An evaluation of the diagnostic accuracy of the grade of preoperative biopsy compared to surgical excision in chondrosarcoma of the long bones

Application of microwave ablation assisted degradation therapy in surgical treatment of intramedullary chondrosarcoma of extremities

AIM

Clinical diagnosis and surgical treatment of chondrosarcoma (CS) are continuously improving. The purpose of our study is to evaluate the effectiveness of microwave ablation (MWA) assisted degradation therapy in the surgical treatment of intramedullary chondrosarcoma of the extremities, to provide a new reference and research basis for the surgical treatment of CS.

METHODS

We recruited 36 patients with intramedullary CS who underwent MWA assisted extended curettage. Preoperative patient demographics and clinical data were recorded. Surgery was independently assisted by a medical team. Patients were followed up strictly and evaluated for oncological prognosis, radiological results, limb joint function, pain, and complications.

RESULTS

We included 15 men and 21 women (mean age: 43.5 ± 10.1). The average length of the lesion was 8.1 ± 2.5 cm. Based on preoperative radiographic, clinical manifestations, and pathological results of puncture biopsy, 28 patients were preliminarily diagnosed with CS-grade I and eight patients with CS-grade II. No recurrence or metastasis occurred in the postoperative follow-up. The average Musculoskeletal Tumor Society score was 28.8 ± 1.0, significantly better than presurgery. Secondary shoulder periarthritis and abduction dysfunction occurred in early postoperative stage CS of the proximal humerus in some, but returned to normal after rehabilitation exercise. Secondary bursitis occurred at the knee joint in some due to the internal fixation device used in treatment; however, secondary osteoarthritis and avascular necrosis of the femoral head were not observed. Overall, oncological and functional prognoses were satisfactory.

CONCLUSIONS

The application of MWA assisted degradation therapy in intramedullary CS can achieve satisfactory oncology and functional prognosis, providing a new option for the limited treatment of CS.

Presentation, treatment, and outcomes of chondrosarcoma in young adult patients less than age 50: A case series of ten patients

ABSTRACT

Chondrosarcoma is an aggressive bone tumor typically affecting older adults in the 6th and 7th decade. These tumors often present as painful masses in the pelvis, ribs, and long bones and have certain characteristic features on the imaging leading to the diagnosis. The occurrence of these tumors in the young adult population is a rare condition that is not well described. Often, they may be confused with benign counterparts, enchondroma or osteochondroma, which does not require any treatment and are very common. The aim of this case series was to analyze the patient presentation and radiographic image findings as well as surgical treatment and outcomes of ten young adults with chondrosarcoma over a three-year period. Overall, imaging of these tumors in young adults did not necessarily demonstrate all typical features of chondrosarcomas such as endosteal scalloping, calcifications, lobular growth, and high uptake on whole-body bone scans. One patient in the case series passed away from complications from dedifferentiated chondrosarcoma, and nine patients have recovered with no local recurrence.

The influence of site on the incidence and diagnosis of solitary central cartilage tumours of the femur. A 21st century perspective

OBJECTIVE

To determine the incidence of central cartilage tumours (CCTs) in the femur and the impact of site (proximal, mid and distal thirds) on tumour grade. To compare study results with historically published data.

MATERIALS AND METHODS

Retrospective review of solitary CCTs arising in the femur over the past 13 years. Data collected included location (proximal, mid and distal thirds) and final diagnosis in terms of tumour grade based on imaging features ± histology. Case material collected from three bone tumour textbooks provided historical data.

RESULTS

430 solitary CCTs were included in the femur. 73% cases arose in the distal, 3.7% in the mid and 23% in the proximal femur. The ratio of "benign" (combining enchondroma and atypical cartilaginous tumour (ACT)) to higher grade chondrosarcoma (CS) was 11:1 in the distal, 1:1 in the mid and 1:1.5 in the proximal femur, the distribution of benign to malignant tumours being significantly different between the regions (F test, p < 0.05). Comparison with historical data showed a reversal of the benign (enchondroma) to malignant (ACT and higher grade CS) of 30%:70%-84%:16% in the current series.

CONCLUSIONS

The site of origin of a CCT in the femur has an impact on final diagnosis with CS uncommon in the distal as compared with the mid and proximal femur. This is in contradistinction to historical data where the incidence of CS exceeded that of enchondroma at all sites.

