[A case of bronchoscopic treatment for endobronchial chondroma].

Endobronchial chondroma is a rare benign bronchial tumor that originates from bronchial cartilage. As the disease progresses, it can obstruct the airway and cause clinical symptoms such as fever and cough. It is difficult to detect Endobronchial chondroma on a Chest X-ray, but chest CT can provide a more accurate diagnosis. Bronchoscopy is an effective means of diagnosing and treating this disease, and the diagnosis of the disease still depends on the pathological results of the biopsy. Currently, most cases of Endobronchial chondroma are treated by bronchoscopic resection or by surgery. Treatment should be based on the size, type and location of the tumor. As long as the diagnosis of Endobronchial chondroma is confirmed, it should be removed as soon as possible to avoid obstructive pneumonia, atelectasis or irreversible damage to lung tissue caused by tumor compression of the bronchi. This article reported a case of Endobronchial chondroma in a 19-year-old man whose main clinical manifestations were fever, cough and chest pain, with no apparent improvement after antibiotic treatment. Chest CT showed consolidation and atelectasis of the left upper lobe, and bronchial foreign body was considered by bronchoscopy in another hospital. However, the patient did not improve significantly after the foreign body was removed. After admission, the patient was considered to have left pulmonary obstructive pneumonia due to bronchial foreign body. A white tough foreign body was seen under bronchoscopy, which was too seriously adhered with the bronchus to be removed as a whole. After two bronchoscopic interventional treatments, the foreign body was successfully removed, and the bronchial lumen blocked by the foreign body was restored to patency. Pathology confirmed the diagnosis of endobronchial chondroma. The patient's symptoms improved and he was subsequently discharged. To date, the patient's symptoms of fever, cough, or chest pain have never recurred, and there is no obvious abnormality on repeat chest CT. This case provides an empirical reference for the diagnosis and treatment of endobronchial chondroma.

Clinical and radiological response of Maffucci related enchondromas to mutant IDH1 inhibitor Ivosidenib.

Ollier Disease (OD) and Maffucci syndrome (MS) is a rare bone disorder that affects the growth and development of the bones, with an estimated prevalence of 1 in 100,000 people. It is associated with somatic mosaicism of isocitrate dehydrogenase-1 (IDH1) or 2 (IDH2) pathogenic variants. Ivosidenib is indicated for the treatment of acute myeloid leukemia and locally advanced or metastatic cholangiocarcinoma and is currently investigated in low-grade glioma with a susceptible isocitrate dehydrogenase-1 (IDH1) pathogenic variant, but its effects in patients with OD or MS are unknown. We here report the first case of a patient with MS who was treated with Ivosidenib for recurrent IDH-1 mutated glioma. Besides the stabilization of the tumor size, the patient observed significant improvement in his enchondromas that became stiffer, with reduced pain, and significant modification of the mineralization of the enchondromas observed on X-rays. This first case report provides hope for the medical management of patients suffering because of OD or MS. Future clinical research is urgently needed to evaluate long-term benefit risk profile of IDH inhibitors in these rare diseases.

CT radiomics-based machine learning model for differentiating between enchondroma and low-grade chondrosarcoma.

It may be difficult to distinguish between enchondroma and low-grade malignant cartilage tumors (grade 1) radiologically. This study aimed to construct machine learning models using 3D computed tomography (CT)-based radiomics analysis to differentiate low-grade chondrosarcoma from enchondroma. A total of 30 patients with enchondroma and 26 with chondrosarcoma were included in this retrospective study. Tumor volume segmentation was manually performed by 2 musculoskeletal radiologists. In total, 107 radiomic features were obtained for each patient. The intraclass correlation coefficient was used to assess interobserver reliability and estimate the absolute agreement between the 2 radiologists. Algorithm-based information gain was used as a feature reduction method, and the 5 most important features were detected. For classification, 7 machine learning models were utilized. Classification was carried out using either all features or 5 features. There was good to excellent agreement between the 2 radiologists for the 107 features of each patient. Therefore, a dataset containing 107 features was used for machine learning classification. When assessed based on area under curve (AUC) values, classification using all features revealed that naive Bayes was the best model (AUC = 0.950), while classification using 5 features revealed that random forest was the best model for differentiating chondrosarcoma from enchondroma (AUC = 0.967). In conclusion, machine learning models using CT-based radiomics analysis can be used to differentiate between low-grade chondrosarcoma and enchondroma.

