Concurrent intraosseous cartilaginous lesions in patients with multiple osteochondromas identified on total-body MR imaging.

PURPOSE: To assess the prevalence of intraosseous cartilaginous lesions in patients with multiple osteochondromas based on total-body (TB) MRI examinations, used for screening purposes. SUBJECTS AND METHODS: Between 2013 and 2020, TB-MRI examinations were performed in 366 patients with proven multiple osteochondromas syndrome, to rule out malignant progression. For this study, presence, or absence of intraosseous central or eccentrical chondroid lesions, defined as lobulated lesions with low signal intensity on T1-weighted images, replacing bone marrow and high signal intensity equal to fluid on T2-weighted images in the bone marrow of the meta-diaphysis of (one of) the long bones, were recorded in the long bones as part of a TB-MRI protocol. RESULTS: In 62 patients out of the 366 MO patients (17%), one or more intraosseous chondroid lesions (either enchondroma or atypical cartilaginous tumor) were detected. The age of the patients at time of diagnosis ranged from 17 to 61 years (mean, 36). Size of the lesions varied from 4 to 69 mm (mean, 16.3 mm). The most common location was the proximal femur (n = 29), followed by the distal femur and proximal humerus (n = 18 and n = 10, respectively). In nine of the patients with an intraosseous chondroid lesion, a second and/or third TB-MRI were available during the period of evaluation (mean interval, 2.7 years between the exams). In none of these patients increase of these intraosseous lesions was noticed. CONCLUSION: Intraosseous chondroid lesions (enchondroma and ACT) appear to occur more frequently in MO patients than in the general population. TB-MRI allows to detect these, besides the identification of OC with suspicious features.

Osteoscopic versus open surgery for the treatment of enchondroma in the foot.

INTRODUCTION: The conventional treatment of enchondromas is the open surgery with curettage of lesions. Osteoscopic surgery is a minimally invasive endoscopic approach for lesions inside bone. The aim of this study was to evaluate the feasibility of the osteoscopic surgery in comparison with the conventional open surgery for patients with foot enchondromas. MATERIALS AND METHODS: A retrospective cohort study comparing patients with foot enchondromas treated with osteoscopic or open surgery from 2000 to 2019. Functional evaluations were based on both the AOFAS score and the Musculoskeletal Tumor Society (MSTS) functional rate. Complication and local recurrence were evaluated. RESULTS: Seventeen patients underwent endoscopic surgery, and eight patients underwent open surgery. The AOFAS score was higher in the osteoscopic group than the open group at 1 and 2 weeks after surgery (mean, 89.18 vs 67.25 [p = 0.001], 93.88 vs 79.38 [p = 0.004]). The MSTS functional rate was also higher in the osteoscopic group than the open group at 1 and 2 weeks after surgery (mean, 81.96 vs 59.58% [p = 0.00], 90.98 vs 75.00% [p = 0.02]). No statistical differences were found after 1-month of surgery. The osteoscopic group had lower complication rate than the open group (12 vs 50%; p = 0.04). No local recurrence was found in any groups. CONCLUSION: The osteoscopic surgery is feasible to provide earlier functional recovery and fewer complications than the open surgery.

Evaluation of triage tool for low-grade cartilage tumors: Four-quadrant approach.

BACKGROUND AND OBJECTIVES: The "four-quadrant approach" (FQA) for triage of benign enchondromas (E) and low-grade malignant chondrosarcomas (LGC) divides patients into treatment categories based on the presence or absence of pain and observation of aggressive or benign radiographic features. This article evaluates the usefulness of the FQA in predicting E versus LGC and operative versus nonoperative outcome. METHODS: Patients had working diagnosis of E or LGC, 1-year minimum follow-up, imaging, clinical data, outcomes, and no radiographic evidence of high-grade chondrosarcoma. Statistical analysis determined whether quadrant distribution correlated to E versus LGC and operative versus nonoperative intervention. RESULTS: Of 56 lesions (49 patients), 9 were LGC and 47 E. Twenty-five lesions (all 9 LGC, 16 E) were treated operatively and 31 (all E) nonoperatively. There were statistically significant correlations between quadrant distribution and both tumor type (p = 1.9 × 10-6 ) and operative intervention (p = 6.28 × 10-6 ). CONCLUSIONS: The FQA is a promising diagnostic tool to distinguish between E and LGC hyaline cartilage tumors, along with determining operative versus nonoperative intervention. Prospective evaluation is warranted.

