What Are Dog Ears After Mastectomy?

Dog ears after mastectomy are bulges or folds of excess skin and fat that protrude at the ends of the surgical scar, most often at the outer edge near the armpit. They form because of the way tissue behaves when a surgeon closes a wound: the skin at the corners bunches up instead of lying flat, creating a visible mound that can look and feel like a small pouch under clothing. The problem is common enough that surgeons have developed multiple techniques specifically to prevent or fix it, yet many patients are caught off guard by its appearance because it was never discussed before their operation.

Why the Tissue Bunches Up

When a surgeon removes breast tissue and pulls the remaining skin together to close the incision, the center of the wound draws inward under tension. The corners of the incision, though, experience a completely different set of forces. Instead of being pulled together neatly, the tissue at each end rotates and compresses. Once that compression exceeds what the skin can absorb and flatten on its own, the excess pushes outward and upward, forming a cone-shaped bulge at the skin’s surface.¹ Think of it like pinching the end of a sleeping bag closed: no matter how tightly you zip the middle, the corners tend to bunch.

The lateral side of a mastectomy scar, where the incision meets the chest wall beneath the arm, is the classic location for a dog ear. That area tends to have more soft tissue and fat than the medial (inner) side, and the natural contour of the body curves away from the incision, making a smooth, flat closure harder to achieve. One research team described the lateral chest wall as a distinct aesthetic zone that deserves its own surgical attention, separate from the breast mound itself.²

Who Is Most at Risk

Dog ears can happen to anyone after mastectomy, but two factors raise the odds substantially: higher body mass index and larger breast size before surgery. Both mean more tissue to redistribute and close over, which amplifies the rotational and compressive forces at the scar’s ends.³ One study that used a combined L-incision and lipoaspiration approach to prevent dog ears reported that the average BMI of its patient group was about 29 and the average mastectomy specimen weighed just over a kilogram, highlighting the volume of tissue involved in higher-risk cases.⁴

Age and skin elasticity also play a role. Younger patients and those with more supple skin tend to see better flattening over time, while older skin or skin that has been stretched by larger breasts may hold onto the excess volume permanently. The type of mastectomy matters as well. A simple or total mastectomy with a standard elliptical incision is the most common setting for lateral dog ears. Skin-sparing mastectomies, which preserve more of the skin envelope for reconstruction, redistribute the problem differently and can sometimes avoid it altogether depending on the reconstruction method used.

More Than a Cosmetic Nuisance

It is tempting to dismiss dog ears as purely a visual concern, but for many patients the impact is physical. The protruding tissue can chafe against bra straps and clothing seams, creating daily irritation. A qualitative study of patients who chose to live flat after mastectomy without reconstruction found that discomfort from dog ears rubbing on bras was a frequently mentioned physical complaint, alongside scar tightness that restricted arm and shoulder movement.⁵ The bulge can make it difficult to find clothing that fits smoothly, and prosthetic breast forms may not sit properly when the lateral contour is uneven.

Patients frequently describe the emotional burden in strong terms. Many report not understanding why the excess tissue was left behind, and some are misinformed by care teams that the bulge is just swelling that will go away. One paper described how women consistently refer to lateral tissue excess as a “dog ear” with varying levels of embarrassment and aversion, often feeling confused about why it exists at all.⁶ That confusion compounds the distress: when something looks wrong and nobody warned you it might happen, the natural assumption is that something went wrong during surgery.

Body Image After Mastectomy

Dog ears sit within a broader landscape of body image disruption after mastectomy. A study of post-mastectomy breast cancer patients found that roughly two-thirds reported some degree of change in how they perceived their body, with strong links between negative body image and feelings of reduced attractiveness, discomfort looking in a mirror, and changes in spousal relationships.⁷ Dog ears alone do not account for all of that distress, but for patients who have chosen aesthetic flat closure, the lateral bulge is one of the few remaining visible markers of the surgery. It can become a persistent focus of dissatisfaction, especially when the patient expected a smooth, flat result.

A systematic review of aesthetic flat closure techniques noted that common patient-reported concerns included asymmetry, excess skin, and inadequate communication from surgeons about what the final result would look like.⁸ The review also flagged a gap in the research: no studies used validated patient-reported outcome instruments, meaning the field is still relying on informal surveys to measure how patients actually feel about their results. That lack of standardized measurement makes it harder to compare techniques or track satisfaction over time in any rigorous way.