Peripheral and periosteal chondrosarcoma: MRI-pathological correlation in 58 cases

OBJECTIVE

To determine whether MRI can distinguish atypical cartilaginous tumour/grade 1 peripheral/periosteal chondrosarcoma (ACT/Gd1 PP-CS) from high-grade peripheral/periosteal chondrosarcoma (HG-PP-CS) or dedifferentiated peripheral/periosteal chondrosarcoma (DD-PP-CS).

MATERIALS AND METHODS

Retrospective review of patients diagnosed between January 2007 and December 2020 who had undergone resection of PP-CS. Data collected included age, sex, and skeletal location. Histological tumour grades based on surgical resection were classified as ACT/grade 1 PP-CS, HG-PP-CS, or DD-PP-CS. A variety of MRI features were reviewed independently by 2 musculoskeletal radiologists blinded to final diagnosis and compared between the 3 groups. For statistical analysis, HG-PP-CS and DD-PP-CS were combined.

RESULTS

Fifty-eight patients fulfilled the inclusion criteria, 31 (53%) males and 27 (47%) females with a mean age at diagnosis of 46.1 years (range 11-83 years), 14 (24%) of whom had an underlying diagnosis of diaphyseal aclasis. Forty-one (70.7%) cases were peripheral and 17 (29.3%) periosteal, 38 (66%) involving the flat bones, 15 (26%) the major long bones, 3 (5%) the spine, and 2 (3%) the bones of the hands and feet. Final histology revealed 33 (57%) ACT/Gd1-PP-CS, 18 (31%) HG-PP-CS, and 7 (12%) DD-PP-CS. Periosteal tumours were 16 times more likely to be HG/DD-CS compared to peripheral tumours (p < 0.001). Intra-medullary tumour extension was predictive of HG/DD-CS (p = 0.004) for both tumour types, while cap thickness (p = 0.04) and a diffuse cap type (p = 0.03) were differentiating features of low-grade and high-grade peripheral CS.

DISCUSSION

A variety of features can help differentiate low-grade from high-grade peripheral/periosteal CS, the most significant being origin from the bone surface.

A Radiological Scoring System for Differentiation between Enchondroma and Chondrosarcoma

Simple Summary

Background: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. Methods: To evaluate the diagnostic usefulness of radiological findings for differentiation between enchondromas and chondrosarcomas, correlations between various radiological findings and final diagnoses were investigated. Based on the correlations, a scoring system combining these findings was developed. Results: In a cohort of 81 patients, periosteal reaction on X-ray, endosteal scalloping and cortical defect on CT, extraskeletal mass, multilobular lesion, abnormal signal in adjacent tissue on MRI, and increased uptake in bone scan and thallium scan was significantly correlated with final diagnoses. Based on the correlations, a radiological scoring system combining radiological findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and chondrosarcomas were 88%, 89%, and 88%, respectively. Conclusion: Comprehensive assessment combining radiological findings is recommended to differentiate between enchondromas and ACTs/chondrosarcomas.

Abstract

Background: It is challenging to differentiate between enchondromas and atypical cartilaginous tumors (ACTs)/chondrosarcomas. In this study, correlations between radiological findings and final diagnosis were investigated in patients with central cartilaginous tumors. Methods: To evaluate the diagnostic usefulness of radiological findings, correlations between various radiological findings and final diagnoses were investigated in a cohort of 81 patients. Furthermore, a new radiological scoring system was developed by combining radiological findings. Results: Periosteal reaction on X-ray (p = 0.025), endosteal scalloping (p = 0.010) and cortical defect (p = 0.002) on CT, extraskeletal mass (p < 0.001), multilobular lesion (p < 0.001), abnormal signal in adjacent tissue (p = 0.004) on MRI, and increased uptake in bone scan (p = 0.002) and thallium scan (p = 0.027) was significantly correlated with final diagnoses. Based on the correlations between each radiological finding and postoperative histological diagnosis, a radiological scoring system combining these findings was developed. In another cohort of 17 patients, the sensitivity, specificity, and accuracy of the radiological score rates for differentiation between enchondromas and ACTs/chondrosarcomas were 88%, 89%, and 88%, respectively (p = 0.003). Conclusion: Radiological assessment with combined radiological findings is recommended to differentiate between enchondromas and ACT/chondrosarcomas.

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.