Assessment of central cartilaginous tumor of the appendicular bone: inter-observer and intermodality agreement and comparison of diagnostic performance of CT and MRI.

BACKGROUND: Diagnostic performance, inter-observer agreement, and intermodality agreement between computed tomography (CT) and magnetic resonance imaging (MRI) in the depiction of the major distinguishing imaging features of central cartilaginous tumors have not been investigated. PURPOSE: To determine the inter-observer and intermodality agreement of CT and MRI in the evaluation of central cartilaginous tumors of the appendicular bones, and to compare their diagnostic performance. MATERIAL AND METHODS: Two independent radiologists retrospectively reviewed preoperative CT and MRI. Inter-observer and intermodality agreement between CT and MRI in the assessment of distinguishing imaging features, including lesion size, deep endosteal scalloping, cortical expansion, cortical disruption, pathologic fracture, soft tissue extension, and peritumoral edema, were evaluated. The agreement with histopathology and the accuracy of the radiologic diagnoses made with CT and MRI were also analyzed. RESULTS: A total of 72 patients were included. CT and MRI showed high inter-observer and intermodality agreements with regard to size, deep endosteal scalloping, cortical expansion, cortical disruption, and soft tissue extension (ICC = 0.96-0.99, k = 0.60-0.90). However, for the evaluation of pathologic fracture, MRI showed only moderate inter-observer agreement (k = 0.47). Peritumoral edema showed only fair intermodality agreement (k = 0.28-0.33) and moderate inter-observer agreement (k = 0.46) on CT. Both CT and MRI showed excellent diagnostic performance, with high agreement with the histopathology (k = 0.89 and 0.87, respectively) and high accuracy (91.7% for both CT and MRI). CONCLUSION: CT and MRI showed high inter-observer and intermodality agreement in the assessment of several distinguishing imaging features of central cartilaginous tumors of the appendicular bones and demonstrated comparable diagnostic performance.

Rare Presentation of Pediatric Multiple Enchondromatosis Limited to Single Ray or Single Nerve Distribution in the Hand: A Multicenter Case Series.

BACKGROUND: Multiple enchondromas in the pediatric hand is a relatively rare occurrence and the literature regarding its incidence and treatment is sparse. Within this rare subset of patients, we identified a unique cohort in which lesions are confined to multiple bones in a single ray or adjacent rays within a single nerve distribution. We review the clinical and pathologic characteristics and describe the indications for and outcomes of treatment in this unique subset of patients as well as offer conjectures about its occurrence. METHODS: Institutional review board (IRB)-approved retrospective multicenter study between 2010 and 2018 identified subjects with isolated multiple enchondromas and minimum 2-year follow-up. Data analyzed included demographics, lesion quantification and localization, symptoms and/or fracture(s), treatment of lesion(s), complications, recurrence, and presence of malignant transformation. RESULTS: Ten patients were evaluated with average age at presentation of 9 years (range: 4 to 16) and mean clinical follow-up of 6 years (range: 2.8 to 8.6). Five subjects had multiple ray involvement in a single nerve distribution and 5 had single ray involvement with an average of 4 lesions noted per subject (range: 2 to 8). All children in the study had histopathologic-proven enchondromas and underwent operative curettage±bone grafting. Indications for surgical intervention included persistent pain, multiple prior pathologic fractures, impending fracture and deformity. During the study period three subjects experienced pathologic fracture treated successfully with immobilization. Recurrence was noted in 40% at an average of 105 weeks postoperatively (range: 24 to 260) and appears higher than that reported in the literature. No case of malignant transformation was observed during the study period. CONCLUSIONS: A rare subset of pediatric patients with multiple enchondromas of the hand is described with lesions limited to a single ray or single nerve distribution. Further awareness of this unique subset of patients may increase our understanding of the disease and improve patient outcomes. LEVEL OF EVIDENCE: Level IV-therapeutic (case series).

