Poland Syndrome

Overview

Poland syndrome is a rare condition present at birth in which the chest muscles on one side of the body are underdeveloped or absent. The most consistent feature is the absence or underdevelopment of part of the pectoralis major, the large muscle of the chest. The condition almost always affects just one side of the body, and the right side is involved more often than the left.

The severity of Poland syndrome varies widely. Some people have only a subtle difference in the chest that is barely noticeable, while others have more pronounced changes that may also involve the hand, fingers, breast, ribs, or other tissues on the same side. The condition is usually not life-threatening and most people lead healthy, active lives. Treatment, when desired, focuses on appearance and, in some cases, function.

Symptoms

Features of Poland syndrome occur on one side of the body and vary in degree:

• Absence or underdevelopment of part of the chest (pectoral) muscle
• A sunken or uneven appearance of the chest on the affected side
• Underdevelopment or absence of the breast and nipple on that side, which may be more noticeable after puberty in women
• Differences in the hand on the same side, such as shorter or webbed fingers
• Sparse underarm hair or changes in the ribs or shoulder blade in some cases

Many people have mild features and few or no functional limitations.

Causes

The exact cause of Poland syndrome is not known. The leading explanation is that during early development before birth, there is a temporary reduction in blood flow to the developing chest and arm on one side, which affects how those tissues form. This would explain why the features are usually limited to one side of the body.

In the great majority of cases, Poland syndrome occurs by chance in a person with no family history, and it is not inherited. It is not caused by anything the parents did during pregnancy, and it cannot be passed from person to person.

Risk Factors

• The condition is generally sporadic, meaning it occurs randomly without identifiable risk factors
• It is more common in males than females
• The right side of the body is affected more often than the left

Because it is not usually inherited, having Poland syndrome does not mean a person's children are likely to have it.

Diagnosis

Poland syndrome is usually diagnosed by examination, often in infancy or childhood, though mild cases may be noticed later:

• Physical examination: Identifying the missing or underdeveloped chest muscle and any hand or breast differences on the same side.
• Imaging: X-rays, CT, or MRI to assess the muscles, ribs, and underlying structures.
• Evaluation of the hand: When finger or hand differences are present.

Imaging also helps plan treatment if surgery is being considered.

Treatment

Treatment depends on how much the condition affects appearance and function, and many people need no treatment at all:

• Observation: For mild cases that do not cause functional or significant cosmetic concerns.
• Reconstructive surgery: To improve the appearance and contour of the chest, such as transferring muscle or using an implant, often considered after the body has matured.
• Breast reconstruction: For women with breast underdevelopment on the affected side, to improve symmetry.
• Hand surgery: When finger or hand differences affect function or appearance.

A team of specialists, which may include plastic and hand surgeons, helps tailor the plan.

Prevention

Poland syndrome cannot be prevented because it develops before birth and its cause is not understood. It generally occurs by chance and is not linked to anything done during pregnancy. Care focuses on monitoring development and addressing appearance or function if and when a person wishes to.

When to See a Doctor

See a doctor if you notice that a child has uneven chest development, a missing chest muscle, or differences in one hand, so the features can be evaluated and any functional needs addressed. Older children and adults may wish to consult a specialist if the appearance of the chest or breast causes concern, or to discuss reconstructive options. Poland syndrome itself is usually not dangerous, but evaluation can confirm the diagnosis and guide any desired treatment.

Related Topics

Frequently Asked Questions

References

1. National Organization for Rare Disorders (NORD). Poland Syndrome.
2. Genetic and Rare Diseases Information Center (GARD). Poland syndrome.
3. MedlinePlus, U.S. National Library of Medicine. Poland syndrome.
4. American Society of Plastic Surgeons (ASPS). Chest wall reconstruction.