The changing face of central chondrosarcoma of bone. One UK-based orthopaedic oncology unit's experience of 33 years referrals

AIM

To ascertain the changing incidence over time of the three commonest primary sarcomas of bone. Data obtained with particular reference to central chondrosarcoma from the annual referral rate to a large UK-based specialist orthopaedic oncology unit. To discuss how the "barnyard pen" analogy of cancers previously applied to certain commoner cancers can also be applicable to central chondrosarcoma (CS) of bone.

MATERIALS AND METHODS

A retrospective review was conducted of a computerised database identifying all central cartilage tumours (CCT) of bone, including enchondroma and CS subtypes, between 1985 and 2018. These were compared with the referrals of the other two commonest primary sarcomas of bone, osteosarcoma and Ewing sarcoma.

RESULTS

There was a total of 1507 CS showing a 68% overall increase in annual referral rate/incidence over the study period. 68% cases were the borderline malignant lesions now known as atypical cartilaginous tumour (ACT). The annual referral rate/incidence of this entity increased by 194% over the 30 years. Whereas, the annual referral rate/incidence for osteosarcoma and Ewing sarcoma was static for the past 20 years.

CONCLUSION

The annual incidence of central CS of bone showed a marked increase over the 33-year period as compared with both osteosarcoma and Ewing sarcoma. This is especially in the ACT category and is thought to be due to the increased provision of MRI scanning flagging up a rise in incidental findings. The spectrum of CCTs from benign to highly malignant elegantly fits the "barn yard" pen analogy and could prove useful as an explanatory tool for patients and clinicians unfamiliar with these diseases.

The role of imaging in differentiating low-grade and high-grade central chondral tumours

Chondrosarcoma is a malignant cartilage matrix-producing tumour. Those arising de novo are called primary chondrosarcomas and are the second commonest primary malignant bone tumours. Numerous types of primary chondrosarcoma exist, namely conventional central (intramedullary), periosteal (juxta-cortical), clear cell, mesenchymal, and dedifferentiated. The biologic aggressiveness, prognosis and thus management of chondrosarcoma are dependent on the histological sub-type and grade. Accurate pre-operative diagnosis is therefore essential in determining management and outcome which requires a multidisciplinary approach taking into account clinical features, imaging findings and histopathology. In this review, we present the pertinent multimodality imaging features which aid in the differentiation of low-grade and high-grade conventional central chondrosarcoma.

The importance of MRI review following the diagnosis of atypical cartilaginous tumour using image-guided needle biopsy

OBJECTIVE

To evaluate the role of pre-biopsy MRI for management planning in patients with atypical cartilaginous tumours (ACT) diagnosed on image-guided core needle biopsy (IGCNB).

MATERIALS AND METHODS

Retrospective review of patients diagnosed with ACT of the appendicular skeleton based on IGCNB who subsequently underwent surgical curettage or resection. Data collected included age, sex, skeletal location and surgical histology classified as ACT, high-grade chondrosarcoma (HG-CS) and dedifferentiated chondrosarcoma (DD-CS). Pre-biopsy MRI studies were reviewed independently by 2 radiologists blinded to surgical histology results and graded as ACT, HG-CS and DD-CS based on MRI features.

RESULTS

The study included 24 males and 28 females (mean age 42.1 years; range 9-76 years). One patient had 2 lesions treated, making a total of 53 lesions. Tumours were located in the femur in 21 cases, humerus in 17, tibia in 9, radius in 4 and ulna and fibula in 1 each. Surgical histology was ACT in 41 cases, HG-CS in 10 and DD-CS in 2, indicating mismatch between IGCNB and surgical histology in 12/53 cases (22.6%). Predicted MRI grade for the 2 readers was ACT in 39 cases each, HG-CS in 13 and 14 cases and DD-CS in 1 and 0 cases. Sensitivity, specificity and accuracy of MRI for predicting HG-CS/DD-CS were 91%, 93% and 92%, respectively. Inter-observer correlation was very good (kappa = 0.94).

DISCUSSION

Review of MRI findings in patients with ACT diagnosed on IGCNB is vital for identifying patients with a HG-CS/DD-CS and is recommended when planning surgical management or considering repeat IGCNB.

Diagnostic accuracies of intraoperative frozen section and permanent section examinations for histological grades during open biopsy of bone tumors

BACKGROUND

A histological diagnosis obtained from an intraoperative frozen section (FS) during biopsy confirms the adequacy of tumor tissue in the specimen. However, some cases show a discrepancy among the intraoperative FS diagnosis, permanent section (PS) diagnosis of the biopsy specimen, and the final diagnosis of the excised tumor specimen. In this study, we retrospectively investigated the diagnostic accuracy of the FS and PS for different types of bone tumors.

