The Rizzoli Multiple Osteochondromas Classification revised: describing the phenotype to improve clinical practice.

Multiple osteochondromas (MO) is a rare disorder, characterized by benign osteocartilaginous tumors (osteochondromas), arising from the perichondrium of bones. The osteochondromas increase during growth, frequently causing deformities and limitations. Our study aims to analyze the data captured by the Registry of Multiple Osteochondromas, to refine Istituto Ortopedico Rizzoli (IOR) Classification, providing a representative picture of the phenotypic manifestations throughout the lifespan. We conducted a single-institution cross-sectional study. Patients were categorized according to IOR Classification, which identifies three patients' classes on the presence/absence of deformities and/or limitations. The present dataset was compared with our previously published data, to refine the classification. Nine hundred sixty-eight patients were included: 243 children (<10 years), 136 adolescents (10-15 years), and 589 adults. Of the entire population, half patients presented at least one deformity, and one quarter reported at least one limitation. Compared with our previous study, the amount of children was more than doubled and the percentage of mild/moderate cases was notably increased, giving a better disease overview throughout the lifespan and suggesting a different cut-off for dividing Class II in subclasses. We confirmed that MO is characterized by phenotypic heterogeneity, suggesting that an early classification of the disease may offer a useful tool to follow disease pattern and evolution, to support clinical practice, and to propose timely interventions.

Osteochondroma of the mandibular condyle: a classification system based on computed tomographic appearances.

OBJECTIVE: The objectives of this study were to introduce the classification of osteochondroma of the mandibular condyle based on computed tomographic images and to present our treatment experiences. MATERIALS AND METHODS: From January 2002 and December 2012, a total of 61 patients with condylar osteochondroma were treated in our division. Both clinical and radiologic aspects were reviewed. The average follow-up period was 24.3 months with a range of 6 to 120 months. RESULTS: Two types of condylar osteochondroma were presented: type 1 (protruding expansion) in 50 patients (82.0%) and type 2 (globular expansion) in 11 patients (18.0%). Type 1 condylar osteochondroma presented 5 forms: anterior/anteromedial (58%), posterior/posteromedial (6%), medial (16%), lateral (6%), and gigantic (14%). Local resection was performed on patients with type 1 condylar osteochondroma. Subtotal condylectomy/total condylectomy using costochondral graft reconstruction with/without orthognathic surgeries was performed on patients with type 2 condylar osteochondroma. During the follow-up period, tumor reformation, condyle absorption, and new deformity were not detected. The patients almost reattained facial symmetry. CONCLUSIONS: Preoperative classification based on computed tomographic images will help surgeons to choose the suitable surgical procedure to treat the condylar osteochondroma.

[Cartilage tumors of the skeleton]. / Chondrogene Tumoren des Skeletts.

Although the spectrum of benign and malignant cartilaginous bone tumors is extremely wide, a distinct diagnosis, even from small biopsy specimens, is almost always possible if radiological findings, age, clinical data, and localization within the skeleton as well as within the bone are considered. With limitations, this also holds true for distinguishing enchondromas from low-grade chondrosarcomas; however, extensive experience in multidisciplinary bone tumor diagnosis is required. In single cases, immunohistochemical findings may be helpful in the differential diagnosis if they are integrated into the context of all other findings. Because of treatment-related or prognosis-related consequences, collaboration with a reference center is recommended.

Dedifferentiated chondrosarcoma of the appendicular skeleton: MRI-pathological correlation.

OBJECTIVE: To correlate the T2-weighted and STIR MRI appearances of dedifferentiated appendicular chondrosarcoma with gross and microscopic pathology. DESIGN AND PATIENTS: Nine patients with a histologically confirmed diagnosis of dedifferentiated appendicular chondrosarcoma were identified from the Bone Tumour Registry. All patients underwent MRI, including T2-weighted and/or STIR sequences in at least one plane, prior to limb salvage surgery. Areas of reduced signal intensity (SI) compared with hyperintense chondral tumour on the T2-weighted or STIR images were correlated with the resection specimen, to determine the relationship of such out areas of reduced SI with regions of dedifferentiation. RESULTS AND CONCLUSIONS: Patients presented over a period of 7 years. There were five men and four women with mean age 68.2 years and age range 51-78 years. Tumours arose in the femur (6 cases), humerus (2 cases) and tibia (1 case). Three MRI patterns were identified: (1) type 1, a lesion with two distinct signal characteristics-hyperintense chondral and reduced SI dedifferentiated tumour (n=6); type 2, mainly reduced SI lesion-dedifferentiated tumour, with areas of signal void corresponding to matrix calcification (n=2); type 3, a heterogeneous lesion with no radiological evidence of underlying chondral tumour (n=1). T2-weighted or STIR MR sequences can identify areas of dedifferentiation, which should be the preferential site of pre-operative biopsy.