[Soft tissue tumours with FN1 (Fibronectin 1) fusion gene]. / Tumeurs des tissus mous avec fusion du gène FN1 (Fibronectine 1).

Translocations involving FN1 gene have been described in several tumours, which share the presence of a cartilaginous matrix with or without calcifications and a good prognosis. They encompass: soft tissue chondroma, synovial chondromatosis, calcifying aponeurotic fibroma, phosphaturic mesenchymal tumour and a new spectrum of tumours: "the calcified chondroid mesenchymal neoplasms". We review all the clinical, histopathological and molecular data of these tumours and discuss the differential diagnoses.

Curettage and cryosurgery for enchondroma and atypical cartilaginous tumors of the long bones: Oncological results of a large series.

BACKGROUND AND OBJECTIVES: Intralesional surgical treatment is the preferred therapy for atypical cartilaginous tumors (ACTs) of the long bones in many institutions. However, the literature is still controversial regarding intralesional treatment versus wide resection. Due to the relative rarity of these tumors, studies reporting on the results of intralesional treatment are often small sample studies. METHODS: We retrospectively analyzed the oncological results of 55 enchondromas, 119 ACTs, and 5 chondrosarcomas grade 2 (CS2) treated with curettage and cryosurgery between the years 2004 and 2017 at our institution. The median follow-up period was 53 months (range, 24-169 months). RESULTS: In total, seven cases (three ACT, four CS2) recurred. Residual tumor was detected in 20 cases. Three cases underwent secondary curettage and cryosurgery due to local recurrence. Four cases underwent wide resection and reconstruction due to local recurrence with aggressive imaging characteristics. In total, 20 postoperative complications were seen. CONCLUSION: Curettage and cryosurgery for enchondroma and ACT show very good oncological results with a low recurrence rate and acceptable complication rate. Curettage and cryosurgery is reliable as a surgical treatment for enchondroma and ACT. Further research should define the criteria for determining which specific cartilaginous tumors necessitate surgical treatment.

"Slipped capital femoral epiphysis in a 25-year-old hypogonadic man with a large cranial chondroma: causality or coincidence? ".

BACKGROUND: Slipped capital femoral epiphysis (SCFE) is a hip disorder frequently occurring in adolescence. In adults it is rare and so far very few cases have been documented. CASE PRESENTATION: This report presents a 25-year-old patient diagnosed with an anterior fossa giant chondroma, hypogonadotropic hypogonadism, and SCFE. The patient underwent surgical and hormonal therapy. His symptoms revealed, and he became a father. CONCLUSIONS: Every patient diagnosed with SCFE in adulthood should undergo endocrinological assessment based on physical examination and laboratory tests.

Inactivation of Lkb1 in postnatal chondrocytes leads to epiphyseal growth-plate abnormalities and promotes enchondroma-like formation.