METHODS

This study included 377 patients with 411 bone tumors who underwent tumor excision after an open biopsy with intraoperative FS diagnosis. FS, PS, and final diagnoses of the patients were classified into benign tumors/tumor-like lesions, intermediate malignancies, and malignant tumors. To assess diagnostic accuracy, the histological grades in FS and PS diagnoses were compared with those in the final diagnoses.

RESULTS

The overall diagnostic accuracies of FS and PS were 93% and 97%, respectively. The accuracy of FS and PS for histological grade was 84% and 93% for chondrogenic tumors, 90% and 96% for osteogenic tumors, 97% and 98% for osteoclastic giant cell-rich tumors, 100% and 100% for tumors of undefined neoplastic nature, and 95% and 99% for other bone tumors, respectively.

CONCLUSION

These data suggest that surgical planning based on PS diagnosis is recommended for chondrogenic and osteogenic tumors.

Chondral tumours: discrepancy rate between needle biopsy and surgical histology

OBJECTIVE

To determine the reliability of image-guided core needle biopsy (IGCNB) for the diagnosis and grading of chondral tumours of bone compared with surgical histology.

MATERIALS AND METHODS

Retrospective review of patients with a chondral tumour of bone who underwent IGCNB and surgical resection between January 2007 and December 2017. Data collected included age, sex, skeletal location, technique used for IGCNB, IGCNB result including histological grade and comparison with surgical histology.

RESULTS

A total of 237 patients were included (135 males and 102 females with mean age 53.7 years, range 9-89 years). A total of 174 IGCNBs were CT-guided, 57 ultrasound-guided and 6 fluoroscopic-guided. Two hundred thirty-six of 237 (99.6%) IGCNBs were diagnostic for a chondral tumour, although grade could not be determined in 13 (5.5%) due to necrosis. A positive correlation for tumour grade between IGCNB and surgical histology was achieved in 181 cases (76.4%). In 36 patients (15.2%), IGCNB under-graded the tumour, while in 6 (2.5%), IGCNB over-graded the tumour. Discrepancy between IGCNB and surgical histology was significantly greater for surface/peripheral lesions (p = 0.02) and lesions arising from the flat bones or spine (p = 0.002).

DISCUSSION

IGCNB can achieve a diagnosis of a chondral tumour in a high proportion of cases when compared with final diagnosis from surgical resection specimens. However, correlation of tumour grade between IGCNB and resection histology is less reliable with discordance seen in almost one-quarter of cases, most commonly at non-appendicular sites. Therefore, IGCNB results should not be considered in isolation of imaging and clinical features when planning surgical management.

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.

Treatment strategies for central low-grade chondrosarcoma of long bones: a systematic review of the literature and meta-analysis

The need for wide local excision (WLE) versus intralesional (IL) treatment of low-grade chondrosarcomas (CS) of the appendicular skeleton remains controversial. We sought to perform a systematic review and meta-analysis to compare different conventional types of surgical treatments for grade I CS in terms of: (1) rate of local recurrence (LR) and metastases, (2) functional outcome as measured by the Musculoskeletal Tumor Society (MSTS) score, (3) complication rate. Eighteen studies enrolling 695 patients met our criteria. Studies reported on WLE versus IL treatment (n = 7), and IL treatment with or without different adjuvants (N = 11). The LR rate was not significantly different between WLE and IL treatment (OR 2.31; 95% CI, 0.85-6.2; P = 0.1). On the contrary, complication rates were significantly lower in favor of IL treatment (OR 2.27; 95% CI, 0.07-0.72; P = 0.012). The mean reported MSTS score ranged from 21.8 to 28.2 for WLE and from 26.5 to 29.7 for IL treatment, with a significant difference in favor of IL treatment. IL treatment as an alternative to WLE does not greatly increase the risk of LR or metastasis and has lower complication rates with better functional scores. In light of the retrospective nature of the studies available, our findings should be interpreted with caution.

F-18 FDG PET differentiation of benign from malignant chondroid neoplasms: a systematic review of the literature

INTRODUCTION

Discriminating among benign chondroid tumors, low-grade chondrosarcomas, and grade 2/3 chondrosarcomas is frequently difficult with standard imaging modalities. We systematically reviewed the literature to determine the performance of PET-CT in making this distinction.

