Congenital cancer refers to a rare diagnosis of cancer in a baby, either before birth or very shortly thereafter. This involves abnormal cells growing and dividing uncontrollably while the baby is still in the womb or immediately following delivery. While cancer is generally uncommon in children, its presence at birth is particularly infrequent, affecting approximately 1 in 10,000 babies born. Its early occurrence involves distinct biological mechanisms compared to cancers diagnosed later in childhood.
Genetic Origins
The primary mechanisms leading to congenital cancer involve alterations in a baby’s genetic material. These genetic changes can be inherited from parents, known as germline mutations. Such inherited mutations can predispose a baby to developing cancer by affecting genes that regulate cell growth and division. For instance, a mutation in a tumor suppressor gene, which normally helps prevent uncontrolled cell growth, could be passed down, increasing the likelihood of tumor formation.
Alternatively, genetic changes can arise spontaneously during fetal development, referred to as sporadic or de novo mutations. These new mutations occur in the developing cells of the embryo or fetus. They can affect genes that control cell proliferation and differentiation, such as proto-oncogenes. When a proto-oncogene mutates, it can become an oncogene, driving cells to grow and divide without proper regulation.
The precise timing and location of these mutations during fetal development influence the type and characteristics of the resulting tumor. For example, mutations occurring early in embryonic development might lead to widespread cellular abnormalities, while those later in gestation could result in more localized tumors. These genetic errors disrupt the delicate balance of cell growth and death, allowing abnormal cells to multiply and form a cancerous mass within the developing baby.
Maternal Transmission
A less common pathway for congenital cancer involves the direct transmission of cancer cells from the mother to the fetus across the placenta. The placenta typically acts as a protective barrier, preventing most substances and cells from passing between the maternal and fetal bloodstreams. However, in exceptionally rare instances, malignant cells from certain aggressive maternal cancers can breach this barrier.
This phenomenon is most often observed with maternal melanomas and some leukemias. If these cells manage to cross the placental barrier, they can then implant and grow within the fetal tissues. The baby’s immune system, which is still developing, may not recognize or effectively eliminate these foreign cancer cells, allowing them to establish a tumor. Such cases are exceedingly rare, with only a few dozen documented instances worldwide.
Common Types of Congenital Cancer
Several types of cancer are more frequently observed in newborns:
Neuroblastoma is the most common type of cancer diagnosed in infants, often originating from immature nerve cells in the adrenal glands or along the spine. These tumors can sometimes be detected as abdominal masses.
Congenital leukemia, particularly acute myeloid leukemia (AML), involves the abnormal proliferation of immature white blood cells in the bone marrow and can affect blood production throughout the body.
Retinoblastoma, a cancer of the retina in the eye, can also be congenital, stemming from mutations in specific genes that regulate retinal cell development. It often presents as a white pupil or strabismus.
Teratomas are tumors composed of different types of tissue, found at birth. These tumors arise from germ cells, which are cells with the potential to develop into any type of tissue, and can occur in various locations, including the sacrococcygeal region or gonads.
Early Detection
The discovery of congenital cancer often occurs through prenatal screenings or shortly after birth. Advanced imaging techniques, such as prenatal ultrasound or fetal MRI, can sometimes identify unusual masses or growths within the developing fetus during routine check-ups. These findings may prompt further investigation and specialized fetal care.
Following birth, signs of congenital cancer can vary depending on the tumor’s location and size. Some babies may present with palpable lumps, swelling, or unexplained symptoms like difficulty feeding, breathing problems, or unusual skin discoloration. Once a suspicious mass or symptom is identified, diagnostic procedures are initiated. These typically involve additional imaging studies, such as MRI, CT scans, or ultrasound, to better visualize the tumor. A biopsy, where a small tissue sample is taken for microscopic examination, is often performed to confirm the diagnosis and determine the specific type of cancer.