Liver serine-threonine kinase B1 (LKB1) is a tumor suppressor that has been linked to many types of tumors. However, the role of LKB1 in cartilaginous tumorigenesis is still poorly understood. In this study, we find that cartilage-specific, tamoxifen-inducible Lkb1 knockout results in multiple enchondroma-like lesions adjacent to the disorganized growth plates. We showed that chondrocytes retain an immature status caused by loss of Lkb1, which may lead to the dramatic expansion of growth-plate cartilage and the formation of enchondroma-like lesions. Additionally, increased mammalian target of rapamycin complex 1 (mTORC1) activity is observed in the Lkb1 conditional knockout (cKO) chondrocytes, and rapamycin (mTORC1 inhibitor) treatment significantly alleviates the expansion of growth-plate cartilage and eliminates the enchondroma-like lesions in Lkb1 cKO mice. Thus, our findings indicate that loss of Lkb1 leads to the expansion of chondrocytes and the formation of enchondroma-like lesions during postnatal cartilage development, and that the up-regulated mTORC1-signaling pathway is implicated in this process. Our findings suggest that modulation of LKB1 and related signaling is a potential therapy in cartilaginous tumorigenesis.-Zhou, S., Li, Y., Qiao, L., Ge, Y., Huang, X., Gao, X., Ju, H., Wang, W., Zhang, J., Yan, J., Teng, H., Jiang, Q. Inactivation of Lkb1 in postnatal chondrocytes leads to epiphyseal growth-plate abnormalities and promotes enchondroma-like formation.

Nonepithelial Tumors of the Larynx: Single-Institution 13-Year Review with Radiologic-Pathologic Correlation.

Nonepithelial tumors of the larynx are rare and represent a minority of all laryngeal neoplasms. Imaging has an important role in the diagnosis, treatment planning, and surveillance of these entities. However, unfamiliarity with these neoplasms can cause diagnostic difficulties for radiologists, especially because many of the imaging findings are nonspecific. By using a systematic approach based on clinical history, patient age and gender, lesion location, endoscopic results, and specific imaging findings, the differential diagnosis can often be narrowed. These tumors typically affect the submucosal layer, so if a tumor has an intact mucosa at endoscopy, a nonepithelial neoplasm is the most likely diagnosis. Nonepithelial tumors of the larynx can arise from the laryngeal cartilage or muscle or from the surrounding lymphoid tissue or blood vessels. Consequently, imaging findings typically correspond to the specific cell type from which it originated. Recognizing specific features (eg, metaplastic bone formation, macroscopic fat, or enhancement pattern) can often help narrow the differential diagnosis. In addition, identification of noncircumscribed borders of the lesion and invasion of the adjacent structures is key to diagnosis of a malignant process rather than a benign neoplasm. Understanding the pathologic correlation is fundamental to understanding the radiologic manifestations and is ultimately crucial for differentiation of nonepithelial laryngeal neoplasms. Online supplemental material is available for this article. ©RSNA, 2020.

Intracranial chondromas: A histopathologic and molecular study of three cases.

AIMS: Meningeal chondromas constitute a small fraction of central nervous system tumors, with only 61 cases reported in the literature. Somatic mutations of IDH1/2 genes have been described in enchondromas, and, in soft-tissue chondromas, rearrangements of the HMGA2 gene have been reported. The aim of our study was to perform molecular analyses of 3 additional cases and to do a complete review of the literature to better characterize this rare entity. MATERIALS AND METHODS: Here, we report 3 cases of primitive meningeal chondromas in children and young adults. Immunohistochemical analyses for HMGA2 and IDH1R132H, molecular analyses of IDH1/2 mutations, and FISH analysis of the HMGA2 locus were performed. RESULTS: Immunohistochemical analyses of all cases were negative for IDH1R132H and HMGA2 proteins. Molecular analyses failed to reveal IDH1/2 mutations, and FISH analyses did not evidence any HMGA2 rearrangements. Similarly to what is reported in the literature, the 3 meningeal chondromas in this study were benign tumors with no recurrence after complete resection with a follow-up of 85, 46, and 89 months. CONCLUSION: Meningeal chondroma is rare. It affects predominantly young adults and has a good outcome. No molecular alterations have currently been described in this entity.

Differential diagnosis and treatment of enchondromas and atypical cartilaginous tumours of the pelvis: analysis of 21 patients.