Incidental 68 Ga-PSMA Uptake in the Benign Enchondroma-A Rare Finding on 68 Ga-PSMA PET/CT.

ABSTRACT: 68 Ga-PSMA (prostate-specific membrane antigen)-HBED-CC (N,N'-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N'-diacetic acid) PET/CT is the new advancement in oncological imaging. However, false-positive uptake can be seen in benign lesions on 68 Ga-PSMA PET/CT. We describe a rare case of intense 68 Ga-PSMA uptake in an enchondroma confirmed on MRI.

Enchondroma on Bone Scan and PSMA PET/CT in a Patient With Prostate cancer.

ABSTRACT: A 54-year-old man with Gleason 9 prostate cancer with reported nodal and skeletal metastases was referred to us. Outside hospital reports described abnormal left proximal humerus activity on bone scan concerning for metastasis; however, concurrent PSMA PET/CT did not show activity in this lesion. Further review of the PET/CT images revealed characteristic features of enchondroma in the left humeral lesion.

Actualización de los tumores cartilaginosos según la clasificación de la OMS de 2020 / Update of cartilaginous tumours according to the WHO classification 2020

Los tumores cartilaginosos son un grupo amplio y heterogéneo de neoplasias caracterizadas por la presencia de una matriz condroide que presenta crecimiento lobular y patrones de calcificación en arcos y anillos o en palomitas de maíz. En RM destaca su hiperintensidad en las secuencias potenciadas en T2, y en las imágenes poscontraste, un relace lobulado o septal. En la clasificación de 2020 de la OMS, los tumores de estirpe condral se clasifican en benignos, intermedios o malignos. A pesar de los avances tecnológicos, siguen suponiendo un reto tanto para el radiólogo como para el patólogo, siendo la principal dificultad la diferenciación entre los tumores benignos y malignos, razón por la que requieren un abordaje multidisciplinar. Este trabajo recoge los principales cambios introducidos en la actualización de 2020, describe las características de imagen de los principales tumores cartilaginosos y proporciona las claves radiológicas para diferenciar entre tumores benignos y malignos.(AU)

Cartilaginous tumours are a large and heterogeneous group of neoplasms characterised by the presence of a chondroid matrix, with lobular growth and arcuate, ring-like or popcorn-like calcification patterns. MRI shows hyperintensity in T2-weighted sequences and a lobulated or septal relief in postcontrast images. In the WHO 2020 classification, chondral tumours are classified as benign, intermediate or malignant. Despite technological advances, they continue to pose a challenge for both the radiologist and the pathologist, being the main difficulty the differentiation between benign and malignant tumours, which is why they require a multidisciplinary approach. This paper describes the main changes introduced in the 2020 update, describes the imaging characteristics of the main cartilaginous tumours and provides the radiological keys to differentiate between benign and malignant tumours.(AU)

A retrospective external validation study of the Birmingham Atypical Cartilage Tumour Imaging Protocol (BACTIP) for the management of solitary central cartilage tumours of the proximal humerus and around the knee.

