Many patients first complain of pain that may be worse at night, may be intermittent and of varying intensity and may have been occurring for some time. Teenagers who are active in sports often complain of pain in the lower femur, or immediately below the knee. If the tumor is large, it can present as overt localised swelling. Sometimes a sudden fracture is the first symptom, because affected bone is not as strong as normal bone and may fracture abnormally with minor trauma. In cases of more deep-seated tumors that are not as close to the skin, such as those originating in the pelvis, localised swelling may not be apparent.

An osteosarcoma (OS) or osteogenic sarcoma (OGS) is a cancerous tumor in a bone. Specifically, it is an aggressive malignant neoplasm that arises from primitive transformed cells of mesenchymal origin (and thus a sarcoma) and that exhibits osteoblastic differentiation and produces malignant osteoid.

Osteosarcoma is the most common histological form of primary bone cancer. It is most prevalent in teenagers and young adults.

Ewing's sarcoma is more common in males (1.6 male:1 female) and usually presents in childhood or early adulthood, with a peak between 10 and 20 years of age. It can occur anywhere in the body, but most commonly in the pelvis and proximal long tubular bones, especially around the growth plates. The diaphyses of the femur are the most common sites, followed by the tibia and the humerus. Thirty percent are overtly metastatic at presentation. Patients usually experience extreme bone pain.

Signs and symptoms include: intermittent fevers, anemia, leukocytosis, increased sedimentation rate, and other symptoms of inflammatory systemic illness. Also, depending on the type, progression, and location of the tumor, great pain may occur.

According to the Bone Cancer Research Trust (BCRT), the most common symptoms are: localized pain, swelling, and sporadic bone pain with variable intensity. The swelling is most likely to be visible if the sarcoma is located on a bone near the surface of the body, but when it occurs in other places deeper in the body, like on the pelvis, it may not be visible.

Ewing sarcoma or Ewing's sarcoma () is a malignant small, round, blue cell tumor. It is a rare disease in which cancer cells are found in the bone or in soft tissue. The most common areas in which it occurs are the pelvis, the femur, the humerus, the ribs and clavicle (collar bone).

Since a common genetic locus is responsible for a large percentage of Ewing sarcoma and primitive neuroectodermal tumors, these are sometimes grouped together in a category known as the Ewing family of tumors.

Ewing sarcoma occurs most frequently in teenagers and young adults, with a male/female ratio of 1.6:1.

Although usually classified as a bone tumor, Ewing's sarcoma can have characteristics of both mesodermal and ectodermal origin, making it difficult to classify.

James Ewing (1866–1943) first described the tumour, establishing that the disease was separate from lymphoma and other types of cancer known at that time.

Dogs with limb osteosarcoma typically show lameness and swelling at the affected site. For other sites, dogs may show difficulty to open their mouth (if jaw bone cancer), nasal discharge (if nasal cavity bone cancer) or neurological signs (if spine bone cancer).

The most common bone tumor is called osteosarcoma, and typically affects middle-age to older dogs of large and giant breeds. Osteosarcoma is less common in cats. Osteosarcoma is an aggressive cancer that can develop in any bone of the body but the majority is seen in the limbs (e.g. long bones such as radius, humerus, femur, and tibia).

A sarcoma is a cancer that arises from transformed cells of mesenchymal origin. Thus, malignant tumors made of cancellous bone, cartilage, fat, muscle, vascular, or hematopoietic tissues are, by definition, considered sarcomas. This is in contrast to a malignant tumor originating from epithelial cells, which are termed carcinoma. Human sarcomas are quite rare. Common malignancies, such as breast, colon, and lung cancer, are almost always carcinoma. The term is from the Greek "sarx" meaning "flesh".

Patients usually present with pain and limited range of motion caused by tumor's proximity to the joint space. Swelling may occur, as well, if the tumor has been growing for a long time. Some patients may be asymptomatic until they develop a pathologic fracture at the site of the tumor. They usually originate from the epiphysis of long bones, but in rare cases, they may arise from anterior arc of the ribs.

The symptoms may include muscular aches and pains in arms or legs and abdominal pain. Patients may also experience nerve pain which feels like an electric shock due to weight bearing.

Bone tumors may be classified as "primary tumors", which originate in bone or from bone-derived cells and tissues, and "secondary tumors" which originate in other sites and spread (metastasize) to the skeleton. Carcinomas of the prostate, breasts, lungs, thyroid, and kidneys are the carcinomas that most commonly metastasize to bone. Secondary malignant bone tumors are estimated to be 50 to 100 times as common as primary bone cancers.

The most common cancers in children are (childhood) leukemia (32%), brain tumors (18%), and lymphomas (11%). In 2005, 4.1 of every 100,000 young people under 20 years of age in the U.S. were diagnosed with leukemia, and 0.8 per 100,000 died from it. The number of new cases was highest among the 1–4 age group, but the number of deaths was highest among the 10–14 age group.

