condition has been unified under the term "fibrocystic breast disease." It is not a tumor, nor does it involve inflammatory changes; rather, it is a benign breast condition.

- Imbalance of estrogen and progesterone levels, leading to excessive proliferation and incomplete involution of the breast parenchyma.

- Abnormal quality and quantity of breast hormone receptors, resulting in varying degrees of proliferation in different parts of the breast.

- Elevated prolactin levels, affecting breast growth, development, lactation function, and the function of the hypothalamic-pituitary-gonadal axis.

Any factors that lead to changes in sex hormones or their receptors can increase the risk of this condition.

These factors include age, menstrual history, pregnancy history, lactation history, history of oral contraceptive use, dietary structure, and psychosocial factors.

Breast pain

Clinically, breast pain is often the initial symptom, with cyclic pain mostly being physiological, whereas non-cyclic pain may likely be influenced by neural, drug-related, and extramammary factors.

Patients in the early stages may complain of pain related to the menstrual cycle, while those with fibrocystic breast disease often experience clearly localized non-cyclic pain.

Breast nodules or masses

These can include granular nodules, cord-like nodules, localized or diffuse glandular thickening, with multiple nodules being common. The masses are generally small, with varying shapes and may change with the menstrual cycle.

Nipple discharge

Approximately 3.6% to 20% of patients experience nipple discharge, which is often a pale yellow, colorless, or milky fluid, with bloody discharge being less common.

After seeking medical attention, a doctor will conduct a comprehensive diagnosis based on the patient's medical history, physical examination, and relevant tests, including necessary biopsies.

The diagnosis primarily relies on typical presentations (breast tenderness and masses associated with the menstrual cycle) and imaging examinations such as ultrasound, followed by a preliminary diagnosis made by the doctor. Subsequently, a pathological biopsy is performed to confirm the diagnosis and rule out other diseases.

The lesions of fibrocystic breast disease are often diffuse, and local surgical excision cannot address the fundamental issue. The disease itself does not necessitate surgical treatment; rather, surgical intervention is primarily aimed at avoiding misdiagnosis or removing suspicious lesions. It is important to note that when patients present with atypical hyperplasia, early prevention of cancer should be a clinical focus.

Fibrocystic breast disease itself is caused by the disorder of estrogen secretion in women, and there are no effective direct preventive measures. However, healthy dietary and lifestyle habits can have a certain positive impact on preventing the disease.

Currently, there are three main prevention methods for disease progression or malignant transformation: close follow-up, drug intervention, and surgical intervention. In cases of atypical epithelial hyperplasia, presence of contralateral breast cancer or a family history of breast cancer, as well as in older patients with significant proliferation of breast tissue around the mass, consideration can be given to performing a biopsy.