Pseudoangiomatous stromal hyperplasia (PASH) is a non-cancerous breast condition involving an overgrowth of connective tissue. This benign lesion can sometimes be felt as a lump or thickening in the breast. PASH is a relatively uncommon finding.
What is Pseudoangiomatous Stromal Hyperplasia?
PASH involves an overgrowth of specialized cells called myofibroblasts within the breast’s connective tissue. The condition is considered benign and does not increase the risk of developing breast cancer. Hormonal influences, particularly estrogen and progesterone, are thought to play a role. PASH can grow in coordination with the menstrual cycle. It is most commonly observed in pre-menopausal women, but it can also occur in men, especially those with gynecomastia, and in post-menopausal women, particularly those undergoing hormone replacement therapy.
Symptoms and Diagnosis of PASH
PASH often presents as a painless lump or thickening within the breast tissue. These palpable masses are typically firm and movable, ranging in size from microscopic to as large as 12 centimeters. While usually painless, larger PASH lesions may sometimes cause discomfort or tenderness. Many cases of PASH are discovered incidentally during routine breast imaging, such as mammograms, ultrasounds, or MRIs, performed for other reasons. If a suspicious area is identified, a biopsy is necessary to confirm the diagnosis and differentiate PASH from other breast conditions, including cancerous lesions like angiosarcoma. A core needle biopsy or excisional biopsy allows for microscopic examination of the tissue, which is the definitive diagnostic method.
Management of Pseudoangiomatous Stromal Hyperplasia
The management of PASH depends on several factors, including the size of the lesion, whether it is causing symptoms, and patient preference. For asymptomatic or small lesions, a “watchful waiting” approach may be adopted, involving observation with regular follow-up imaging. This allows healthcare providers to monitor for any changes in the lesion over time. Surgical excision, which involves a small operation to remove the mass, may be recommended for larger, symptomatic, or rapidly growing lesions. Surgical removal is also considered when there is diagnostic uncertainty, meaning it is difficult to definitively rule out other conditions without removing the tissue. Generally, surgical removal of PASH is considered curative.
PASH and Your Long-Term Health
PASH is a benign condition and is not associated with an increased risk of breast cancer. While PASH may sometimes be mistaken for cancer due to its appearance on imaging or palpation, a biopsy definitively confirms its non-cancerous nature. Some individuals with PASH may still have follow-up appointments or continued monitoring, often as part of the initial diagnostic process or to track any changes in the lesion. This follow-up provides reassurance and ensures that any new breast changes are promptly evaluated. The overall outlook for individuals diagnosed with PASH is excellent due to its benign nature and lack of association with cancer.