INTRODUCTION: Studies focusing on enchondroma and atypical cartilaginous tumour (ACT) of the pelvis are lacking. The purpose of this study was to verify possible clinical and radiological findings with regard to distinguishing enchondromas from ACT of the pelvis. In addition, this study analysed functional and oncological outcomes in patients with enchondromas or ACT of the pelvis treated with curettage or resection. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 21 patients with confirmed enchondroma or ACT of the pelvis treated by curettage or resection from 1985 to 2018. The minimum follow-up was 18 months. The relationship between clinical and radiological factors and tumour type or local recurrence was assessed using Fisher exact test and Mann-Whitney U test. RESULTS: Endosteal scalloping (p = 0.039), tumour size (0.005) and age (0.006) were shown to statistically favour ACT over enchondroma; by contrast, enchondroma and ACT patients had no difference in pain frequency (p = 0.5528). All patients with enchondroma had no local recurrence; in contrast, local recurrence occurred in one patient with ACT, initially treated with resection. The patient with local recurrence had a disease progression with a higher histological grade than the original tumour. Patients treated with curettage had better functional outcomes than patients treated with resection (p = 0.001). DISCUSSION: Endosteal scalloping, tumour size and age could be helpful in the differential diagnosis between enchondroma and ACT of the pelvis. In addition, our study showed that ACT of the pelvis can be safely treated with curettage due to a low risk of local recurrence and better functional results compared with resection. In case of recurrence, we suggest to treat these patients with resection for the risk of disease progression.

The incidence and outcome of chondral tumours as incidental findings on investigation of shoulder pathology.

PURPOSE: The aim of this study is to describe outcomes of incidental chondral tumours in the shoulder referred to our Bone Tumour Unit (BTU). METHODS: Our hospital radiology database was searched using the filtered terms "enchondroma", "low-grade chondral tumour", "chondrosarcoma" with "humerus", "arm", "shoulder", "scapula" and "clavicle". Case note review of results assessed primary reasons for referral, radiological diagnosis, recommended management with subsequent reviews and outcomes, either in clinic or surveillance scan reports. RESULTS: Ninety-nine patients had full case note review, mean age 54.5 years (range 18-84 years). Mean follow-up was 41.7 months (range 1-265 months). Over 50% of patients were referred for shoulder pain. Three patients had high-grade chondrosarcoma. Forty-three patients had interval scans, none showing any changes. Thirty-five patients had surgery for their lesions with one recurrence. Forty-four patients had alternative diagnoses made on clinical and radiological examination. At most recent follow-up, 70% of these patients were asymptomatic after physiotherapy/surgical attention to their alternative diagnoses. CONCLUSIONS: Chondral lesions in the shoulder have low risk of malignant transformation and are rarely responsible for shoulder symptoms. We recommend patients be referred to a dedicated BTU for surveillance if there are any concerning features, but to proceed with management for any alternative diagnosis.

Loss of succinate dehydrogenase B immunohistochemical expression distinguishes pulmonary chondromas from hamartomas.

AIMS: Pulmonary chondromas, which are rare cartilaginous neoplasms that often arise in the setting of Carney triad, are morphologically similar to pulmonary hamartomas, which are much more common. There is evidence that succinate dehydrogenase (SDH) deficiency drives neoplasia in patients with Carney triad, and SDHB immunohistochemistry can be used as a surrogate marker to detect SDH deficiency. The aim of this study was to investigate the utility of SDHB immunohistochemistry in distinguishing pulmonary chondromas from hamartomas. METHODS AND RESULTS: Immunohistochemistry for SDHB (clone 21A11AE7) was performed on histological sections from six cases of pulmonary chondroma and 33 cases of pulmonary hamartoma. SDHB expression was retained in all 33 pulmonary hamartomas, and lost in the majority of evaluable chondromas (five of six). Of the five patients with chondromas showing SDHB loss, four had definitive Carney triad. Most patients with pulmonary hamartomas were older males with small solitary masses, whereas chondromas often presented as multiple masses in young females. CONCLUSION: Loss of SDHB immunohistochemical expression can be useful for differentiating pulmonary chondromas from hamartomas, and potentially identifying patients with Carney triad.

