Suzan H.M. Verdegaal

Background: A common treatment of low-grade cartilaginous lesions of bone is intralesional curettage with local adjuvant therapy. Because of the wide variety of different diagnoses and treatments, there is still a lack of knowledge about the effectiveness of the use of phenol as local adjuvant therapy in patients with grade-I central chondrosarcoma of a long bone. Methods: A retrospective study was done to assess the clinical and oncological outcomes after intralesional curettage, application of phenol and ethanol, and bone-grafting in eighty-five patients treated between 1994 and 2005. Inclusion criteria were histologically proven grade-I central chondrosarcoma and location of the lesion in a long bone. The average age at surgery was 47.5 years (range, 15.6 to 72.3 years). The average duration of follow-up was 6.8 years (range, 0.2 to 14.1 years). Patients were evaluated periodically with conventional radiographs and gadolinium-enhanced magnetic resonance imaging (Gd-MRI) scans. When a lesion was suspected on the basis of the MRI, the patient underwent repeat intervention. Depending on the size of the recurrent lesion, biopsy followed by radiofrequency ablation (for lesions of <10 mm) or repeat curettage (for those of ≥10 mm) was performed. Results: Of the eighty-five patients, eleven underwent repeat surgery because a lesion was suspected on the basis of the Gd-MRI studies during follow-up. Of these eleven, five had a histologically proven local recurrence (a recurrence rate of 5.9% [95% confidence interval, 0.9% to 10.9%]), and all were grade-I chondrosarcomas. General complications consisted of one superficial infection, and two femoral fractures within six weeks after surgery. Conclusions: This retrospective case series without controls has limitations, but the use of phenol as an adjuvant after intralesional curettage of low-grade chondrosarcoma of a long bone was safe and effective, with a recurrence rate of <6% at a mean of 6.8 years after treatment. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Phenol is widely used for years as local adjuvant treatment for bone tumours. Despite its use for a long time, no information is available about the local concentration of phenol that is achieved in an individual patient, and the most sufficient and safe procedure to wash out the phenol after using it as local adjuvant.

Learning Objectives: After completing this course, the reader will be able to: Describe major enchondroma distribution patterns that were identified in this study.Identify variables that are predictive for the secondary transformation of enchondroma over the lifetime of individuals with Ollier disease or Maffucci syndrome. CME This article is available for continuing medical education credit at CME.TheOncologist.com Background.: Enchondromatosis is characterized by the presence of multiple benign cartilage lesions in bone. While Ollier disease is typified by multiple enchondromas, in Maffucci syndrome these are associated with hemangiomas. Studies evaluating the predictive value of clinical symptoms for development of secondary chondrosarcoma and prognosis are lacking. This multi-institute study evaluates the clinical characteristics of patients, to get better insight on behavior and prognosis of these diseases. Method.: A retrospective study was conducted using clinical data of 144 Ollier and 17 Maffucci patients from 13 European centers and one national databank supplied by members of the European Musculoskeletal Oncology Society. Results.: Patients had multiple enchondromas in the hands and feet only (group I, 18%), in long bones including scapula and pelvis only (group II, 39%), and in both small and long/flat bones (group III, 43%), respectively. The overall incidence of chondrosarcoma thus far is 40%. In group I, only 4 patients (15%) developed chondrosarcoma, in contrast to 27 patients (43%) in group II and 26 patients (46%) in group III, respectively. The risk of developing chondrosarcoma is increased when enchondromas are located in the pelvis (odds ratio, 3.8; p = 0.00l). Conclusions.: Overall incidence of development of chondrosarcoma is 40%, but may, due to age-dependency, increase when considered as a lifelong risk. Patients with enchondromas located in long bones or axial skeleton, especially the pelvis, have a seriously increased risk of developing chondrosarcoma, and are identified as the population that needs regular screening on early detection of malignant transformation.

Background: Ollier disease is a rare, non-hereditary disorder which is characterized by the presence of multiple enchondromas (ECs), benign cartilaginous neoplasms arising within the medulla of the bone, with an asymmetric distribution. The risk of malignant transformation towards central chondrosarcoma (CS) is increased up to 35%. The aetiology of Ollier disease is unknown. Methods: We undertook genome-wide copy number and loss of heterozygosity (LOH) analysis using Affymetrix SNP 6.0 array on 37 tumours of 28 Ollier patients in combination with expression array using Illumina BeadArray v3.0 for 7 ECs of 6 patients. Results: Non-recurrent EC specific copy number alterations were found at FAM86D, PRKG1 and ANKS1B. LOH with copy number loss of chromosome 6 was found in two ECs from two unrelated Ollier patients. One of these patients also had LOH at chromosome 3. However, no common genomic alterations were found for all ECs. Using an integration approach of SNP and expression array we identified loss as well as down regulation of POU5F1 and gain as well as up regulation of NIPBL. None of these candidate regions were affected in more than two Ollier patients suggesting these changes to be random secondary events in EC development. An increased number of genetic alterations and LOH were found in Ollier CS which mainly involves chromosomes 9p, 6q, 5q and 3p. Conclusions: We present the first genome-wide analysis of the largest international series of Ollier ECs and CS reported so far and demonstrate that copy number alterations and LOH are rare and non-recurrent in Ollier ECs while secondary CS are genetically unstable. One could predict that instead small deletions, point mutations or epigenetic mechanisms play a role in the origin of ECs of Ollier disease.

Surgery is considered to be the most effective treatment for cartilaginous tumours. In recent years, a trend has emerged for patients with low-grade tumours to be treated less invasively using curettage followed by various forms of adjuvant therapy. We investigated the potential for phenol to be used as an adjuvant. Using a human chondrosarcoma-derived cartilage-producing cell line OUMS-27 as an in vitro model we studied the cytotoxic effect of phenol and ethanol. Since ethanol is the standard substance used to rinse phenol out of a bone cavity, we included an assessment of ethanol to see whether this was an important secondary factor with respect to cell death. The latter was assessed by flow cytometry. A cytotoxic effect was found for concentrations of phenol of 1.5% and of ethanol of 42.5%. These results may provide a clinical rationale for the use of both phenol and ethanol as adjuvant therapy after intralesional curettage in low-grade central chondrosarcoma and justify further investigation.