METHODS

A systematic review was performed identifying 811 PubMed- and Embase-indexed articles containing combinations of "chondrosarcoma," "enchondroma," "chondroid," "cartilage" and "PET/CT," "PET," "positron." Eight articles including 166 lesions were included. Age, gender, tumor size, histologic grade, and SUVmax values were extracted for individual lesions when possible and otherwise recorded as aggregated data. Comparisons in SUVmax among benign, low-grade, and intermediate-/high-grade chondroid neoplasms were made.

RESULTS

Individual SUVs were available for 101 lesions; 65 additional lesions were reported as aggregated data. There were 101 malignant and 65 benign tumors. Benign tumors were seen more frequently in females (p = 0.04, Fischer's exact test), but malignancy was not associated with age or lesion size. SUVmax was lower for benign (1.6 ± 0.7) than malignant tumors (4.4 ± 2.5) (p < 0.0001, t-test). SUVmax was lower for grade 0/1 (2.0 ± 0.7) than grade 2/3 (6.0 ± 3.2) (p < 0.0001, t-test). Increasing SUVmax correlated with higher grade chondroid tumors (Spearman's rank, ρ = 0.78). SUVmax ≥4.4 was 99% specific for grade 2/3 chondrosarcoma.

CONCLUSIONS

SUVmax correlates with histologic grade in intraosseous chondroid neoplasms; very low SUVmax supports a diagnosis of benign tumor, while elevated SUVmax is suggestive of higher grade chondrosarcoma.

Is Needle Biopsy Clinically Useful in Preoperative Grading of Central Chondrosarcoma of the Pelvis and Long Bones?

BACKGROUND

Central chondrosarcoma of bone is graded on a scale of 1 to 3 according to histological criteria. Clinically, these tumors can be divided into low-grade (Grade 1) and high-grade (Grade 2, Grade 3, and dedifferentiated) chondrosarcomas. Although en bloc resection has been the most widely used treatment, it has become generally accepted that in selected patients with low-grade chondrosarcomas of long bones, curettage is safe and effective. This approach requires an accurate preoperative estimation of grade to avoid under- or overtreatment, but prior reports have indicated that both imaging and biopsy do not always give an accurate prediction of grade.

QUESTIONS/PURPOSES

(1) What is the concordance of image-guided needle preoperative biopsy and postoperative grading in central (intramedullary) chondrosarcomas of long bones, and how does this compare with the concordance of image-guided needle preoperative biopsy and postoperative grading in central pelvic chondrosarcomas? (2) What is the concordance of preoperative image-guided needle biopsy and postoperative findings in differentiating low-grade from high-grade central chondrosarcomas of long bones, and how does this compare with the concordance in central pelvic chondrosarcomas?

METHODS

Between 1997 and 2014, in our institution, we treated 126 patients for central chondrosarcomas located in long bones and the pelvis. Of these 126 cases, 41 were located in the pelvis and the remaining 85 cases were located in long bones. This study considers 39 (95%) and 40 (47%) of them, respectively. We included all cases in which histological information was complete regarding preoperative and postoperative tumor grading. We excluded all cases with incomplete data sets or nondiagnostic preoperative biopsies. To evaluate the needle biopsy accuracy, we compared the histological tumor grade, obtained from the preoperative biopsy, with the final histological grade obtained from the postoperative surgical specimen. The weighted and nonweighted kappa statistics were used to evaluate the agreement.

RESULTS

Concordance between the preoperative biopsy and the final pathological analysis in terms of histological grade was much higher in long-bone chondrosarcoma than in pelvic chondrosarcoma (83% [33 of 40] versus 36% [14 of 39]; odds ratio, 8, 48). Likewise, the weighted kappa coefficients were higher in long-bone chondrosarcoma than in pelvic chondrosarcoma for the determination of histological grade (0.63; 95% confidence interval [CI], 0.34-0.91 versus 0.12; -0.32 to 0.57; p < 0.001). When categorizing the lesions as low grade or high grade, concordance between the preoperative biopsy and the final pathological analysis was much higher in long-bone chondrosarcoma than in pelvic chondrosarcoma (90% [36 of 40] versus 67% [26 of 39]; odds ratio, 4, 5). Likewise, the weighted kappa coefficients were higher in long-bone chondrosarcoma than in pelvic chondrosarcoma (0.73; 95% CI, 0.51-0.94 versus 0.26; 0.04-0.48; p < 0.001).

