Chondromyxoid fibroma of the skull base: differential diagnosis and radiotherapy: two case reports and a review of the literature.

Chondromyxoid fibromas are uncommon tumours mostly arising in long bones of young males. Involvement of the skull base is extremely rare. We describe two new cases of base of the skull chondromyxoid fibromas. The tumours were incompletely excised and irradiated with protons because of the high risk of complications of another surgical procedure. The rationale for proton therapy was based on the intimate relations between the tumour and the organs at risk. Skull base chondromyxoid fibroma is a very rare, slowly growing benign tumour that can cause severe disabilities due to tumour compression of critical structures. Only surgical resection has been shown to be relatively effective. We report two cases of incompletely excised lesions treated by postoperative high-dose radiation including proton therapy with no active disease and complication. Our review of the literature allows us to conclude that histological diagnosis of lesions in this site is a trap for pathologists and that radiotherapy is not contraindicated.

Lesión ósea en maxilar superior en niño de 7 años: tumor de células gigantes / Bone lesion in maxilla in a seven-year-old boy: giant cell tumor

Se presenta el caso clínico de un varón de siete años con una lesión ósea solitaria en maxilar superior, descubierta de forma incidental en radiografía simple. Se trata de una lesión lítica, expansiva, con adelgazamiento cortical y abombamiento del hueso, sin mineralización interna, compatible radiológicamente con tumor de células gigantes, a pesar de la edad del paciente y la localización de la lesión. El diagnóstico se confirma con estudio anatomopatológico y se practica resección del tumor. Los tumores de células gigantes son tumores óseos primarios benignos relativamente frecuentes. En nuestro caso, el interés se centra en la importancia de la alta sospecha radiológica, ya que la frecuencia de aparición de estos tumores en individuos menores de 14 años es menor del 3%, y menos del 1% se localizan en el hueso maxilar. A propósito de este caso, se efectúa una revisión de las características radiológicas de estas lesiones, así como de su histología, historia natural y tratamiento, y pronóstico, ya que el conocimiento en profundidad de esta entidad es fundamental para establecer una correcta sospecha diagnóstica desde el inicio del estudio, especialmente en niños, en los que estos tumores son infrecuentes

We report the case of a seven-year-old boy with a solitary bone lesion in maxilla that was discovered incidentally on plain radiography. It was a lytic, expansive lesion with cortical thinning and bone swelling, but no internal mineralization. Despite the age of the patient and the site of the lesion, radiological examination revealed a lesion that was compatible with giant cell tumor. The histological study confirmed this diagnosis and the mass was resected. Giant cell tumors are relatively common primary, benign bone lesions. The case we present is of particular interest because of the important role of radiology in leading us to suspect this tumor, which has an incidence of less than 3% in children under 14 years of age, while less than 1% of them occur in maxilla. We propose a review of the radiological features of these tumors, as well as the histological findings, natural history, treatment and prognosis, since the in-depth knowledge of these lesions is essential for establishing the correct diagnostic suspicion at the start of the study. This is especially true in children, in whom these tumors are rare

"Primary" aggressive chondroblastoma of the humerus: a case report.

BACKGROUND: Chondroblastomas are rare epiphyseal bone tumors. Very few cases with extra-cortical aggressive soft tissue invasion or metastasis are reported. CASE PRESENTATION: We report a 28 year-old adult male who presented with a large swelling over the left shoulder region. Pre-operative imaging revealed a large tumor arising from upper end of humerus with extensive soft tissue involvement necessitating a fore-quarter amputation. Patient received adjuvant radiation. CONCLUSIONS: This patient is one of the largest chondroblastomas to be reported. Although chondroblastomas are typically benign, rarely they can be locally aggressive or metastatic. Early diagnosis and institution of proper primary therapy would prevent mutilating surgeries and recurrences.

Chondroblastoma of the temporal base with high mitotic activity.

A 24-year-old man presented with a rare chondroblastoma of the temporal base manifesting as local pain accompanied by difficulty in opening the mouth. Gross total removal was achieved at initial surgery, but the tumor demonstrated rapid and destructive regrowth from a very small residual volume without definite histological malignant transformation. Growth activity estimated by MIB-1 staining increased spontaneously from 2.5% at the initial operation to 18.7% at recurrence. Further extensive radical tumor removal by surgeons from multiple disciplines was performed. The patient has been free of recurrence for 3 years without radiotherapy. Chondroblastoma of the temporal bone is widely accepted as a benign tumor and regrowth after gross total removal is very rare. However, some cases of chondroblastoma have potentially high mitotic activity.

