Chondroblastomas in Children and Young Adults: Revision of 55 Cases.

BACKGROUND: Chondroblastomas are uncommon primary bone tumors localized in long bone epiphyses in children and young adults. The risk of metastasis is rare, but they have a high capacity for local recurrence. Surgical curettage with bone grafting or bone substitute is the preferred treatment. METHODS: We performed an observational retrospective study of chondroblastomas treated in 2 hospitals in Barcelona from 1988 to 2018. We reviewed the location of the tumor, clinical presentation, imaging, histopathology, initial treatment, and cases of recurrence with a review of their treatment. We assessed the correlation between recurrence and index surgery, anatomic location, and certain histopathologic findings (presence of mitotic figures, necrosis, and positivity for protein S-100). RESULTS: The series included 55 patients treated from 1988 to 2018, with ages ranging from 6 to 26, and a mean follow-up of 6.1 years (±3.7). The most common location was the distal femur metaphyseal/epiphyseal region. The most frequent clinical presentation was pain in the affected. Forty-five cases (81.8%) were treated with curettage of the tumor, and 4 cases (7.3%) with a wide resection. Forty-two cases (85.7%) received bone substitutes after curettage or resection. We found 5 cases of recurrence (9.1% recurrence rate); however, we could not find a statistically significant correlation between index surgery and recurrence ( P =0.24), anatomic location and recurrence ( P =0.49), or recurrence and histopathologic findings (mitotic figures, P =0.49; necrosis, P =0.60; positivity for protein S-100, P =0.52). In all the cases the treatment for the local recurrence was surgical, with a final healing rate of 100%. CONCLUSIONS: Chondroblastomas should be considered in children and adolescents when presenting with pain and an image suggestive of a tumoral lesion on plain x-ray, most frequently in epiphyses of long bones.Surgical treatment is preferred, obtaining good results after curettage and bone substitute. Chondroblastomas are tumors with a high capacity for recurrence, therefore an adequate surgical technique and surgeon experience are paramount to achieve good outcomes. LEVEL OF EVIDENCE: Level IV (case series). Therapeutic studies-investigating results or treatment.

Pharmacogenetic Profiling in High-Risk Soft Tissue Sarcomas Treated with Neoadjuvant Chemotherapy.

Neoadjuvant chemotherapy based on anthracyclines and ifosfamide for high-risk soft tissue sarcomas (STS) of the extremities and trunk is a controversial treatment option. There are substantial interindividual differences in clinical outcomes in patients treated with neoadjuvant chemotherapy. The aim of this study was to evaluate, as biomarkers, polymorphisms in genes encoding drug-metabolizing enzymes, drug transporters, or drug targets and their association with toxicity and survival in STS patients treated with neoadjuvant chemotherapy. We analysed variants in genes involved in anthracycline metabolism (ABCB1, ABCC2, NQO1, CBR3, and SLC22A16) and in ifosfamide catabolism (ALDH1A1) in 79 treated patients. Two genes showed significant association after adjusted multivariate analysis: ABCC2 and ALDH1A1. In patients treated with anthracyclines, ABCC2 rs3740066 was associated with risk of febrile neutropenia (p = 0.031), and with decreased overall survival (OS) (p = 0.024). ABCC2 rs2273697 was associated with recurrence-free survival (RFS) (p = 0.024). In patients treated with ifosfamide, ALDH1A1 rs3764435 was associated with RFS (p = 0.046). Our pharmacogenetic study shows for the first time that variants in genes regulating the metabolism of neoadjuvant chemotherapy may be helpful to predict toxicity and survival benefit in high-risk STS treated with neoadjuvant chemotherapy. Further validation studies are needed to establish their clinical utility.

Distal radioulnar joint prosthesis for the treatment of giant cell tumor of the distal ulna: a case report and literature review.

Giant cell tumor (GCT) of the distal end of the ulna is an uncommon site for primary bone tumors. When it occurs, en-bloc resection of the distal part of the ulna with or without reconstruction stabilization of the ulnar stump is the recommended treatment. We present a case of a 56-year-old man with a GCT of the distal ulna treated successfully with an en-bloc resection of the distal ulna with reconstruction using radioulnar joint prosthesis. Although the experience with this type of treatment is limited, implantation of a metallic prosthesis to replace the distal part of the ulna can also be considered as a salvage procedure for the treatment of this difficult pathology.