Although not specific to one mode of management, lesion size, patient sex, or follow-up, the recurrence rate for chondroblastoma is relatively high, and has been shown in select studies to be dependent upon the anatomical location, method of treatment, and biological aggressiveness of the initial lesion. The rate of recurrence is highly variable, ranging between 5% and 40%, as study results are generally inconclusive. However, local recurrence for long bone lesions is around 10%, with chondroblastoma in flat bones having higher recurrence and more complications. Recurrences are more common in cases involving an open epiphyseal plate where they can be attributed to inadequate curettage to avoid damage. Lesions of the proximal femur are particularly problematic because of difficulties accessing the femoral head for complete excision. Chondroblastoma may recur in the soft tissue surrounding the initial lesion, especially in the case of incomplete curettage. Recurrences have been shown to occur between 5 months and 7 years after initial treatment and are generally treated with repeat curettage and excision of affected soft-tissue. No histological differences have been seen between recurrent and non-recurrent chondroblastomas.

Rarely, more aggressive chondroblastomas can metastasize. The most common location for metastases is the lung, with some cases also involving secondary bone sites, soft tissue, skin, or the liver. The prevalence of metastatic chondroblastoma, however, is quite low and is believed to be less than 1%. There is no relationship established between metastasis and previous surgery, non-surgical treatment, anatomical location, or patient age. Survival of patients with metastatic lesions is better when the metastases are surgically resectable, as chemotherapy has been shown to have little to no benefit. Prognosis is bleak for patients with malignant chondroblastomas that are resistant to surgery, radiation, and chemotherapy. However, patients with resectable metastases have survived for several years following diagnosis.

While recurrence is the most common complication of chondroblastoma other issues include post-surgery infection, degenerative joint disease, pathological fractures, failure of bone grafts, pre-mature epiphyseal closure, functional impairment, and malignant transformation. Complications are less common in patients presenting with chondroblastoma in accessible areas. Overall, patients with more classical chondroblastoma (appearing in long bones, typical presentation) have better prognoses than patients with atypical chondroblastoma (flat bones, skull, etc.).

Currently, the genetic or environmental factors that predispose an individual for chondroblastoma are not well known or understood. Chondroblastoma affects males more often than females at a ratio of 2:1 in most clinical reports. Furthermore, it is most often observed in young patients that are skeletally immature, with most cases diagnosed in the second decade of life. Approximately 92% of patients presenting with chondroblastoma are younger than 30 years. There is no indication of a racial predilection for chondroblastoma.

Giant-cell tumor of the bone accounts for 4-5% of primary bone tumors and about 20% of benign bone tumors. However, significantly higher incidence rates are observed in Asia, where it constitutes about 20% of all primary bone tumors in China. It is slightly more common in females, has a predilection for the epiphyseal/metaphyseal region of long bones, and generally occurs in the third to fourth decade. Although classified as a benign tumor, GCTOB has been observed to metastesize to the lungs in up to 5% of cases, and in rare instances (1-3%) can transform to the malignant sarcoma phenotype with equal disease outcome.

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

A number of tumors have giant cells, but are not true benign giant-cell tumors. These include, aneurysmal bone cyst, chondroblastoma, simple bone cyst, osteoid osteoma, osteoblastoma, osteosarcoma, giant-cell reparative granuloma, and brown tumor of hyperparathyroidism.

It is common in age group of 10–30 years. It is second most common tumor of spine and commonest benign tumor of pelvis in pediatric population. Incidence is slightly more in males than females (1.3:1).

Many types of blastoma have been linked to a mutation in tumor suppressor genes. For example, pleuropulmonary blastomas have been linked to a mutation of the coding for p53. However, the mutation which allows proliferation of incompletely differentiated cells can vary from patient to patient and a mutation can alter the prognosis. In the case of retinoblastoma, patients carry a visibly abnormal karyotype, with a loss of function mutation on a specific band of chromosome 13. This recessive deletion on the rb gene is also associated with other cancer types and must be present on both alleles, for a normal cell to progress towards malignancy.

A blastoma is a type of cancer, more common in children, that is caused by malignancies in precursor cells, often called blasts. Examples are nephroblastoma, medulloblastoma and retinoblastoma. The suffix "-blastoma" is used to imply a tumor of primitive, incompletely differentiated (or precursor) cells, e.g., chondroblastoma is composed of cells resembling the precursor of chondrocytes.