People can indeed be born without nipples, a condition that represents a rare congenital anomaly. This unusual occurrence stems from variations in development before birth.
Is It Possible?
Athelia is the medical term for being born without one or both nipples. It is defined as the absence of the nipple, which often includes the areola, the pigmented area surrounding it. Athelia can occur by itself, affecting only the nipple, or it can be observed as one feature among a broader set of developmental variations.
This differs from amastia, a more extensive condition where both the nipple and the entire breast tissue are absent. Amastia can affect one or both sides of the body. In some instances, amastia may involve the absence of breast tissue while the nipple is present, a condition known as amazia.
How It Develops
The formation of nipples and mammary glands begins early in embryonic development, specifically around the sixth week of gestation. This process starts with “milk lines,” ridges of ectodermal tissue, the outermost embryonic layer, extending along the ventral surface of the embryo. These lines give rise to mammary buds, initial invaginations of the surface ectoderm into the underlying mesenchyme.
As development progresses, these buds elongate and branch, forming a rudimentary duct system by birth. The skin overlying this developing mammary tissue remodels to form the nipple structure, involving a thickening of the epidermis and the invagination of keratinocytes. Disruptions to these intricate processes, particularly between the sixth and eighth weeks of gestation, can lead to the absence of nipple formation. Such disruptions can result from genetic mutations affecting the proper development of epithelial cells or signaling pathways, or they can be due to sporadic errors in development. In many instances, the precise reason for the developmental failure remains unknown.
Conditions Linked to Missing Nipples
While athelia can sometimes occur as an isolated finding, it is frequently associated with broader genetic syndromes or congenital anomalies. One notable condition is Poland syndrome, which typically involves underdevelopment or absence of chest wall muscles on one side of the body. In individuals with Poland syndrome, the absence of a nipple is often accompanied by an underdeveloped or absent breast and underlying chest muscles on the same side. This syndrome is thought to arise from problems with blood flow during early development in the womb.
Athelia can also be a feature of ectodermal dysplasias, a diverse group of over 180 genetic syndromes affecting the development of skin, hair, teeth, and sweat glands. In these conditions, athelia occurs because the ectodermal layer does not develop properly. Other rare syndromes, such as progeria syndrome, Yunis-Varon syndrome, and scalp-ear-nipple syndrome, also list athelia among their symptoms. In these cases, the missing nipples are usually just one of several symptoms that collectively characterize the specific syndrome.
Occurrence and Medical Considerations
Athelia is considered a rare condition, whether it occurs in isolation or as part of a syndrome. When athelia is the only anomaly present, it is generally viewed as a benign cosmetic variation that does not typically pose significant health problems or affect overall health or lifespan.
Medical evaluation is typically recommended if other symptoms are present alongside athelia, as this could suggest an underlying syndrome requiring further investigation. Diagnosis is usually made at birth through physical examination. Imaging studies, such as ultrasound or MRI, may be utilized to assess the presence and development of underlying breast tissue or to identify any associated anomalies. For individuals concerned about the cosmetic appearance, reconstruction options may be considered later in life.