Blastoma – Embryonal Tumor

The term blastoma is derived from the Greek word “blastos”, which translates to germ or sprout. It refers to tumors that originate from embryonal or fetal precursor cells – meaning from cells that have not yet fully developed into a specific tissue type. These immature cells can grow uncontrollably and form malignant tumors.

Blastomas typically develop in early childhood because many embryonal cells are still present during this phase of life, actively dividing and differentiating. As a person ages, these precursor cells disappear, which is why blastomas are significantly rarer in adults. They account for a substantial proportion of all childhood cancers and rank alongside leukemias and lymphomas as the most common pediatric tumor diseases.

Blastomas are almost always malignant. Benign variants exist but are rare. However, malignancy does not necessarily mean a poor prognosis – many blastomas respond very well to chemotherapy, which distinguishes them from many other types of cancer.

The terms blastoma and embryonal tumor are frequently used synonymously in everyday clinical practice, but they do not describe exactly the same thing. Blastoma is a histological term that indicates the origin from embryonal tissue and usually appears in the name of the tumor – such as neuroblastoma, nephroblastoma, or retinoblastoma. Embryonal tumor is an overriding clinical term that encompasses all tumors arising from embryonal cells, regardless of whether they carry the suffix “-blastoma”.

A specific entity within embryonal tumors is the embryonal tumor with multilayered rosettes, abbreviated as ETMR. It is very rare, affects almost exclusively toddlers under three years of age, and originates in the brain. Despite intensive therapy, its prognosis is unfavorable. In recent years, molecular genetic diagnostics have contributed to differentiating it more precisely from other embryonal brain tumors.

Blastomas are classified according to their organ of origin. Each subtype has its own biological profile, specific symptoms, and therapeutic approaches. The four most common and clinically significant blastomas are medulloblastoma, nephroblastoma, neuroblastoma, and retinoblastoma.

Blastomas of the brain develop from embryonal nerve cells and affect almost exclusively children and adolescents. They grow rapidly and require intensive combination therapy.

Medulloblastoma: the most common malignant brain tumor in childhood, originates in the cerebellum and is today divided into different subgroups based on molecular genetics. With modern therapy, certain risk groups achieve five-year survival rates of over 80 percent.

Kidney blastomas originate from embryonal kidney tissue and are the most common kidney tumors in childhood. They often become noticeable through a palpable swelling in the abdomen.

Nephroblastoma: also known as Wilms’ tumor, it is the most common kidney tumor in children and usually occurs between the second and fifth year of life. The recovery rates are very good with modern therapy and exceed 90 percent in early stages.

Neuroblastomas develop from immature cells of the sympathetic nervous system and are the most common extracranial solid tumor in infancy and early childhood. Their behavior is exceptionally variable – ranging from spontaneous regression to a highly aggressive course.

Neuroblastoma: usually originates in the adrenal gland or along the spine, but can also occur in the neck, chest, or abdomen. Infants often have a significantly better prognosis than older children, as favorable biological variants occur more frequently in them.

Eye blastomas develop from embryonal retinal cells and affect almost exclusively toddlers. They are the most common intraocular tumor in childhood and are curable in many cases if detected early.

Retinoblastoma: originates in the retina of the eye and usually manifests before the fifth year of life. It can occur unilaterally or bilaterally, with the bilateral form frequently being hereditary. The first sign is often a whitish light reflex in the pupil, which becomes noticeable in photographs.

In addition to the four primary forms, there are other, rarer blastomas. Hepatoblastoma develops in the liver and is the most common primary liver tumor in childhood – it usually manifests before the third year of life and responds well to chemotherapy. Pleuropulmonary blastoma originates in the lungs or pleura and is a very rare tumor of early childhood with three biologically distinct types. Pancreatoblastoma is the most common pancreatic tumor in children, likewise rare, but often surgically curable in early stages.

Blastomas are primarily diseases of childhood, but they can occur in rare cases in adults as well. Nephroblastoma in adults is the most well-known exception – it often behaves more aggressively in adults than in children and is frequently diagnosed only at an advanced stage, since it is less expected. Medulloblastoma can also occur in young adults, with certain molecular subgroups preferentially affecting adult patients.

When a blastoma is diagnosed in an adult, treatment should take place in a specialized center with experience in treating these rare tumors, as therapeutic protocols from pediatrics are not always directly transferable.

The symptoms of blastomas depend heavily on their location. A common feature of many forms is that they cause barely any complaints in the early stages and often become noticeable only through an incidental finding or a palpable change.

Parents and pediatricians should be alert to the following signs: a newly occurred, growing, palpable, and painless swelling in the abdomen, back, or neck; a whitish or yellowish light reflex in the pupil in photographs; newly occurred visual disturbances or a squint; persistent headaches, vomiting, or balance disorders; as well as unexplained fatigue, paleness, or weight loss. None of these signs are specific to a blastoma, but a pediatrician should be consulted promptly if symptoms persist or increase.

