On conventional radiographs, the most common osseous presentation is a permeative lytic lesion with periosteal reaction. The classic description of lamellated or "onion-skin" type periosteal reaction is often associated with this lesion. Plain films add valuable information in the initial evaluation or screening. The wide zone of transition (e.g. permeative) is the most useful plain film characteristic in differentiation of benign versus aggressive or malignant lytic lesions.

Magnetic resonance imaging (MRI) should be routinely used in the work-up of malignant tumors. It will show the full bony and soft tissue extent and relate the tumor to other nearby anatomic structures (e.g. vessels). Gadolinium contrast is not necessary as it does not give additional information over noncontrast studies, though some current researchers argue that dynamic, contrast-enhanced MRI may help determine the amount of necrosis within the tumor, thus help in determining response to treatment prior to surgery.

Computed axial tomography(CT) can also be used to define the extraosseous extent of the tumor, especially in the skull, spine, ribs, and pelvis. Both CT and MRI can be used to follow response to radiation and/or chemotherapy. Bone scintigraphy can also be used to follow tumor response to therapy.

In the group of malignant small round cell tumors which include Ewing's sarcoma, bone lymphoma, and small cell osteosarcoma, the cortex may appear almost normal radiographically, while permeative growth occurs throughout the Haversian channels. These tumours may be accompanied by a large soft-tissue mass while almost no bone destruction is visible. The radiographs frequently do not shown any signs of cortical destruction.

Radiographically, Ewing's sarcoma presents as "moth-eaten" destructive radiolucencies of the medulla and erosion of the cortex with expansion.

Other entities with similar clinical presentations include osteomyelitis, osteosarcoma (especially telangiectatic osteosarcoma), and eosinophilic granuloma. Soft-tissue neoplasms such as pleomorphic undifferentiated sarcoma (malignant fibrous histiocytoma) that erode into adjacent bone may also have a similar appearance.

Family physicians and orthopedists rarely see a malignant bone tumor (most bone tumors are benign). The route to osteosarcoma diagnosis usually begins with an X-ray, continues with a combination of scans (CT scan, PET scan, bone scan, MRI) and ends with a surgical biopsy. A characteristic often seen in an X-ray is Codman's triangle, which is basically a subperiosteal lesion formed when the periosteum is raised due to the tumor. Films are suggestive, but bone biopsy is the only definitive method to determine whether a tumor is malignant or benign.

Most times, the early signs of osteosarcoma are caught on X-rays taken during routine dental check-ups. Osteosarcoma frequently develops in the mandible (lower jaw); accordingly, Dentist are trained to look for signs that may suggest osteosarcoma. Even though radiographic findings for this cancer vary greatly, one usually sees a symmetrical widening of the periodontal ligament space. If the dentist has reason to suspects osteosarcoma or another underlying disorder, he or she would refer the patient to an Oral & Maxillofacial surgeon for biopsy. A biopsy of suspected osteosarcoma outside of the facial region should be performed by a qualified orthopedic oncologist. The American Cancer Society states: "Probably in no other cancer is it as important to perform this procedure properly. An improperly performed biopsy may make it difficult to save the affected limb from amputation." It may also metastasise to the lungs, mainly appearing on the chest X-ray as solitary or multiple round nodules most common at the lower regions.

On X-ray, giant-cell tumors (GCTs) are lytic/lucent lesions that have an epiphyseal location and grow to the articular surface of the involved bone. Radiologically the tumors may show characteristic 'soap bubble' appearance. They are distinguishable from other bony tumors in that GCTs usually have a nonsclerotic and sharply defined border. About 5% of giant-cell tumors metastasize, usually to a lung, which may be benign metastasis, when the diagnosis of giant-cell tumor is suspected, a chest X-ray or computed tomography may be needed. MRI can be used to assess intramedullary and soft tissue extension.

When diagnosing osteoblastoma, the preliminary radiologic workup should consist of radiography of the site of the patient's pain. However, computed tomography (CT) is often necessary to support clinical and plain radiographic findings suggestive of osteoblastoma and to better define the margins of the lesion for potential surgery. CT scans are best used for the further characterization of the lesion with regard to the presence of a nidus and matrix mineralization. MRI aids in detection of nonspecific reactive marrow and soft tissue edema, and MRI best defines soft tissue extension, although this finding is not typical of osteoblastoma. Bone scintigraphy (bone scan) demonstrates abnormal radiotracer accumulation at the affected site, substantiating clinical suspicion, but this finding is not specific for osteoblastoma. In many patients, biopsy is necessary for confirmation.