In 2005, 2.9 of every 100,000 people 0–19 years of age were found to have cancer of the brain or central nervous system, and 0.7 per 100,000 died from it. These cancers were found most often in children between 1 and 4 years of age, but the most deaths occurred among those aged 5–9. The main subtypes of brain and central nervous system tumors in children are: astrocytoma, brain stem glioma, craniopharyngioma, desmoplastic infantile ganglioglioma, ependymoma, high-grade glioma, medulloblastoma and atypical teratoid rhabdoid tumor.

Other, less common childhood cancer types are:

- Neuroblastoma (6%, nervous system)

- Wilms tumor (5%, kidney)

- Non-Hodgkin lymphoma (4%, blood)

- Childhood rhabdomyosarcoma (3%, many sites)

- Retinoblastoma (3%, eye)

- Osteosarcoma (3%, bone cancer)

- Ewing sarcoma (1%, many sites)

- Germ cell tumors (5%, many sites)

- Pleuropulmonary blastoma (lung or pleural cavity)

- Hepatoblastoma and hepatocellular carcinoma (liver cancer)

A bone tumor (also spelled bone tumour) is a neoplastic growth of tissue in bone. Abnormal growths found in the bone can be either benign (noncancerous) or malignant (cancerous).

Average five-year survival in the United States after being diagnosed with bone and joint cancer is 67%.

Giant-cell tumor of the bone (GCTOB) is a relatively uncommon tumor of the bone. It is characterized by the presence of multinucleated giant cells (osteoclast-like cells). Malignancy in giant-cell tumor is uncommon and occurs in about 2% of all cases. However, if malignant degeneration does occur, it is likely to metastasize to the lungs. Giant-cell tumors are normally benign, with unpredictable behavior. It is a heterogeneous tumor composed of three different cell populations. The giant-cell tumour stromal cells (GCTSC) constitute the neoplastic cells, which are from an osteoblastic origin and are classified based on expression of osteoblast cell markers such as alkaline phosphatase and osteocalcin. In contrast, the mononuclear histiocytic cells (MNHC) and multinucleated giant cell (MNGC) fractions are secondarily recruited and comprise the non-neoplastic cell population. They are derived from an osteoclast-monocyte lineage determined primarily by expression of "CD68", a marker for monocytic precursor cells. In most patients, the tumors are slow to develop, but may recur locally in as many as 50% of cases.

Sarcomas are given a number of different names based on the type of tissue that they most closely resemble. For example, osteosarcoma resembles bone, chondrosarcoma resembles cartilage, liposarcoma resembles fat, and leiomyosarcoma resembles smooth muscle.

Because different parts of the brain are responsible for different functions, symptoms vary depending on the site of metastasis within the brain. However, brain metastases should be considered in any cancer patient who presents with neurological or behavioral changes.

Brain metastases can cause a wide variety of symptoms which can also be present in minor, more common conditions. Neurological symptoms are often caused by increased intracranial pressure, with severe cases resulting in coma. The most common neurological symptoms include:

- New onset headaches: headaches occur in roughly half of brain metastasis patients, especially in those with many tumors.

- Paresthesias: patients often present with (hemiparesis), or weakness on only one side of the body, which is often a result of damage to neighboring brain tissue.

- Ataxia: when metastasis occurs to the cerebellum, patients will experience various difficulties with spatial awareness and coordination.

- Seizures: when present, often indicates disease involvement of the cerebral cortex.

Patients with osteoblastoma usually present with pain of several months' duration. In contrast to the pain associated with osteoid osteoma, the pain of osteoblastoma usually is less intense, usually not worse at night, and not relieved readily with salicylates (aspirin and related compounds). If the lesion is superficial, the patient may have localized swelling and tenderness. Spinal lesions can cause painful scoliosis, although this is less common with osteoblastoma than with osteoid osteoma. In addition, lesions may mechanically interfere with the spinal cord or nerve roots, producing neurologic deficits. Pain and general weakness are common complaints.

The most common sources of brain metastases in a case series of 2,700 patients undergoing treatment at the Memorial Sloan–Kettering Cancer Center were:

- Lung cancer, 48%

- Breast cancer, 15%

- Genitourinary tract cancers, 11%

- Osteosarcoma, 10%

- Melanoma, 9%

- Head and neck cancer, 6%

- Neuroblastoma, 5%

- Gastrointestinal cancers, especially colorectal and pancreatic carcinoma, 3%

- Lymphoma, 1%

Lung cancer and melanoma are most likely to present with multiple metastasis, whereas breast, colon, and renal cancers are more likely to present with a single metastasis.

Osteoblastoma is an uncommon osteoid tissue-forming primary neoplasm of the bone.

It has clinical and histologic manifestations similar to those of osteoid osteoma; therefore, some consider the two tumors to be variants of the same disease, with osteoblastoma representing a giant osteoid osteoma. However, an aggressive type of osteoblastoma has been recognized, making the relationship less clear.

Although similar to osteoid osteoma, it is larger (between 2 and 6 cm).