CONCLUSIONS

Image-guided needle biopsy, when performed by a specialist radiologist and evaluated by an experienced bone pathologist, is a useful tool in determining the histological grade of long-bone chondrosarcomas allowing identification of true low-grade tumors. The histological grade should be correlated with imaging and the clinical presentation, but under these circumstances, experienced tumor surgeons may use this information in planning surgical treatment. The same appears not to be true for pelvic lesions, in which histological grade established by needle biopsy should be interpreted with caution.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Is PET-CT an accurate method for the differential diagnosis between chondroma and chondrosarcoma?

The differential diagnosis between chondroma and intraosseous chondrosarcoma is based on imaging and clinical exams, but only a biopsy can confirm diagnosis. The aim of this study was to evaluate the value of PET–CT in differentially diagnosing chondroma and chondrosarcoma. From October 2009 to May 2015, 36 patients with cartilaginous bone lesions in the extremities, 12 (33.3 %) men and 24 (66.6 %) women, were prospectively included in the study. Patients ranged in age from 21 to 68 years, with a mean age of 44 years. Lesions were located in the long bones: in the proximal humerus in 26 (72.2 %) patients, in the femoral shaft in 1 (2.7 %), in the distal femur in 7 (19.4 %), and in the proximal tibia in 2 (5.5 %). The SUVmax value of 2.0 was used to separate between patients submitted to surgery and patients submitted to observation. Among the 36 patients studied, 17 (47.2 %) had SUVmax ≤ 2.0, and they were diagnosed as chondroma and they were treated conservatively. Follow-up ranged from 14 to 76 months, averaging 38 months. Nineteen (52.7 %) patients with SUVmax >2.0 were diagnosed as chondrosarcoma and underwent surgery. The area of the curve, calculated considering the SUV variable as numeric, is estimated in 0.966, with a 95 % confidence interval from 0.906 to 1.000. To evaluate the sensitivity, specificity and positive/negative predictive values, it was built a 2 × 2 table. Significance was set at p < 0.05. According the criteria of maximum sensitivity and specificity, the cut point suggested to SUVmax was 2.2. If we consider this point, it is possible to identify 19 of 36 positive cases to chondroma (52.8 %), it means, all chondrosarcomas of the series. We concluded that PET–CT can be used as an objective and quantitative method of differentiating between chondromas and chondrosarcomas located within the long bones. It represents a complementary examination to standard imaging (X-ray, scintigraphy, CT and MRI) and pathological exams. The SUVmax between 2.0 and 2.2 would be a range area between chondroma and chondrosarcoma and this range can be of value, among others exams, in decide the best treatment for patients with cartilaginous lesions in long bones.

Level of evidence Level I—diagnostic study—prospectively investigating a diagnostic test using a universally applied “gold” standard.

[Benign cartilage tumors. What should I do with incidental findings?]

BACKGROUND

The majority of benign bone tumors are cartilage tumors. Most common are enchondroma and osteochondroma. Often they represent incidental findings in radiological diagnostics. Thus, the incidence of cartilage tumors is unknown, as most of them are never diagnosed due to the absence of any symptoms.

OBJECTIVES

This article describes the diagnostic and therapeutic approach of benign cartilage tumors, focusing on incidental findings.

METHODS

The current knowledge and our own experience in the diagnostics and treatment of benign condroid tumors are presented.

RESULTS

As enchondroma represent most often the classic incidental finding without any symptoms or clinical findings, osteochondroma are often diagnosed in young patients by clinical examination showing a painless swelling that can increase in size according to skeletal growth. Most of these asymptomatic enchondroma and osteochondroma are so called "leave me alone lesions" and do not need any treatment, while other benign tumors (e.g., atypical cartilage tumors, chondroblastoma, chondromyxoidfibroma or osteochondroma with a cartilage cap of over 2 cm) need surgical treatment. These active or local aggressive tumors must be differentiated from the "leave me alone lesions". Additionally, patients with syndromes like Ollier disease (enchondromatosis), Maffucci syndrome or hereditary multiple exostosis must be examined and checked carefully as malignant degradation is possible.

CONCLUSION

As most cartilage tumors are benign and remain benign, inappropriate diagnostics or operative treatment just to provide security is obsolete. Plain X-ray is often enough for follow-up and other modalities only become necessary when symptoms occur.