Young Adult With Osteosarcoma of the Mandible and the Challenge in Management: Review of the Pediatric and Adult Literatures Christopher Kuo, MD* and Paul M. Kent, MD, FAAP† Summary: Neoadjuvant chemotherapy for osteosarcoma of the jaw (OSJ) remains controversial despite being a standardized treatment in osteosarcoma of the long bones. We present a case of a 22-year- old male with OSJ and performed a retrospective systemic review of previously published literatures of OSJ. We identified 27 articles: 7% recommended neoadjuvant chemotherapy, 22% recommended adjuvant chemotherapy, 19% recommended both neoadjuvant and adjuvant chemotherapy, 33% recommended against chemotherapy and 19% stated the role of chemotherapy is unknown. The lack of consensus regarding the use of chemotherapy in OSJ, despite its benefits, demonstrates the need to establish a standardized algo- rithm for OSJ. Key Words: osteosarcoma, mandible, osteosarcoma of the jaw, neoadjuvant chemotherapy, young adult (J Pediatr Hematol Oncol 2019;41:21–27) O steosarcoma (OST) most commonly affects the meta- physeal growth plates in the long bones. OST of the jaw (OSJ) is rare, comprising of only 6% to 7% of all OST, or about 55 to 60 cases per year in the US. 1–3 The most common presenting symptoms are swelling pain and numbness of the lower lip. 4 Dentists are the first to evaluate the lesion in 45% of cases, 2/3 are treated initially with tooth extraction and half with antibiotics. 4 OSJ occurs most commonly in the third or fourth decade, 5 and like all OST, surgical resection is the main treatment modality. The demographic and histologic hetero- geneity as well as the rarity of OSJ render it difficult to establish recommendations and standards of care, particularly to study the benefits of chemotherapy. Although the utility of neoadjuvant chemotherapy in OST of the long bones has been well-established since the 1980s, 6,7 it remains controversial in OSJ, which prompted our literature review. The controversy stems from the dif- ferences between adult protocols and their pediatrics coun- terparts, the fraction of OSJ that are low grade, as well as the different paradigms employed most commonly by head and neck oncology surgeons and orthopedic oncology sur- geons. Despite excellent collaborative work across many groups and countries in the European American Osteo- sarcoma Study Group (EURAMOS-1 or COG AOST0331) study for evidenced based therapy recommendations for OST, OSJ was excluded in the protocol, contributing to the lack of general consensus in treatment guidelines for OSJ. Additionally, therapeutic conundrum increases when a young adult (YA) (defined age, 18 to 39) is diagnosed with OSJ, as their age typically directs them to an adult protocol. However, classic OST is a disease predominantly of ado- lescents and young adults with well-established protocols such as AOST0331, whereas OSJ affects all ages thus contributing to the variability. The aim of this study is to report and discuss a case of OST in the mandible of a 22-year-old male, along with the treatment and manage- ment dilemmas of OSJ through literature review. CASE REPORT A 22-year-old male with no significant past medical history presented with an enlarging mass in the mandible originally sus- pected as a dental abscess, treated with cefdinir for a week. After failure of antibiotic treatments, he was referred by a periodontist for evaluation of suspected tumor of the mandible (Fig. 1). Imaging showed a lytic tumor. He was referred to an Otorhinolaryngologist (ENT) who consulted pediatric oncology. Computed tomography (CT) showed a 1.0×3.2×2.9 cm 3 exo- phytic lesion arising from the anterior alveolar cortex of the man- dible in the symphyseal region with multifocal chondroid calcifi- cations (Fig. 2). Biopsy showed chondroblastic osteosarcoma, > 20% high-grade. Initial workup with bone scan, CT chest were negative for metastasis. Baseline labs were drawn: Comprehensive FIGURE 1. Osteosarcoma of the mandible. Received for publication May 14, 2018; accepted August 16, 2018. From the *Department of Pediatrics, Children’s Hospital Los Angeles, Los Angeles, CA; and †Department of Pediatric Hematology/ Oncology, Department of Pediatrics, Rush University Medical Center, Chicago, IL. Informed consent has been properly documented. The authors declare no conflict of interest. Reprints: Paul M. Kent, MD, FAAP, Department of Pediatrics, Medical Director, Sarcoma Program, Rush University Medical Center, Department of Pediatrics, Division of Hematology and Oncology, 1725 West Harrison Street, Suite 710, Chicago, IL 60612-3824 (e-mail: Paul_Kent@Rush.edu). Copyright © 2018 Wolters Kluwer Health, Inc. All rights reserved. ORIGINAL ARTICLE J Pediatr Hematol Oncol  Volume 41, Number 1, January 2019 www.jpho-online.com | 21 Copyright r 2018 Wolters Kluwer Health, Inc. All rights reserved.