Surgical Techniques to Prevent Dog Ears

Surgeons have developed a range of incision designs and closure methods specifically to minimize or eliminate lateral dog ears at the time of mastectomy. A systematic review of these techniques found that the most commonly described approaches were the “fish-shaped” incision, Y-closure patterns, the “tear-drop” incision, and various L-scar techniques.⁹ Each works by reshaping how the skin is cut and sutured so that the lateral corner’s excess tissue is either redistributed or removed before the wound is closed.

One approach pairs an L-shaped incision with lipoaspiration of the lateral chest wall, suctioning out fatty tissue in that zone so there is less volume to bunch up. Another team described a modified M-plasty that folds an additional flap of skin and fat inward during closure, smoothing the lateral contour without extending the scar further toward the back.³ For breast reduction and lift procedures, which face a similar dog-ear problem at the base of vertical incisions, a set of five technical steps applied during surgery kept the revision rate at zero percent over thirteen years in one clinical review.¹⁰

The trade-offs in prevention are worth understanding. Many of these techniques produce longer scars or scars that curve around toward the back, which some patients find equally undesirable. Others add operative time or complexity. There is no single best method; the right choice depends on the patient’s body type, the volume of tissue being removed, and the surgeon’s experience with each approach. The point is that prevention is possible, and a surgeon who routinely addresses the lateral chest wall is less likely to leave a dog ear behind.

When Dog Ears Resolve on Their Own

Not every dog ear requires a second trip to the operating room. For smaller bulges, time and the body’s natural wound remodeling can do the work. A study tracking 140 dog ears over six months found that about four out of five resolved completely without intervention. The key predictors were size and patient demographics: dog ears under about 4 millimeters on the trunk were the most likely to flatten on their own, and younger patients and women showed the most regression.¹

Based on this evidence, a management algorithm has been proposed. For dog ears under about 8 millimeters, observation is the recommended first step. For those between 8 and 15 millimeters that are unlikely to resolve spontaneously, suture techniques that pleat the excess tissue toward the center of the wound can help flatten things without additional incisions. Once a dog ear exceeds about 15 millimeters, or if conservative and suture approaches fail, surgical excision becomes the standard recommendation.¹ This tiered approach saves many patients from unnecessary revision surgery while flagging the cases that genuinely need it.

Revision Surgery for Persistent Dog Ears

When a dog ear persists and bothers the patient, the fix is usually a minor outpatient procedure done under local anesthesia. The surgeon removes a small wedge of excess skin and fat, reshapes the contour, and closes the wound so the scar lies along a natural skin fold or tension line. One described technique uses a 90-degree incision angle to reposition the resulting scar into a less visible orientation, reducing both the bulge and the visual footprint of the correction.¹¹

Other correction methods go beyond simple excision. A study of lateral chest wall deformities found that when these were identified and addressed surgically, the approaches included transferring the patient’s own tissue from a nearby area, injecting fat for contouring, performing liposuction to reduce volume, or directly cutting out the excess. About 40 percent of patients in that study who had identifiable lateral deformities opted for surgical correction.² The choice among these options depends on whether the issue is mainly excess skin, excess fat, or both, and whether the patient wants to avoid additional visible scarring.

Recovery from a dog-ear revision is generally much lighter than from the original mastectomy. The procedure takes less than an hour in most cases, and patients typically return to normal activities within a week or two. The scar will be slightly longer than before, which is the primary aesthetic trade-off, but patients who pursue revision overwhelmingly report that the smoother contour is worth the added scar length.

The Conversation That Often Does Not Happen

A recurring finding across the literature is that patients frequently feel blindsided by dog ears because the possibility was never raised before surgery. Research on patient engagement in breast cancer care has emphasized the importance of shared decision-making and comprehensive preoperative education so that patients are well-informed about what their chest will actually look like after mastectomy.¹² When that conversation is missing, the patient may interpret a dog ear as a surgical error rather than a known and manageable outcome.

A scoping review of aesthetic flat closure specifically highlighted that one of the most important steps in surgical counseling is understanding the patient’s goals and setting realistic expectations through conversation and visual examples. Patients need to know that revisions are a possibility, and that a flat closure does not always mean perfectly smooth on the first attempt. The review also noted that predicting how a patient will look and feel without breasts was a key factor in patients’ own decision-making about whether to pursue reconstruction.¹³

If you are facing a mastectomy and plan to go flat, asking your surgeon directly about dog ears is reasonable and important. Specific questions worth raising include whether your body type puts you at higher risk, what incision design the surgeon plans to use to minimize lateral excess, and what the plan would be if a dog ear develops. A surgeon who takes the lateral chest wall seriously as an aesthetic concern, rather than treating it as an afterthought, is more likely to deliver a result that matches your expectations.