The diagnosis of giant-cell tumors is based on biopsy findings. The key histomorphologic feature is, as the name of the entity suggests, (multinucleated) giant cells with up to a hundred nuclei that have prominent nucleoli. Surrounding mononuclear and small multinucleated cells have nuclei similar to those in the giant cells; this distinguishes the lesion from other osteogenic lesions which commonly have (benign) osteoclast-type giant cells. Soap-bubble appearance is a characteristic feature.

Amputation is the initial treatment, although this alone will not prevent metastasis. Chemotherapy combined with amputation improves the survival time, but most dogs still die within a year. Surgical techniques designed to save the leg (limb-sparing procedures) do not improve the prognosis.

Some current studies indicate osteoclast inhibitors such as alendronate and pamidronate may have beneficial effects on the quality of life by reducing osteolysis, thus reducing the degree of pain, as well as the risk of pathological fractures.

The first route of treatment in Osteoblastoma is via medical means. Although necessary, radiation therapy (or chemotherapy) is controversial in the treatment of osteoblastoma. Cases of postirradiation sarcoma have been reported after use of these modalities. However, it is possible that the original histologic diagnosis was incorrect and the initial lesion was an osteosarcoma, since histologic differentiation of these two entities can be very difficult.

The alternative means of treatment consists of surgical therapy. The treatment goal is complete surgical excision of the lesion. The type of excision depends on the location of the tumor.

- For stage 1 and 2 lesions, the recommended treatment is extensive intralesional excision, using a high-speed burr. Extensive intralesional resections ideally consist of removal of gross and microscopic tumor and a margin of normal tissue.

- For stage 3 lesions, wide resection is recommended because of the need to remove all tumor-bearing tissue. Wide excision is defined here as the excision of tumor and a circumferential cuff of normal tissue around the entity. This type of complete excision is usually curative for osteoblastoma.

In most patients, radiographic findings are not diagnostic of osteoblastoma; therefore, further imaging is warranted. CT examination performed with the intravenous administration of contrast agent poses a risk of an allergic reaction to contrast material.

The lengthy duration of an MRI examination and a history of claustrophobia in some patients are limiting the use of MRI. Although osteoblastoma demonstrates increased radiotracer accumulation, its appearance is nonspecific, and differentiating these lesions from those due to other causes involving increased radiotracer accumulation in the bone is difficult. Therefore, bone scans are useful only in conjunction with other radiologic studies and are not best used alone.

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.

Surgery is important in the treatment of most sarcomas. Limb sparing surgery, as opposed to amputation, can now be used to save the limbs of patients in at least 90% of extremity tumor cases. Additional treatments, including chemotherapy and radiation therapy, may be administered before and/or after surgery. Chemotherapy significantly improves the prognosis for many sarcoma patients, especially those with bone sarcomas. Treatment can be a long and arduous process, lasting about a year for many patients.

- Liposarcoma treatment consists of surgical resection, with chemotherapy not being used outside of the investigative setting. Adjuvant radiotherapy may also be used after surgical excision for liposarcoma.

- Rhabdomyosarcoma is treated with surgery, radiotherapy, and/or chemotherapy. The majority of rhabdomyosarcoma patients have a 50–85% survival rate.

- Osteosarcoma is treated with surgical resection of as much of the cancer as possible, often along with neoadjuvant chemotherapy. Radiotherapy is a second alternative although not as successful.

Recurrence rate of solid form of tumour is lower than classic form.

The initial evaluation involves radiographs (X-rays) of the affected site, but the only way to confirm the diagnosis is by sampling the tissue via biopsy or needle aspiration.

Treatment of bone tumors is highly dependent on the type of tumor.

A 2009 revision of the traditional Chompret criteria for screening has been proposed:

A proband who has:

- tumor belonging to the LFS tumor spectrum - soft tissue sarcoma, osteosarcoma, pre-menopausal breast cancer, brain tumor, adrenocortical carcinoma, leukemia or lung bronchoalveolar cancer - before age 46 years;

and at least one of the following:

- at least one first or second degree relative with an LFS tumour (except breast cancer if the proband has breast cancer) before age 56 years or with multiple tumours

- a proband with multiple tumours (except multiple breast tumours), two of which belong to the LFS tumour spectrum and the first of which occurred before age 46 years

- a proband who is diagnosed with adrenocortical carcinoma or choroid plexus tumour, irrespective of family history

Genetic counseling and genetic testing are used to confirm that somebody has this gene mutation. Once such a person is identified, early and regular screenings for cancer are recommended for him or her as people with Li–Fraumeni are likely to develop another primary malignancy at a future time (57% within 30 years of diagnosis).

