Poland Syndrome

Patrick J. Buchanan

Paul S. Cederna

ANATOMY

There are two predominant variations of Poland syndrome: simple form (mild) and complex form (severe).
The simple form is the most common and is characterized by the absence of the sternocostal head of the pectoralis major muscle and effacement of the ipsilateral axillary fold.
- The clavicular head of the pectoralis major muscle remains as a thin triangular muscle bundle that attaches the humerus to the inferomedial third of the clavicle.
- The ipsilateral breast is hypoplastic or aplastic.
- The ipsilateral nipple-areolar complex is typically smaller in diameter and displaced laterally and superiorly toward the axilla (FIG 1).
The complex form is characterized by the absence of the sternocostal head of the pectoralis major muscle, ipsilateral rib and/or sternal hypoplasia or absence, and other ipsilateral muscular abnormalities (FIG 2).
- The clavicular head of the pectoralis major muscle may be diminutive.
- The ipsilateral latissimus dorsi, trapezius, pectoralis minor, serratus anterior, external oblique, and/or rectus abdominis muscles may be abnormal.
  - The pectoralis minor muscle is commonly hypertrophic.
  - Absence of the serratus anterior muscle results in a winged scapula.
  - Insertion of the ipsilateral rectus abdominis muscle is displaced cranially.
- The sternum is foreshortened and bifid with a pectus excavatum appearance.
- The ipsilateral scapula is small and cranially displaced, causing an internal shoulder rotation when compared to the contralateral side.
- The ipsilateral anterior second through fifth ribs are thin, short, and devoid of their superolateral cartilage.

FIG 1 • Simple form of Poland syndrome depicting an ipsilateral breast anomaly with a smaller and superolaterally displaced nipple-areolar complex.

FIG 2 • Complex form of Poland syndrome showing ipsilateral axillary webbing, ipsilateral rib and sternal hypoplasia, ipsilateral trapezius, serratus anterior, rectus abdominis, and external oblique muscle abnormalities.

PATHOGENESIS

To date, no definitive cause of Poland syndrome has been elucidated.
However, there are theories identifying developmental and familial causes.
- Developmentally, in the 6th week of gestation, there is an interruption of the subclavicular arterial branches causing maldevelopment of the tissues supplied by these vascular pedicles
- Currently, geneticists believe Poland syndrome is rarely inherited; however, there is documentation of a 1% inheritance pattern from affected individuals.

NATURAL HISTORY

The true incidence and etiology of Poland syndrome still remains unknown; however, it tends to occur more on the right side, 2 to 3:1, is more common in males, 2:1, and is estimated to occur 1 in 20 000 to 30 000 live births.³
The most common presentation is that of a patient with a unilateral absence of the sternocostal head of the pectoralis major muscle with hypoplastic or absent breast parenchyma.¹
The vast majority of patients with Poland syndrome present with concerns about the shape and appearance of their chest or abnormal breast development.¹

PATIENT HISTORY AND PHYSICAL FINDINGS

The surgeon must be acutely aware of the social impact of Poland syndrome on the patient and their parents.
Patients with the simple form of Poland syndrome may be aware of their abnormality earlier than their family, as it can remain unannounced until early adolescence, as muscle and breast development occur.
- Early in childhood, parents may notice a slight chest asymmetry.
- Adolescent children with Poland syndrome spend an inordinate amount of time trying to conceal their asymmetry from their parents and others.
The severe form, on the contrary, is readily known during infancy by the parents, as the chest wall is grossly asymmetric.
In all patients, there will be a noticeable soft tissue deficiency of the affected side of the chest due to volume loss from the partial or complete absence of the pectoralis musculature.
- The noticeable asymmetry often leads to adverse psychosocial sequelae.
- Patients often report an adverse impact on their social functioning, emotional well-being, and psychological health.

IMAGING

Diagnostic imaging is available but usually not necessary in cases other than the most severe variants.
- Ultrasonography will show an absence of a portion of the pectoralis major muscle and asymmetry of the rib cage.⁴
- Mammography is typically not used as an imaging modality for Poland syndrome; however, absence of the pectoralis major muscle can be incidentally discovered on the mediolateral oblique view of a hypoplastic breast.⁴
- A CT scan can be used for presurgical planning to confirm the presence of the latissimus dorsi muscle and to better define the structural chest wall deformity.⁵
- MRI may be useful to better define the patient’s anatomy as it offers a multiplanar view without the ionizing radiation of a CT scan.⁵
- Both color-coded duplex sonography and contrastenhanced magnetic resonance angiography allow for the evaluation of selected arteries and vessels.⁵

NONOPERATIVE MANAGEMENT

Because reconstruction is rarely ever performed to restore a severe functional deficit, providing reassurance to the patient and their family is an important aspect of care that should not be overlooked by the surgeon.
Removable external breast prostheses help correct the appearance of a female patient’s chest and breast in clothing.

SURGICAL MANAGEMENT

The reconstructive options for patients presenting with chest wall deformities from Poland syndrome depend on several key factors, including anatomical severity, gender, patient preferences, and associated anomalies.
The timing and number of reconstructive stages is also of paramount importance.
- A tissue expander can be placed early to gradually expand the affected side to decrease the amount of noticeable asymmetry as the contralateral breast developmentally matures.
- Fat grafting can be initiated early to camouflage the asymmetry until the definitive reconstructive procedures are performed.
Tissue expander-based reconstruction is ideal for the female patient with a hypoplastic and fibrotic breast or a patient with an aplastic breast.
The latissimus dorsi muscle transfer can be used with any of the reconstructive approaches.
- It is the best method to reconstruct the anterior axillary fold.
- It can be performed on any patients, male or female, with a robust latissimus dorsi muscle.
- The surgeon should discuss with the patients that harvesting of the latissimus dorsi muscle can create asymmetry in their back.
Customized chest wall implants may be adjunctively needed in women and are often the treatment of choice in men.⁶
- Author preference is for a custom silicone chest wall prosthesis.
- The advantages of the customized chest wall implant reside in its ease of fabrication and insertion.
  - There is a relatively low morbidity for this technique compared to flap reconstruction.⁶
- Disadvantages include implant migration, contour irregularities, patient reported discomfort, and potentially palpable or visible edges.⁶
The endoscopic approach is typically performed in two stages when using a tissue expander and latissimus dorsi muscle transfer