Poland syndrome is a rare disorder of multifactorial origin. Unilateral hypoplasia of the thorax, mainly in the form of pectoralis muscle deficiency and ipsilateral upper limb abnormalities of varying degrees are clinical hallmarks. The diagnosis is made clinically and surgery is performed to correct and stabilize the affected anatomical structures.
The clinical presentation consists of two principal components - thoracic and upper limb abnormalities (TA and ULA, respectively) . Subtle hypoplasia on the breast and ribs, underdevelopment of the pectoralis muscle, scoliosis, chest wall depression, absence of axillary hair and limited subcutaneous fat are some of the most common TA, whereas syndactyly, brachydactyly and hypoplasia or aplasia of the middle phalanges are notable ULAs  . Deficiency of sweat glands and skin over the affected areas is also reported .
The diagnosis is made clinically, but because the presentation may significantly vary from patient to patient, a thorough physical examination to assess the extent of the abnormalities is vital. Adjuvant imaging or laboratory procedures should be performed when a clinical suspicion toward a malignant disease is made .
Various surgical procedure have been performed in these patients, depending on the anomalies that are present. Bone grafts or a prosthetic mesh can be used to reconstruct or stabilize the aplastic ribs, whereas breast implants or muscle flaps can be used for breast hypoplasia or muscle deficiency . In any case, surgery and proper rehabilitation is the principal method for patients suffering from Poland syndrome.
The condition itself does not pose a risk for the patient and surgical treatment may provide some benefit, but case reports have associated Poland syndrome with several malignancies, including leukemia and carcinoma of the hypoplastic breast, which is why a detailed approach to individuals suffering from this syndrome is necessary .
A genetic background involving autosomal dominant, autosomal recessive and autosomal dominant with incomplete penetrance mutations has been described, but the principal cause is presumed to be obstruction of blood flow through the subclavian artery during embryogenesis and the trigger of such events is yet to be discovered  . The effects of environmental stimuli (teratogenic drugs and tobacco) have also been proposed, suggesting a multifactorial model of disease in Poland syndrome .
Poland syndrome is considered to be a rare disease, with estimated incidence rates of 1 in 30,000-32,000 live births and a significant predilection toward male gender is observed (male-to-female ratio of 2-3:1) . Risk factors haven't been established so far, but some studies have confirmed an increased risk for women who smoked during pregnancy .
The pathogenesis model remains to be solidified, but some form of vascular insult during embryogenesis is proposed to be the principal mechanism of disease . Namely, studies have proposed that blood supply through the subclavian or vertebral arteries is disrupted during the 6th week of gestation, leading to variable defects of areas with restricted blood flow .
Current prevention strategies are unknown, due to the incomplete understanding of the etiology of the syndrome.
Initially described more than 200 years ago by Alfred Poland , Poland syndrome is a rare congenital disorder with unilateral hypoplasia of the chest wall and ipsilateral abnormalities of the hand as its constitutive features . The exact cause remains unknown, but a multifactorial model involving genetic, environmental and embryologic factors have been proposed . Poland syndrome appears in approximately 1 in 30,000 live births, with a strong predilection toward males . The clinical presentation is characterized by unilateral thoracic abnormalities (pectoralis muscle deficiency, hypoplasia of the chest wall, ribs and breast) and ipsilateral upper limb deficits (syndactyly, brachydactyly, variable degrees of finger webbing, and either hypoplasia or aplasia of the middle phalanges) . The diagnosis is made based on clinical findings and determination of other anomalies that have been associated with this syndrome, such as renal or cardiac disease, but also malignant cancers of the hematopoietic lineage . Surgical treatment to correct the present anomaly is the recommended treatment modality .
Poland syndrome is a rare disorder that occurs during pregnancy and is distinguished by the appearance of deformities of the chest and the arm on only one side of the body in newborns and children. The exact cause of this congenital disorder remains unknown, but the most probable theory proposes restriction of blood flow to those areas by poorly understood mechanisms during embryonic life. Although most cases develop sporadically, some reports have identified genetic mutations and a familial occurrence, suggesting a genetic component in this syndrome as well. Poland syndrome appears in approximately 1 per 30,000 live births and it is more frequently seen in males. Most common symptoms are underdevelopment of the pectoralis muscle, the breast and the ribs when discussing abnormalities of the thorax, whereas various abnormalities of fingers, as well as deficiency of the skin, subcutaneous tissue and hair in the armpit and the upper arm are seen as well. Because the clinical presentation can significantly vary from patient to patient, it is imperative to conduct a meticulous physical examination to determine the extent of pathological changes and thus decide on optimal therapy. Surgical repair and/or correction of the identified anomalies is usually performed. Poland syndrome is a self-limiting disorder that requires therapy principally for cosmetic reasons, but some cases have been associated with more serious diseases, including lymphomas and carcinoma of the underdeveloped breast, which is why an early diagnosis is necessary.