Depending on the pet's unique condition, there are several treatment options, including surgery, chemotherapy and radiation therapy. Treating the pain adequately is also of crucial importance to improve the pet's quality of life, especially if amputation is not performed.

Following conditions are excluded before diagnosis can be confirmed:

- Unicameral bone cyst

- Giant cell tumor

- Telangiectatic osteosarcoma

- Secondary aneurysmal bone cyst

The 5-year disease-free survival for age >5 years is 50-60%. Another report found a similar 5-year survival at about 65% with 51% progression-free survival. The 10-year disease-free survival is 40-50%. Younger ages showed lower 5 and 10-year survival rates. A 2006 study that observed 133 patients found 31 (23.3%) had a recurrence of the disease within a five-year period.

Brain imaging (neuroimaging such as CT or MRI) is needed to determine the presence of brain metastases. In particular, contrast-enhanced MRI is the best method of diagnosing brain metastases, though detection is primarily done by CT. Biopsy is often recommended to confirm diagnosis.

The diagnosis of brain metastases typically follows a diagnosis of a systemic cancer. Occasionally, brain metastases will be diagnosed concurrently with a primary tumor or before the primary tumor is found.

Chemotherapy and radiotherapy are effective in some tumors (such as Ewing's sarcoma) but less so in others (such as chondrosarcoma).

There is a variety of chemotherapy treatment protocols for bone tumors. The protocol with the best reported survival in children and adults is an intra-arterial protocol where tumor response is tracked by serial arteriogram. When tumor response has reached >90% necrosis surgical intervention is planned.

Use of telomerase inhibitors such as Imetelstat seem to have very low toxicity compared to other chemotherapy. The only known side effect of most telomerase inhibitors is dose-induced neutropenia. Neuropsychological deficits can result from resection, chemotherapy, and radiation, as well as endocrinopathies. Additionally, an increase in gastrointestinal complications has been observed in survivors of pediatric cancers.

The Ewing family of tumors is a group of cancers that includes Ewing tumor of bone (ETB or Ewing sarcoma of bone), extraosseous Ewing tumors (EOE tumors), primitive neuroectodermal tumors (PNET or peripheral neuroepithelioma), and Askin tumors (PNET of the chest wall). These tumors all come from the same type of stem cell. Also called EFTs.

Biochemical studies reveal hypophosphatemia (low blood phosphate), elevated alkaline phosphatase and low serum 1, 25 dihydroxyvitamin D levels. Routine laboratory tests do not include serum phosphate levels and this can result in considerable delay in diagnosis. Even when low phosphate is measured, its significance is often overlooked. The next most appropriate test is measurement of urine phosphate levels. If there is inappropriately high urine phosphate (phosphaturia) in the setting of low serum phosphate (hypophosphatemia), there should be a high suspicion for tumor-induced osteomalacia. FGF23 (see below) can be measured to confirm the diagnosis but this test is not widely available.

Once hypophosphatemia and phosphaturia have been identified, a search for the causative tumor should begin. These are small and difficult to define. Gallium-68 DOTA-Octreotate (DOTA-TATE) positron emission tomography (PET) scanning is the best way to locate these tumors. If this scan is not available, other options include Indium-111 Octreotide (Octreoscan) SPECT/CT, whole body CT or MRI imaging.

Serum chemistries are identical in tumor-induced osteomalacia, X-linked hypophosphatemic rickets (XHR) and autosomal dominant hypophosphatemic rickets (ADHR). A negative family history can be useful in distinguishing tumor induced osteomalacia from XHR and ADHR. If necessary, genetic testing for PHEX (phosphate regulating gene with homologies to endopepetidase on the X-chromosome) can be used to conclusively diagnose XHR and testing for the FGF-23 gene will identify patients with ADHR.

The prognosis for brain metastases is variable. It depends on the type of primary cancer, the age of the patient, the absence or presence of extracranial metastases, and the number of metastatic sites in the brain. For patients who do not undergo treatment the average survival is between one and two months. However, in some patients, such as those with no extracranial metastases, those who are younger than 65, and those with a single site of metastasis in the brain only, prognosis is much better, with median survival rates of up to 13.5 months. Because brain metastasis can originate from various different primary cancers, the Karnofsky performance score is used for a more specific prognosis.