Bone metastases are a major clinical concern that can cause severe pain, bone fractures, spinal cord compression, hypercalcemia, anemia, spinal instability, decreased mobility, and rapid degradation in the quality of life for patients. Patients have described the pain as a dull ache that grows worse over time, with intermittent periods of sharp, jagged pain. Even under controlled pain management, these periods of breakthrough pain can occur rapidly, without warning, several times a day. Pain may be worse at night and partially relieved by activity. Metastases to weightbearing bones may become symptomatic early in the course of disease as compared to metastases to the flat bones of the rib or sternum.

- Effects of bone metastasis

- severe pain

- bone fractures

- spinal cord compression

- hypercalcemia

- anemia

- spinal instability

- decreased mobility

Bone metastases, or metastatic bone disease, is a class of cancer metastases that results from primary tumor invasion to bone. Bone-originating primary tumors such as osteosarcoma, chondrosarcoma, and Ewing's sarcoma are rare. Unlike hematological malignancies that originate in the blood and form non-solid tumors, bone metastases generally arise from epithelial tumors and form a solid mass inside the bone. Bone metastases cause severe pain, characterized by a dull, constant ache with periodic spikes of incident pain.

Mucinous cystadenocarcinoma of the lung (MCACL) is a very rare malignant mucus-producing neoplasm arising from the uncontrolled growth of transformed epithelial cells originating in lung tissue.

Childhood cancer (also known as pediatric cancer) is cancer in a child. In the United States, an arbitrarily adopted standard of the ages used are 0–14 years inclusive, that is, up to 14 years 11.9 months of age. However, the definition of childhood cancer sometimes includes adolescents between 15–19 years old. Pediatric oncology is the branch of medicine concerned with the diagnosis and treatment of cancer in children.

Worldwide, it is estimated that childhood cancer has an incidence of more than 175,000 per year, and a mortality rate of approximately 96,000 per year. In developed countries, childhood cancer has a mortality of approximately 20% of cases. In low resource settings, on the other hand, mortality is approximately 80%, or even 90% in the world's poorest countries. In many developed countries the incidence is slowly increasing, as rates of childhood cancer increased by 0.6% per year between 1975 and 2002 in the United States and by 1.1% per year between 1978 and 1997 in Europe.

The classical LFS malignancies - sarcoma, cancers of the breast, brain and adrenal glands - comprise about 80% of all cancers that occur in this syndrome.

The risk of developing any invasive cancer (excluding skin cancer) is ~50% by age 30 (1% in the general population) and is 90% by age 70. Early onset breast cancer accounts for 25% of all the cancers in this syndrome. This is followed by soft tissue sarcomas (20%), bone sarcoma (15%) and brain tumors - especially glioblastomas - (13%). Other tumours seen in this syndrome include leukemia, lymphoma and adrenocortical carcinoma.

~90% of females with LFS develop breast cancer by age 60 years; the majority of these occur before age 45 years. Females with this syndrome have almost a 100% lifetime risk of developing cancer. This compares with 73% for affected males. The difference may be due to much smaller breast tissue in males as well as increased estrogen levels in females.

The risks of sarcoma, female breast cancer and haematopoietic malignancies in mutation carriers are more than 100 times greater than those seen in the general population.

Other tumours reported in this syndrome but not yet proved to be linked with it include melanoma, Wilm's and other kidney tumors, hepatacellular carcinoma, gonadal germ cell, pancreatic, gastric, choroid plexus, colorectal and prostate cancers.

80% of children with adrenocortical carcinoma and 2%-10% of childhood brain tumors have p53 mutations.

2%-3% of osteosarcomas, 9% rhabdomyosarcomas and 7%-20% patients with multiple primary tumors have p53 mutations.

Although most cases of this syndrome have early onset of cancer, cases have also been reported later in life.

Adult patients have worsening myalgias, bone pains and fatigue which are followed by recurrent fractures. Children present with difficulty in walking, stunted growth and deformities of the skeleton (features of rickets).

Several other terms for this lesion have been used in the past medical literature, including mucinous multilocular cyst carcinoma, pseudomyxomatous pulmonary adenocarcinoma, mucinous cystic tumor of low malignant potential, and others.

Li–Fraumeni syndrome is diagnosed if the following three criteria are met:

- the patient has been diagnosed with a sarcoma at a young age (below 45),

- a first-degree relative has been diagnosed with any cancer at a young age (below 45), and

- another first-degree or a second-degree relative has been diagnosed with any cancer at a young age (below 45) or with a sarcoma at any age.

Other criteria have also been proposed:

- a proband with any childhood cancer or sarcoma, brain tumor or adrenal cortical carcinoma diagnosed before age 45

- a first or second degree relative with a typical LFS malignancy (sarcoma, leukaemia, or cancers of the breast, brain or adrenal cortex) regardless of age at diagnosis

and/or

- a first or second degree relative with any cancer diagnosed before age 60.

A third criterion has been proposed

- two first or second degree relatives with LFS-related malignancies at any age.