Condition: Poland Syndrome

Poland Syndrome is a rare condition that is evident at birth (congenital). Associated features may be extremely variable from case to case. However, it is classically characterized by absence (aplasia) of chest wall muscles on one side of the body (unilateral) and abnormally short, webbed fingers (symbrachydactyly) of the hand on the same side (ipsilateral).

In those with the condition, there is typically unilateral absence of the pectoralis minor and the sternal or breastbone portion of the pectoralis major. The pectoralis minor is a thin, triangular muscle of the upper chest wall; the pectoralis major is a large, fanlike muscle that covers most of the upper, front part of the chest.

Affected individuals may have variable associated features, such as underdevelopment or absence of one nipple (including the darkened area around the nipple [areola]) and/or patchy absence of hair under the arm (axilla). In females, there may be underdevelopment or absence (aplasia) of one breast and underlying (subcutaneous) tissues. In some cases, associated skeletal abnormalities may also be present, such as underdevelopment or absence of upper ribs; elevation of the shoulder blade (Sprengel deformity); and/or shortening of the arm, with underdevelopment of the forearm bones (i.e., ulna and radius).

Poland Syndrome affects males more commonly than females and most frequently involves the right side of the body. The exact cause of the condition is unknown.