Dog Ears Versus Swelling

One of the most common sources of confusion in the weeks after mastectomy is telling the difference between a dog ear and normal postoperative swelling. Swelling after mastectomy, including seromas (fluid collections beneath the skin), can temporarily create bulges that look similar to dog ears. The distinction matters because swelling resolves on its own or with drainage, while a true dog ear is a structural issue that will not go away with time alone if it exceeds a certain size.

The clearest way to tell the difference is by feel and timing. Swelling tends to be soft, fluctuant, and diffuse, and it decreases over weeks to months. A dog ear feels more like a firm fold of skin pinched together, and its shape stays consistent as surrounding swelling goes down. Patients have reported being told by their care team that a lateral bulge was “just swelling” that would resolve, only to find months later that it was structural excess tissue all along. If a visible bulge at the scar’s end persists beyond three to four months and has a distinct fold or ridge to it, it is worth raising with your surgeon rather than continuing to wait.

Liposuction as a Standalone Fix

For dog ears where fatty tissue is the primary contributor rather than excess skin, liposuction alone can sometimes smooth the contour without any incision beyond the small cannula entry point. This is most useful for the lateral chest wall, where a thick pad of fat can persist even after mastectomy. The Paris Breast Center technique, for instance, pairs the mastectomy incision design with lipoaspiration of the lateral zone, removing an average of 450 milliliters of aspirate from the lateral chest wall to prevent dog ear formation in the first place.⁴

When used as a revision procedure after a dog ear has already formed, liposuction can reduce volume in the bulging area and allow the overlying skin to settle more smoothly. It works best in patients whose skin has enough elasticity to contract over the reduced volume. In patients with significant skin excess or poor skin quality, liposuction alone may leave behind loose, draping skin, and a direct excision becomes the better option. A plastic surgeon can usually assess which approach fits by examining the tissue quality at a consult.

Insurance and Access

Revision of a post-mastectomy dog ear is generally covered by insurance in the United States under federal law. The Women’s Health and Cancer Rights Act requires group health plans that cover mastectomy to also cover surgery to address all stages of reconstruction and physical complications of mastectomy, including contour irregularities. In practice, however, patients report variable experiences with coverage. Some insurers classify dog-ear revision as a cosmetic procedure, requiring appeals or additional documentation from the surgeon affirming that the bulge causes physical symptoms like chafing, pain, or difficulty with prosthetic wear. Having your surgeon document physical complaints, not just aesthetic dissatisfaction, strengthens a coverage claim.

For patients without reconstruction coverage or in health systems where access to plastic surgery is limited, the wait for revision can stretch to months or longer. This is especially frustrating for patients who were never told to expect a dog ear and who now face an additional bureaucratic process to fix a problem they feel should not exist. Advocacy groups focused on aesthetic flat closure have been working to raise awareness among surgeons and insurers alike that the lateral chest wall deserves the same surgical attention as the central mastectomy site, rather than being treated as an optional cosmetic refinement.

1
PubMed Central. A Systematic Review of Cutaneous Dog Ear Deformity: A Management Algorithm
2
Plastic & Reconstructive Surgery. The Lateral Chest Wall: A Separate Aesthetic Unit in Breast Surgery
3
PubMed Central. The Modified M-plasty Approach to Mastectomy: Avoiding the Lateral Dog-ear
4
ScienceDirect. Avoiding post mastectomy lateral “Dog Ears” by an L incision and lipoaspiration: The Paris Breast Center technique
5
PubMed Central. Insights Into ‘Living Flat’: A Qualitative Study of Patients Who Have Mastectomy Without Reconstruction
6
ScienceDirect. Advocating for Enhanced Patient Engagement in Breast Cancer Care: Impact of Residual Increased Lateral Adiposity and Consideration of the Pursuit of “Living Flat”
7
PubMed. Exploring Body Image Satisfaction in Post-Mastectomy Female Breast Cancer Patients
8
PubMed. Aesthetic Flat Closure Following Mastectomy: A Systematic Review of Techniques, Outcomes, and Patient Perspectives
9
PubMed. Surgical techniques to avoid lateral dog ear of the mastectomy scar: A systematic review
10
PubMed Central. The 5 D’s to Dunk the Dog: A Retrospective Clinical Review to Prevent Dog-Ear Contour Abnormalities in Vertical Breast Reductions and Breast Lifts
11
PubMed Central. Aesthetic refinement of the dog ear correction: the 90° incision technique and review of the literature
12
Clinical Breast Cancer. Advocating for Enhanced Patient Engagement in Breast Cancer Care: Impact of Residual Increased Lateral Adiposity and Consideration of the Pursuit of “Living Flat”
13
JPRAS Open. Evaluation of aesthetic flat closure: A scoping review