Paragangliomas in Carney-Stratakis Syndrome.

Carney-Stratakis Syndrome (CSS) comprises of paragangliomas (PGLs) and gastrointestinal stromal tumors (GISTs). Several of its features overlap with Carney Triad (CT) - PGLs, GISTs, and pulmonary chondromas. CSS has autosomal dominant inheritance, incomplete penetrance, and greater relative frequency of PGL over GISTs. The PGLs in CSS are multicentric and GISTs are multifocal in all the patients, suggesting an inherited susceptibility and associating the two manifestations. In this review, we highlight the clinical, pathological, and molecular characteristics of CSS, along with its diagnostic and therapeutic implications.

MTNR1B loss promotes chordoma recurrence by abrogating melatonin-mediated ß-catenin signaling repression.

Chordoma is an extremely rare malignant bone tumor with a high rate of relapse. While cancer stem cells (CSCs) are closely associated with tumor recurrence, which depend on its capacity to self-renew and induce chemo-/radioresistance, whether and how CSCs participate in chordoma recurrence remains unclear. The current study found that tumor cells in recurrent chordoma displayed more dedifferentiated CSC-like properties than those in corresponding primary tumor tissues. Meanwhile, MTNR1B deletion along with melatonin receptor 1B (MTNR1B) down-regulation was observed in recurrent chordoma. Further investigation revealed that activation of Gαi2 by MTNR1B upon melatonin stimulation could inhibit SRC kinase activity via recruiting CSK and SRC, increasing SRC Y530 phosphorylation, and decreasing SRC Y419 phosphorylation. This subsequently suppressed ß-catenin signaling and stemness via decreasing ß-catenin p-Y86/Y333/Y654. However, MTNR1B loss in chordoma mediated increased CSC properties, chemoresistance, and tumor progression by releasing melatonin's repression of ß-catenin signaling. Clinically, MTNR1B deletion was found to correlate with patients' survival. Together, our study establishes a novel convergence between melatonin and ß-catenin signaling pathways and reveals the significance of this cross talk in chordoma recurrence. Besides, we propose that MTNR1B is a potential biomarker for prediction of chordoma prognosis and selection of treatment options, and chordoma patients might benefit from targeting MTNR1B/Gαi2/SRC/ß-catenin axis.

A pragmatic approach to the imaging and follow-up of solitary central cartilage tumours of the proximal humerus and knee.

Central cartilage tumours of bone range from the benign enchondroma to the malignant chondrosarcoma. They are an incidental finding in up to 2.8% of routine magnetic resonance imaging (MRI) examinations performed of the shoulder and knee. The purpose of this review is to provide a current appraisal of the imaging and histological challenges of distinguishing enchondroma from low-grade chondrosarcoma. The general radiologist, encountering these lesions in the proximal humerus and around the knee, is introduced to the Birmingham Atypical Cartilage Tumour Imaging Protocol (BACTIP). This provides a guide to the initial assessment and diagnosis, a stepwise imaging follow-up plan, and the indications for onward specialist orthopaedic oncology referral or discharge from follow-up.

Chondroid Tumors as Incidental Findings and Differential Diagnosis between Enchondromas and Low-grade Chondrosarcomas.

Chondroid tumors are a heterogeneous group of neoplasms that all share the production of chondroid matrix. This ranges from a fetal type to mature hyaline cartilage and mirrors its imaging characteristics.The benign chondroid tumors represent some of the most encountered incidental bone lesions, with osteochondroma the most frequent benign bone tumor. Enchondroma is mostly asymptomatic, and yet it is probably the second most common primary bone tumor. Similarly, its malignant counterpart, chondrosarcoma, is the second most common malignant primary bone tumor.The 2013 World Health Organization (WHO) updated this group of tumors, and grade 1 chondrosarcoma was renamed "atypical cartilage tumor" and classified as an intermediate type of tumor, not a malignancy, which better describes its clinical behavior.In this article we summarize changes made in the updated 2013 WHO classification and highlight the diagnostic features differentiating an enchondroma from a low-grade chondrosarcoma. We also describe practical imaging aspects of the remaining chondroid tumors.