OBJECTIVES: This study aimed to externally validate the Birmingham Atypical Cartilage Tumour Imaging Protocol (BACTIP) recommendations for differentiation/follow-up of central cartilage tumours (CCTs) of the proximal humerus, distal femur, and proximal tibia and to propose BACTIP adaptations if the results provide new insights. METHODS: MRIs of 123 patients (45 ± 11 years, 37 men) with an untreated CCT with MRI follow-up (n = 62) or histopathological confirmation (n = 61) were retrospectively/consecutively included and categorised following the BACTIP (2003-2020 / Ghent University Hospital/Belgium). Tumour length and endosteal scalloping differences between enchondroma, atypical cartilaginous tumour (ACT), and high-grade chondrosarcoma (CS II/III/dedifferentiated) were evaluated. ROC-curve analysis for differentiating benign from malignant CCTs and for evaluating the BACTIP was performed. RESULTS: For lesion length and endosteal scalloping, ROC-AUCs were poor and fair-excellent, respectively, for differentiating different CCT groups (0.59-0.69 versus 0.73-0.91). The diagnostic performance of endosteal scalloping and the BACTIP was higher than that of lesion length. A 1° endosteal scalloping cut-off differentiated enchondroma from ACT + high-grade chondrosarcoma with a sensitivity of 90%, reducing the potential diagnostic delay. However, the specificity was 29%, inducing overmedicalisation (excessive follow-up). ROC-AUC of the BACTIP was poor for differentiating enchondroma from ACT (ROC-AUC = 0.69; 95%CI = 0.51-0.87; p = 0.041) and fair-good for differentiation between other CCT groups (ROC-AUC = 0.72-0.81). BACTIP recommendations were incorrect/unsafe in five ACTs and one CSII, potentially inducing diagnostic delay. Eleven enchondromas received unnecessary referrals/follow-up. CONCLUSION: Although promising as a useful tool for management/follow-up of CCTs of the proximal humerus, distal femur, and proximal tibia, five ACTs and one chondrosarcoma grade II were discharged, potentially inducing diagnostic delay, which could be reduced by adapting BACTIP cut-off values. CLINICAL RELEVANCE STATEMENT: Mostly, Birmingham Atypical Cartilage Tumour Imaging Protocol (BACTIP) assesses central cartilage tumours of the proximal humerus and the knee correctly. Both when using the BACTIP and when adapting cut-offs, caution should be taken for the trade-off between underdiagnosis/potential diagnostic delay in chondrosarcomas and overmedicalisation in enchondromas. KEY POINTS: • This retrospective external validation confirms the Birmingham Atypical Cartilage Tumour Imaging Protocol as a useful tool for initial assessment and follow-up recommendation of central cartilage tumours in the proximal humerus and around the knee in the majority of cases. • Using only the Birmingham Atypical Cartilage Tumour Imaging Protocol, both atypical cartilaginous tumours and high-grade chondrosarcomas (grade II, grade III, and dedifferentiated chondrosarcomas) can be misdiagnosed, excluding them from specialist referral and further follow-up, thus creating a potential risk of delayed diagnosis and worse prognosis. • Adapted cut-offs to maximise detection of atypical cartilaginous tumours and high-grade chondrosarcomas, minimise underdiagnosis and reduce potential diagnostic delay in malignant tumours but increase unnecessary referral and follow-up of benign tumours.

Extraskeletal chondroma of the toe in a child with DICER1 tumor predisposition syndrome: support for a dominant negative mechanism.

DICER1 tumor predisposition syndrome is a pleiotropic disorder that gives rise to various mainly pediatric-onset lesions. We report an extraskeletal chondroma (EC) of the great toe occurring in a child who, unusually, carries a germline "hotspot" missense DICER1 variant rather than the more usual loss-of-function (LOF) variant. No heterozygous LOF allele was identified in the EC. We demonstrate this variant impairs 5p cleavage of precursor-miRNA (pre-miRNA) and competes with wild-type (WT) DICER1 protein for pre-miRNA processing. These results suggest a mechanism through which a germline RNase IIIb variant could impair pre-miRNA processing without complete LOF of the WT DICER1 allele.

SPECT/CT Radiomics for Differentiating between Enchondroma and Grade I Chondrosarcoma.

This study was performed to assess the value of SPECT/CT radiomics parameters in differentiating enchondroma and atypical cartilaginous tumors (ACTs) located in the long bones. Quantitative HDP SPECT/CT data of 49 patients with enchondromas or ACTs in the long bones were retrospectively reviewed. Patients were randomly split into training (n = 32) and test (n = 17) data, and SPECT/CT radiomics parameters were extracted. In training data, LASSO was employed for feature reduction. Selected parameters were compared with classic quantitative parameters for the prediction of diagnosis. Significant parameters from training data were again tested in the test data. A total of 12 (37.5%) and 6 (35.2%) patients were diagnosed as ACTs in training and test data, respectively. LASSO regression selected two radiomics features, zone-length non-uniformity for zone (ZLNUGLZLM) and coarseness for neighborhood grey-level difference (CoarsenessNGLDM). Multivariate analysis revealed higher ZLNUGLZLM as the only significant independent factor for the prediction of ACTs, with sensitivity and specificity of 85.0% and 58.3%, respectively, with a cut-off value of 191.26. In test data, higher ZLNUGLZLM was again associated with the diagnosis of ACTs, with sensitivity and specificity of 83.3% and 90.9%, respectively. HDP SPECT/CT radiomics may provide added value for differentiating between enchondromas and ACTs.