Proton radiotherapy in management of pediatric base of skull tumors.

PURPOSE: Primary skull base tumors of the developing child are rare and present a formidable challenge to both surgeons and radiation oncologists. Gross total resection with negative margins is rarely achieved, and the risks of functional, structural, and cosmetic deficits limit the radiation dose using conventional radiation techniques. Twenty-nine children and adolescents treated with conformal proton radiotherapy (proton RT) were analyzed to assess treatment efficacy and safety. MATERIALS AND METHODS: Between July 1992 and April 1999, 29 patients with mesenchymal tumors underwent fractionated proton (13 patients) or fractionated combined proton and photon (16 patients) irradiation. The age at treatment ranged from 1 to 19 years (median 12); 14 patients were male and 15 female. Tumors were grouped as malignant or benign. Twenty patients had malignant histologic findings, including chordoma (n = 10), chondrosarcoma (n = 3), rhabdomyosarcoma (n = 4), and other sarcomas (n = 3). Target doses ranged between 50.4 and 78.6 Gy/cobalt Gray equivalent (CGE), delivered at doses of 1.8-2.0 Gy/CGE per fraction. The benign histologic findings included giant cell tumors (n = 6), angiofibromas (n = 2), and chondroblastoma (n = 1). RT doses for this group ranged from 45.0 to 71.8 Gy/CGE. Despite maximal surgical resection, 28 (97%) of 29 patients had gross disease at the time of proton RT. Follow-up after proton RT ranged from 13 to 92 months (mean 40). RESULTS: Of the 20 patients with malignant tumors, 5 (25%) had local failure; 1 patient had failure in the surgical access route and 3 patients developed distant metastases. Seven patients had died of progressive disease at the time of analysis. Local tumor control was maintained in 6 (60%) of 10 patients with chordoma, 3 (100%) of 3 with chondrosarcoma, 4 (100%) of 4 with rhabdomyosarcoma, and 2 (66%) of 3 with other sarcomas. The actuarial 5-year local control and overall survival rate was 72% and 56%, respectively, and the overall survival of the males was significantly superior to that of the female patients (p = 0.002). Of the patients with benign tumors, 1 patient (giant cell tumor) had local failure at 10 months. The other 8 patients continued to have local tumor control; all 9 patients were alive at last follow-up (actuarial 5-year local control and overall survival rate of 89% and 100%, respectively). Severe late effects (motor weakness and sensory deficits) were observed in 2 (7%) of 29 patients. CONCLUSION: Proton RT for children with aggressively recurring tumors after major skull base surgery can offer a considerable prospect of tumor control and survival. Longer follow-up is necessary to assess the real value of protons, in particular with regard to bone growth and cosmetic outcome.

Locally challenging osteo- and chondrogenic tumors of the axial skeleton: results of combined proton and photon radiation therapy using three-dimensional treatment planning.