In medulloblastoma, balance disorders, coordination problems, and headaches due to increased intracranial pressure are paramount. Nephroblastoma usually becomes noticeable through a palpable swelling in the abdomen, which is often discovered by chance during bathing or dressing. Neuroblastoma can cause very diverse symptoms depending on its location – ranging from abdominal pain and shortness of breath to bone pain in the presence of metastases. Retinoblastoma is frequently detected by the characteristic whitish pupil reflex in photographs, which is caused by the tumor tissue behind the lens.

The diagnosis of a blastoma requires several examination steps and should take place in a pediatric oncological center. Imaging techniques such as ultrasound, MRI, and CT are the primary diagnostic tools and provide indications regarding the size, location, and extent of the tumor.

Tumor markers in the blood play a varying role depending on the tumor type. In neuroblastoma, catecholamines and their metabolites in the urine are important diagnostic markers. In hepatoblastoma, AFP (alpha-fetoprotein) is severely elevated. In medulloblastoma and retinoblastoma, tumor markers are less relevant, making imaging all the more crucial.

The final diagnosis is established through histological examination of tumor tissue. In retinoblastoma, a biopsy is typically avoided because the risk of tumor cell seeding is too great – here, the diagnosis is made clinically and via imaging. Molecular genetic analyses are standard today for all blastomas, as they are decisive for risk classification and treatment planning. In retinoblastoma, a genetic examination of the family is also important, since the hereditary form increases the risk for siblings and offspring.

The treatment of blastomas is guided by tumor type, stage, the child’s age, and molecular genetic characteristics. It is planned within an interdisciplinary pediatric oncological team and should be carried out in a specialized center.

Surgical removal of the tumor is a central treatment step for most blastomas. In nephroblastoma, a preoperative chemotherapy is frequently performed in Europe to shrink the tumor and facilitate surgery. In neuroblastoma, the surgical approach depends heavily on the stage and location.

Chemotherapy plays a central role in virtually all blastomas. Many blastomas are chemosensitive, meaning they respond well to cytostatic drugs. Radiation therapy is deployed depending on the tumor type and the child’s age – in very young children, it is avoided or minimized whenever possible, as it can have long-term impacts on development. In retinoblastoma, local therapeutic procedures such as intra-arterial chemotherapy or laser treatment are also utilized to preserve the eyeball.

Blastomas are treated with intensive chemotherapy protocols, surgeries, and sometimes radiation therapy. The side effects of these therapies – pronounced nausea, mucosal damage, and susceptibility to infection – can be substantial and require targeted supportive care. Since blastomas predominantly affect children, we emphasize that close coordination with the treating pediatric oncological team is strictly mandatory for the integrative support of young patients. We provide individual and integrative support for adult patients with a blastoma – naturally also in consultation with the oncological treatment team.

In adult patients, acupuncture can be used supportively for chemotherapy-induced nausea and pain. To strengthen general well-being, an individually adjusted mistletoe therapy as well as selected measures of phytotherapy can contribute to improving the tolerability of standard therapy.

Many chemotherapeutic agents used for blastomas unfold their efficacy by generating oxidative stress in tumor cells. Restorative measures such as infusion therapy with micronutrients or a mitochondrial therapy are therefore only deployed after the completion of intensive treatment cycles to support the body during recovery without endangering the therapeutic effect. An intestinal cleanse can restore intestinal health and improve nutrient absorption following chemotherapy-induced mucosal damage – here too, the application is strictly synchronized with the treatment cycles.

An often underestimated but essential part of integrative support is psycho-oncological counseling – for those affected and their close circle. A severe cancer illness presents all involved parties with extraordinary emotional challenges that require professional support.

The prognosis for blastomas is overall significantly better than for many other cancer diseases – provided that diagnosis occurs early and treatment takes place in a specialized center. Many blastomas belong to the most highly treatable childhood cancers.

With modern therapeutic protocols, nephroblastoma achieves cure rates of over 90 percent in early stages. Retinoblastoma is curable in most cases, with the preservation of vision and the eyeball depending on the size and location of the tumor. Medulloblastoma achieves five-year survival rates of over 80 percent in certain risk groups. Neuroblastoma is the most variable in its prognosis – while infants with favorable variants have very good chances of recovery, the prognosis for older children with high-risk neuroblastoma remains significantly less favorable despite intensive therapy.

Long-term consequences of the therapy – for example, due to radiation or intensive chemotherapy – can affect the quality of life of the cured children. Regular follow-up examinations are therefore important not only for detecting recurrences, but also for the early identification and treatment of late effects.

Blastomas are rare diseases that raise many questions – especially when a child is affected. We have answered the most common questions here in an objective and easy-to-understand manner.

The information listed contains relevant topics and serves to improve understanding.