Encondroma osificado en fémur. Una localización atípica. A propósito de un caso / Ossified enchondroma in femur. An atypical location. Case study

Presentamos el caso de un hombre de 61 años en el que se halló de forma incidental un encondroma a nivel proximal de fémur. Tras seguimiento, se observó la estabilidad de la lesión. El encondroma es un tumor de origen cartilaginoso benigno. Se localiza principalmente en las falanges de las manos y los pies, aunque puede observarse en húmero o fémur. Por lo general, es una lesión asintomática y se halla de manera incidental. En las radiografías suelen verse lesiones redondeadas bien definidas con radiolucidez central. Se recomienda el seguimiento con radiografías seriadas para comprobar la progresión o estabilidad de la lesión y hacer su diagnóstico diferencial con el condrosarcoma.(AU)

We report the case of a 61-year-old man in whom an enchondroma was incidentally detected at the proximal level of the femur. After follow-up the lesion was stable. Enchondroma is a benign cartilaginous tumor. It is located mainly in the phalanges of the hands and feet, although it can be seen in the humerus or femur. It is usually an asymptomatic lesion, found incidentally. On x-rays, well-defined round lesions with central radiolucency are usually observed. Follow-up with serial x-rays is recommended to verify the lesion’s course or stability and make its differential diagnosis with chondrosarcoma.(AU)

Cemented K-wire external fixation in juxta-articular enchondroma-related phalangeal pathological fracture.

PURPOSE: This study aimed to introduce a technique of external fixation using a combination of bone cement and K-wires, to treat pathological fractures related to solitary digital enchondroma close to the finger joints. METHODS: From October 2015 to January 2021, 21 patients (8 males and 13 females) with acute pathological fracture due to solitary digital enchondroma close to the finger joints were treated with cemented K-wire external fixators. Mean age was 32 (19-51) years. The digits involved were the index (n = 4), long (n = 4), ring (n = 6), and little (n = 7) fingers. Time to bone healing and complications were assessed. At final follow-up, active range of motion, grip strength and key pinch strength of the tumor-involved and contralateral healthy digits were measured and compared. Functional outcomes were evaluated on Takigawa criteria. Pain was measured on a 10-cm visual analog scale. We assessed the affected upper extremity on the Musculoskeletal Tumor Society score questionnaire. RESULTS: Mean bone healing time was 5.5 (4-8) weeks. Pin site infection was observed in 1 patient and cured with dressing changes. Mean follow-up was 34 months, with no recurrences or refractures. Mean active range of motion of the proximal interphalangeal joint, grip and key pinch strength of the involved digits reached 92%, 97%, and 99% of the contralateral digits, respectively. On Takigawa criteria, 20 functional results were excellent and 1 good. Mean pain score was 1 (0-3) cm. Mean Musculoskeletal Tumor Society score was 95 (80-100). CONCLUSION: The combination of bone cement and K-wires is a reliable technique for pathological fracture related to solitary enchondroma close to the joints of the digits, leading to good functional outcomes. LEVEL OF EVIDENCE: Therapeutic study, Level IVa.

Nasal chondrogenic tumors: Case reports of primary chondroma and recurrence of atypical cartilaginous tumor (chondrosarcoma grade I) with review of the literature.