Outcome of conservative and surgical treatment of enchondromas and atypical cartilaginous tumors of the long bones: retrospective analysis of 228 patients.

BACKGROUND: Sufficient data on outcome of patients with clinically and radiologically aggressive enchondromas and atypical cartilaginous tumors (ACT) is lacking. We therefore analyzed both conservatively and surgically treated patients with lesions, which were not distinguishable between benign enchondroma and low-grade malignant ACT based upon clinical and radiologic appearance. METHODS: The series included 228 consecutive cases with a follow-up > 24 months to assess radiological, histological, and clinical outcome including recurrences and complications. Pain, satisfaction, functional limitations, and the musculoskeletal tumor society (MSTS) score were evaluated to judge both function and emotional acceptance at final follow-up. RESULTS: Follow-up took place at a mean of 82 (median 75) months. The 228 patients all had comparable clinical and radiological findings. Of these, 153 patients were treated conservatively, while the other 75 patients underwent intralesional curettage. Besides clinical and radiological aggressiveness, most lesions were histologically judged as benign enchondromas. 9 cases were determined to be ACT, while the remaining 7 cases had indeterminate histology. After surgery, three patients developed a recurrence, and a further seven had complications of which six were related to osteosynthesis. Both groups had excellent and almost equal MSTS scores of 96 and 97%, respectively, but significantly less functional limitations were found in the non-surgery group. Further sub-analyses were performed to reduce selection bias. Sub-analysis of histologically diagnosed enchondromas in the surgery group found more pain, less function, and worse MSTS score compared to the non-surgery group. Sub-analysis of smaller lesions (< 4.4 cm) did not show significant differences. In contrast, larger lesions displayed significantly worse results after surgery compared to conservative treatment (enchondromas > 4.4 cm: MSTS score: 94.0% versus 97.3%, p = 0.007; pain 2.3 versus 0.8, p = 0.001). The majority of lesions treated surgically was filled with polymethylmethacrylate bone-cement, while the remainder was filled with cancellous-bone, without significant difference in clinical outcome. CONCLUSION: Feasibility of intralesional curettage strategies for symptomatic benign to low-grade malignant chondrogenic tumors was supported. Surgery, however, did not prove superior compared to conservative clinical and radiological observation. Due to the low risk of transformation into higher-grade tumors and better functional results, more lesions might just be observed if continuous follow-up is assured.

Surface-type chondromyxoid fibroma in an elderly patient: a case report and literature review.

Chondromyxoid fibroma (CMF) is a rare benign bone neoplasm that typically occurs in young adults. Juxtacortical or surface-type CMF are rarer still and we present the case of a surface-type CMF in a 78-year-old woman, with only one other case described in a patient of a similar age previously. This patient was an otherwise healthy woman who presented for evaluation of a palpable lump in the anterior proximal tibia. Initial radiographs obtained demonstrated a focal soft tissue fullness immediately anterior to the anterior cortex of the proximal tibia, which contained faint chondroid-like matrix internally. There was associated scalloping of the anterior tibial cortex. MRI confirmed the presence of a juxtacortical, enhancing lesion. Subsequent excisional biopsy was performed and histopathology demonstrated features, which was consistent with surface-type CMF. At a 6-month follow-up the patient remained free of recurrence. In a patient of this age, paraosteal chondrosarcoma should be excluded. Surface-type CMF, although rare, has been described in older patients and while it is unlikely to feature in a list of differential considerations on initial imaging, awareness of the entity is important.