A mastectomy is a surgical procedure often performed as a treatment for breast cancer. While the surgery is generally successful, the body’s response to the removal of tissue can sometimes lead to complications during recovery. Among the most frequent post-operative issues reported by patients is the formation of a seroma. Seromas are common following breast surgery, with incidence rates widely reported between 15% and 85% of cases, depending on the extent of the operation. Understanding this complication allows patients to recognize the symptoms and manage expectations for recovery.
Understanding Seromas
A seroma is a collection of serous fluid—a clear, pale yellow fluid—that accumulates in a pocket beneath the skin near the surgical site. This fluid is a mix of blood plasma and lymphatic fluid that leaks from damaged small blood vessels and lymphatic channels following surgery. The primary cause of a seroma after a mastectomy is the creation of a “dead space” where the breast tissue and, often, lymph nodes have been removed.
The body responds to surgical trauma with an inflammatory reaction, increasing fluid production to aid healing. When the tissue that normally fills this space is gone, the fluid collects in the resulting cavity. Seromas are distinct from hematomas (collections of blood) and abscesses (pockets of pus indicating infection). While a seroma is not cancerous, a large collection can cause discomfort and potentially delay the start of other treatments like radiation or chemotherapy.
Recognizing the Signs
Seromas typically become noticeable days to weeks after the surgical procedure, often appearing after temporary surgical drains have been removed. The most common presentation is localized swelling or bulging near the incision line on the chest wall or under the armpit, especially if lymph nodes were removed. This area may feel full, tight, or squishy, similar to a soft, fluid-filled lump beneath the skin.
While usually painless, a large or rapidly growing seroma can cause mild discomfort, tenderness, or a feeling of pressure at the site. Patients should regularly monitor the size of any swelling and check for any drainage from the incision, which may be clear or slightly bloody. Contact a healthcare provider immediately if the swelling increases rapidly, causes significant pain, or if the skin over the area becomes warm, red, or tender, as these can be signs of an infection.
Treatment and Management
Many small seromas are managed conservatively, as the body’s lymphatic system often reabsorbs the fluid naturally over several weeks to a few months. However, if a seroma is large, symptomatic, or causing tension on the incision line that could impede wound healing, medical intervention is necessary. The standard management approach is percutaneous needle aspiration, sometimes referred to as paracentesis.
This procedure involves the healthcare provider cleaning the skin and inserting a fine, sterile needle and syringe into the fluid pocket to withdraw the serous fluid. Aspiration is usually performed in a clean, outpatient setting and may be nearly painless. The goal is to relieve pressure and facilitate the collapse of the space, allowing the tissue layers to adhere.
It is common for fluid to re-accumulate, requiring the aspiration procedure to be repeated multiple times over several weeks until the space closes. For persistent or recurrent seromas, the surgeon may consider reinserting a temporary surgical drain to provide continuous, low-level suction.
In conjunction with aspiration, compression garments may be used to apply gentle, constant pressure over the area to help prevent fluid buildup. In rare cases of refractory seromas that do not resolve with repeated aspiration, more involved procedures like sclerotherapy (injecting an irritating substance to encourage scar tissue formation) or surgical excision of the seroma lining may be considered.
Reducing the Risk
While seroma formation is a common consequence of mastectomy, patients can take specific steps to minimize the risk of fluid accumulation. Following the surgeon’s instructions regarding movement restrictions is important in the immediate post-operative period. Limiting heavy lifting and avoiding strenuous activity that strains the chest or arm muscles helps reduce the inflammatory response and fluid production.
Prophylactic use of prescribed compression garments or binders, when recommended by the surgical team, helps gently compress the skin flaps against the chest wall. This external pressure reduces the potential “dead space” where fluid can collect. If surgical drains are in place upon discharge, meticulous care, including proper stripping and emptying of the reservoirs, is necessary for effective fluid removal. Adherence to the surgeon’s schedule for drain removal is also important, as removing them too early is a known risk factor for subsequent seroma formation.