PURPOSE: Tumors of the axial skeleton are at high risk for local failure. Total surgical resection is rarely possible. Critical normal tissues limit the efficacy of conventional photon therapy. This study reviews our experience of using combined high dose proton and photon radiation therapy following three-dimensional (3D) treatment planning. METHODS AND MATERIALS: Between December 1980 and September 1992, 47 patients were treated at the Massachusetts General Hospital and Harvard Cyclotron Laboratory for primary or recurrent chordomas and chondrosarcomas (group 1, 20 patients), osteogenic sarcomas (group 2, 15 patients) and giant cell tumors, osteo-or chondroblastomas (group 3, 12 patients). Radiation treatment was given postoperatively in 23 patients, pre- and postoperatively in 17 patients, and 7 patients received radiation therapy as definitive treatment modality following biopsy only. The proton radiation component was delivered using a 160 MeV proton beam and the photon component using megavoltage photons up to 23 MV energy with 1.8-2.0 Cobalt Gray Equivalent (CGE) per fraction, once a day. Total external beam target dose ranged from 55.3 CGE to 82.0 CGE with mean target doses of 73.9 CGE (group 1), 69.8 CGE (group 2), and 61.8 CGE (group 3). RESULTS: Group 1 (chordoma and chondrosarcoma): Five of 14 patients (36%) with chordoma recurred locally, and 2 out of 5 patients developed distant metastasis, resulting in 1 death from disease. A trend for improved local control was noted for primary vs. recurrent tumors, target doses > 77 CGE and gross total resection. All patients with chondrosarcoma achieved and maintained local control and disease-free status. Five-year actuarial local control and overall survival rates were 53% and 50% for chordomas and 100% and 100% for chondrosarcomas, respectively. Group 2 (osteogenic sarcoma): Three of 15 patients (20%) never achieved local control and died within 6 months of completion of radiation treatment. Only 1 out of 12 patients who were controlled for more than 6 months failed locally, yielding a 5-year local control rate of 59% for 15 patients. Overall, 4 patients (27%) developed distant metastasis (two in patients with uncontrolled primary); 4 patients succumbed to their disease, 3 patients died of intercurrent disease, resulting in overall survival of 44% at 5 years. Group 3 (giant cell tumors, osteo- and chondroblastoma): One of 8 patients with giant cell tumor failed locally, 1 patient distantly, and all patients are alive. Three of 4 patients with osteo- or chondroblastoma are alive and well. One patient suffered local recurrence and died of disease. Local control rate and overall survival for this group of 12 patients was 76% and 87% and local control for patients with giant cell tumors 83% at 5 years. In the majority of cases radiotherapy was well tolerated. However, one patient with a large base of skull tumor developed retinopathy, one patient required enucleation of a previously blind eye, and another patient with sacral tumor developed chronic diarrhea. CONCLUSION: Combined proton and photon radiation therapy optimized by 3D treatment planning, allows the delivery of higher radiation doses to tumors of the axial skeleton, while respecting normal tissue constraints. High radiation doses can result in improved long-term local control.

Temporal bone chondroblastoma: big and small.

Chondroblastoma represents approximately one per cent of all primary bone tumours. It is even rarer in the temporal bone and so far only 34 cases have been reported. We report here two cases with chondroblastoma of the temporal bone. The first case was discovered as a small lesion of the attic and root of zygoma. It was removed via mastoidectomy and reconstruction of the bony defect achieved normal external ear canal anatomy and hearing post-operatively. The second case presented as an advanced tumour involving the infratemporal fossa and parapharyngeal space. It was treated surgically via the infratemporal fossa approach. As clear surgical margins were not obtained, post-operative radiotherapy was also given to minimize the chance of recurrence.

Chondroblastoma of the sacrum. A case report.

Death due to a chondroblastoma of the sacrum is uncommon. We report the case of a 48-year-old man with this condition. During a 10-year period, the tumor spread into the retroperitoneal space and was an enormous mass after repeated radiotherapy. The patient died of renal failure. The tumor was histologically benign even at autopsy.

[A case of vertebral chondroblastoma]. / A propos d'une observation de chondroblastome vertébral.

The authors have observed a case of cervical chondroblastoma in a child aged nine years. Clinically there was a mediastinal syndrome, with pulmonary tract infection. Resection was achieved in two stages. One year later a local recurrence was treated by a third resection, followed by radiotherapy. Three years later there was no sign of recurrence. A review of the literature summarises the difficulties of diagnosis.

Metastatic chondroblastoma: report of an unusual case treated with radiotherapy.

Although most chondroblastomas are cured by limited surgical procedures, occasional lesions behave more aggressively and may even metastasize. We report here an unusual case of chondroblastoma, characterized by slow growth, two clinical recurrences following attempts at excision, and pulmonary metastases after a total course of 34 years. This tumor was moderately radiosensitive, as it decreased 50% in size 6 months after a dose of 4000 rads in 4 weeks. Review of the literature suggests that aggressive chondroblastomas may show several types of behavior. Most lesions are unusually aggressive from their inception, displaying local invasion and early recurrence. Other lesions, such as the present case, continue to grow slowly and may eventually metastasize if inadequately resected. This latter type of behavior may exemplify the natural history of untreated chondroblastoma.