Nasal chondromas and nasal atypical cartilaginous tumors (or chondrosarcoma grade 1) are very rare chondrogenic tumors. Approximately 150 cases of nasal chondroma and fewer than 50 cases of nasal atypical cartilaginous tumors have been described. We reported a case with nasal chondroma in the right ethmoid area and a case with a nasal atypical cartilaginous tumor of the anterior septum. No chondroma recurrence was noted for 17 years after endoscopic resection. Recurrence was noted for the nasal atypical cartilaginous tumor 36 months after wide surgical excision via midfacial degloving. Revision surgery was performed again via midfacial degloving. Recurrences of nasal chondroma and atypical cartilaginous tumors are extremely rare. The current data indicate adequate surgical excision, in some cases even radical, as the most important parameter to avoid recurrence. For inoperable recurrent cases of atypical cartilaginous tumors, observation may be followed.

Mutant IDH regulates glycogen metabolism from early cartilage development to malignant chondrosarcoma formation.

Chondrosarcomas are the most common malignancy of cartilage and are associated with somatic mutations in isocitrate dehydrogenase 1 (IDH1) and IDH2 genes. Somatic IDH mutations are also found in its benign precursor lesion, enchondromas, suggesting that IDH mutations are early events in malignant transformation. Human mutant IDH chondrosarcomas and mutant Idh mice that develop enchondromas investigated in our studies display glycogen deposition exclusively in mutant cells from IDH mutant chondrosarcomas and Idh1 mutant murine growth plates. Pharmacologic blockade of glycogen utilization induces changes in tumor cell behavior, downstream energetic pathways, and tumor burden in vitro and in vivo. Mutant IDH1 interacts with hypoxia-inducible factor 1α (HIF1α) to regulate expression of key enzymes in glycogen metabolism. Here, we show a critical role for glycogen in enchondromas and chondrosarcomas, which is likely mediated through an interaction with mutant IDH1 and HIF1α.

Prevalence and characteristics of benign cartilaginous tumours of the knee joint as identified on MRI scans.

BACKGROUND: Enchondromas (EC) and atypical cartilaginous tumours (ACT) of the knee joint represent benign/intermediate chondromatous neoplasms of the bone that are most commonly discovered incidentally. Based on small to intermediate-sized cohorts, the prevalence of cartilaginous tumours of the knee as visible in MRI is estimated at 0.2-2.9%. This study aimed at verifying/challenging these numbers via retrospective examination of a larger, uniform patient cohort. METHODS: Between 01.01.2007 and 01.03.2020, 44,762 patients had received an MRI of the knee for any indication at a radiologic centre. Of these, 697 patients presented with MRI reports positive for cartilaginous lesions. In a three-step workflow, 46 patients were excluded by a trained co-author, a radiologist and an orthopaedic oncologist, as wrongly being diagnosed for a cartilage tumour. RESULTS: Of 44,762 patients, 651 presented with at least one EC/ACT indicating a prevalence of 1.45% for benign/intermediate cartilaginous tumours of the knee joint (EC: 1.4%; ACTs: 0.05%). As 21 patients showed 2 chondromatous lesions, altogether 672 tumours (650 ECs [96.7%] and 22 ACTs [3.3%]) could be analysed in terms of tumour characteristics: With a mean size of 1.6 ± 1.1 cm, most lesions were located in the distal femur (72.9%), in the metaphysis of the respective bone (58.9%) and centrally in the medullary canal (57.4%). CONCLUSIONS: This study revealed an overall prevalence of 1.45% for cartilage lesions around the knee joint. Whilst a constant increase in prevalence was found for ECs over 13.2 years, prevalence remained constant for ACTs.

Soft Tissue Chondroma of the Chin.

Soft tissue chondromas are benign tumors, generally of the hands or feet, very rarely of the head and neck region. Repeated microtrauma may be as an initiating factor. The authors describe a case of a soft tissue chondroma of the chin in a 58-year-old male who had used a continuous positive airway pressure face mask for obstructive sleep apnea for 3 years. The patient presented with a hard mass on his chin for 1 year. Computed tomography imaging showed a heterogeneous enhancing mass, with calcification in the subcutaneous layer. Intraoperatively, the mass was beneath the mentalis muscle and abutted the mental nerve, without bone involvement. The diagnosis was a soft tissue chondroma. The patient recovered fully, without recurrence. The primary cause of soft tissue chondromas is unknown. The authors consider that continuous use of a continuous positive airway pressure face mask may play a role in the etiology.