Unilateral flat chest wall in a child

Poland syndrome (PS) was first described by Alfred Poland in 1840.¹ PS is characterized by the unilateral absence of the pectoralis major muscle. Hypoplasia or aplasia of other muscles like serratus anterior, lattisimus dorsi and external oblique have also been described. PS is associated with other skeletal and visceral anomalies.^2,3 PS is usually unilateral, occurs more in males and is more commonly seen on the right side. Though the etiology of PS is unknown, it has been postulated to be due to an interruption of blood supply in the subclavian artery during the embryonic stage of development.⁴ The interruption in one or more branches of the subclavian artery leads to the associated anomalies. Bavinck and Weaver introduced the term “Subclavian Artery Supply Disruption Sequence” and common pathogenesis for Poland syndrome, Moebius syndrome and Klippel-Feil syndrome was proposed.⁴ The involvement of the breast in the syndrome ranges from mild hypomastia to amastia. The rib anomalies that are commonly observed were the absence of costal cartilages in 2, 3 or 4th ribs which can lead to herniation of the lung tissue. The skeletal abnormalities that were commonly reported include elevation of the shoulder blade (Sprengel deformity), shortening of the arm and/or forearm, brachydactyly and syndactyly.² Cardiac anomalies like dextrocardia are commonly associated when the left side was involved. Many malignancies were reported in patients with PS including leukemia, lymphoma, lung carcinoma, gastric carcinoma and head and neck tumors.⁵ In the present case, the absence of the pectoralis major muscle alone without any other abnormalities was observed. No surgical treatment was offered and the family was counseled.
The management of PS depends on the extent of anomalies and functional limitations. The Italian Association for Poland Syndrome has provided best practice recommendations for the management of patients with PS.⁶ The treatment of patients with PS is mainly done for aesthetic reasons. For chest deformity, silicon prosthesis is safely used.⁷ In females, the reconstruction of the breast will be advantageous. Corrections of other deformities, like syndactyly, are also indicated whenever possible. Also, children with PS should be given psychological support that will improve long-term outcomes.

References :

Poland A. Deficiency of the pectoral muscles. Guys Hosp Rep 6 (1841): 191-193. Fokin AA, Robicsek F. Poland syndrome revisited. Ann Thorac Surg. 2002;74:903-18. Urschell HC. Poland syndrome. Chest Surg Clin. North Am. 2000;10:393-403. Bavinch JNB, Weaver DD. Subclavian artery disruption sequence: hypothesis of vascular etiology for Poland, Klippel-Feil and Mobius anomalies. Am J Med Genet. 1986;23:903-18. Hashim EA, Quek BH, Chandran S. A narrative review of Poland's Syndrome: Theories of its Genesis, evolution and its diagnosis and treatment. Translational Pediatrics. 2021;10(4):1008-19. Baldelli I, Baccarani A, Barone C, Bedeschi F, Bianca S, Calabrese O, et al. Consensus based recommendations for diagnosis and medical management of Poland syndrome (sequence). Orphanet Journal of Rare Diseases. 2020;15(1). J. Taub P, Chavanon V, S. Taub J. Poland syndrome: Case report and discussion. Journal of Surgery. 2017;3(6).