Baby boy born at full term via forceps-assisted vaginal delivery to a 17-year-old primigravida was noted to have left arm and chest anomalies. Apgar scores 9 at 1 minute and 9 at 5 minutes. No pregnancy complications except for low amniotic fluid index. Second trimester ultrasonogram showed no malformations. At birth, infant was vigorous. He tolerated feeding well and passed urine and stool appropriately. Results of a hearing screen and newborn metabolic screen were normal. No family history of genetic disorders.
Clinically, infant was asymptomatic. Vital signs normal. Weight, height, and head circumference (3.040 kg, 50.8 cm, and 33 cm, respectively) appropriate for gestational age. He had a flat left upper chest, an abnormal and caudally displaced left nipple, hypoplasia of the muscles of the upper left shoulder girdle and arm, significant shortening and bowing of the left forearm, and left hand cutaneous syndactyly. The left thumb resembled a finger and was not opposable. Heart sounds heard best to the right of midline, corresponding to dextroposition of the heart. No heart murmurs. Remaining physical findings unremarkable.
(Answer and discussion on next page)
ANSWER: POLAND SYNDROME
Poland syndrome, also known as Poland sequence, is a rare congenital anomaly characterized by unilateral chest wall hypoplasia and ipsilateral anomalies of the upper extremity. The condition, first described by Dr Alfred Poland in 1841, was officially named in 1962 by Dr Patrick Clarkson, who reported on 3affected children. The incidence of Poland syndrome is 1 per 20,000 to 30,000; however, it is believed to be underreported. The syndrome is 3 times more likely in males than in females; the right side is favored over the left.1
ETIOLOGY
Diminished blood supply to the affected side secondary to developmental defects of the subclavian artery is the suspected cause of Poland syndrome. Maternal drug abuse during pregnancy has been reported.2,3 Most cases of Poland syndrome arise sporadically. Familial cases have been described, which suggests some degree of genetic transmission. However, a case of Poland syndrome in one identical twin has been reported.4
CLINICAL MANIFESTATIONS
The minimum criterion needed for diagnosis is unilateral absence or hypoplasia of the sternal portion of the pectoralis major muscle. Other classic features on the ipsilateral side include:
•Hypoplasia or aplasia of the breast and nipple.
•Deficiency of subcutaneous fat and axillary hair.
•Abnormalities of the rib cage.
•Upper extremity anomalies, such as short arm and fingers as well as syndactyly.2
It is not rare for infants with Poland syndrome to have all the classic features. Intelligence is not impaired in children with this syndrome.
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| Figure 1 – The infant’s chest radiograph shows dextrocardia and a malformed left clavicle and scapula. |
ASSOCIATED CONDITIONS
Dextrocardia, without other cardiovascular defects, has been described in patients with left-sided anomalies (Figure 1).5,6 Eventration of the diaphragm has been reported with Poland syndrome(Figure 2).7 In this rare condition, the diaphragm is incompletely muscularized and is permanently elevated but retains its continuity and attachments to the costal margin. The presence of these associated anomalies is not expected to affect prognosis.
Poland syndrome can be associated with Möbius syndrome (congenital facial paralysis and limb reduction defects) and Klippel-Feil syndrome (fused cervical vertebrae), which are also thought to be secondary to subclavian artery disruption.8 Hematopoietic malignancies, breast cancer, and Wilms tumor have been described in patients with Poland syndrome.9,10
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| Figure 2 – This radiograph of the infant’s left chest and arm shows a hypoexpanded left lung with a domeshaped diaphragm, consistent with diaphragmatic eventration. Shortening of the ulna and bowing of the radius are apparent on the left side. |
TREATMENT AND OUTCOME
Affected children are seldom symptomatic and often require no immediate treatment. Mild formsof Poland syndrome can go unrecognized. Children with anomalies that impede normal function may benefit from physical therapy and/or surgical intervention. Reconstructive surgery is offered during teenage years for cosmetic reasons. Either existing chest muscles or transplanted muscles from another body area may be used to develop symmetry between the affected and unaffected side. Reconstruction of the rib cage can be provided at the same time. In adolescent girls, in order to ensure breast symmetry, reconstructive surgery is often postponed until breast development on the uninvolved side has been completed. Psychosocial treatment may be needed for those with poor body image or low self-esteem until surgery can be provided.
This infant was discharged home after evaluation by specialists in genetics, pediatric cardiology, hand surgery, and pediatric orthopedic surgery. No further genetic workup was deemed necessary. A chest CT scan confirmed the radiographic findings. Head and abdominal ultrasonographic findings were normal. Physical therapy was arranged and future surgical intervention was planned. At age 3 months, the infant was thriving; no other anomalies were noted.