Acute myeloid leukaemia presenting as proptosis in an infant

Paediatric patients with acute myeloid leukaemia (AML) often present with symptoms associated with the disruption of normal haematopoiesis and subsequent cellular deficiencies. Periosteal reactions are common in paediatric leukaemia, but typically manifest as a thin, laminated pattern along long bones. Aggressive periosteal reactions are much less frequently seen. Here, we report a case of paediatric AML initially presenting with proptosis and periorbital swelling caused by aggressive, sunburst periosteal reactions surrounding the sphenoid and zygomatic bones. This unique presentation emphasises the importance of considering leukaemic infiltration in the differential for sunburst periosteal reaction in paediatric patients.

Autologous adipose-derived mesenchymal stem cells and hydroxyapatite for bone defect in rabbits

This study aims to evaluate the effect of autologous adipose-derived mesenchymal stem cells (AAD-MSC), with and without synthetic absorbable hydroxyapatite (HAP-91), on the bone regeneration in rabbits. Thirty-four female white New Zealand rabbits were submitted to a 10 mm distal diaphyseal radius ostectomy, divided into 3 experimental groups according to the treatment established. The bone gap was filled with 0.15 ml of a 0.9% saline solution containing two million AAD-MSC (G1), or AAD-MSC associated with HAP-91 (G2). The control group (CG) received only 0.15 ml of the 0.9% saline solution. Radiographs were made post-operatively, and after 15, 30, 45 and 90 days. Fifty percent of the samples were submitted to a histological examination at 45 days and the remaining ones at 90 days post-operatively. Radiographically, the periosteal reaction, bone callus volume and bone bridge quality were superior in G2 (P < 0.05). Histologically, the bone repair was faster and more efficient in G1 at 45 days (P < 0.05). In conclusion, AAD-MSC improved the regeneration on the experimentally induced bone defects in rabbits; however, the use of hydroxyapatite requires caution given the granulomatous reaction produced in the species.

Atypical Femoral Fracture in a Patient without Bisphosphonate or Denosumab Exposure-A Case Report

Introduction: Atypical femoral fractures (AFF) are associated with the use of bisphosphonates (BPs) or denosumab. However, few cases that meet the characteristics of these fractures, as established by the American Society of Bone and Mineral Research, have occurred in patients who have never used antiresorptive drugs. Case Report:We report a case of AFF in a 67-year-old woman who had never used antiresorptive medications. The history and comorbidities of the patient, the characteristics of the fracture, and the subsequent treatment are presented. Conclusion: AFFs may occur even in patients who have never been exposed to BPs or denosumab. The absence of antiresorptive osteoporosis therapy and the lack of radiographic focal periosteal reaction in the lateral femoral cortex, as in our case, can make it difficult to detect and prevent the disorder. Prolonged use of proton pump inhibitors and Vitamin D deficiency-related osteomalacia may contribute to the occurrence of these fractures. Further studies are required to accurately understand all inciting factors contributing to the development of AFFs. Keywords: Atypical femoral fractures, subtrochanteric fractures, denosumab, bisphosphonates, antiresorptive drugs.

Cone Beam Computed Tomography (CBCT) is Superior to Orthopantomogram (OPG) in Interpreting the Imaging Characteristics of Medication-Related Osteonecrosis of the Jaw (MRONJ and More Stage-Sensitive: A Prospective Assessment in 98 Cancer Patients

Objectives: To prospectively evaluate the imaging characteristics of Medication-Related Osteonecrosis of the Jaw (MRONJ), observed in the Orthopantomogram (OPG) and in Cone Beam Computed Tomography (CBCT), in patients with cancer. Materials and Methods: Cancer patients, who received Bone Targeting Agents (BTAs) and developed MRONJ, were prospectively included in the study. MRONJ was staged following the American Association of Oral and Maxillofacial Surgery (AAOMS) 2014 criteria. Four predefined radiological findings, osteolytic changes, sclerosis, periosteal reaction, and sequestration were assessed and were scored as “absent”, “localized”, “extensive” and “beyond the alveolar bone”. Results: Ninety-eight cancer patients were enrolled. Eighty patients (81.6%) received BTAs for over a year; 19 (19.4%) received BTAs between 13 to 24 months and 61 patients (62.2%) received BTAs for over 24 months. The majority of the patients (n=58, 59.2%) had stage 2 MRONJ and 35 (35.7%) were at MRONJ stage 3.Fifty-two (53.06%) patients were assessed with OPG and 89 (90.81%) with CBCT and CBCT was found more effective in detecting sclerosis and sequestration than OPG.Forty-three (43.87%) patients were assessed with both OPG and CBCT and were available for comparisons between OPG and CBCT. CBCT was significantly more accurate than OPG in interpreting the “beyond the alveolar bone” osteolytic changes, sclerosis, periosteal reaction and sequestration, in all MRONJ stages. P-value was 0.0002, <0.0001, 0.0027 and 0.0009 respectively.Furthermore, CBCT was significantly more accurate than OPG in interpreting the “extensive” and “beyond the alveolar bone” imaging characteristics, when comparisons included the patients with early stages of MRONJ, 1 and 2 and the patients with stage 3 of MRONJ. Conclusion: CBCT is superior and more stage-sensitive to OPG in interpreting and staging MRONJ and can be particularly useful to achieve an early diagnosis of MRONJ.

Central Odontogenic Myxoma: A Radiographic Analysis

Objective. This study aimed to determine the radiographic characteristics of odontogenic myxomas (OMs) and their associations. Materials and Methods. The study enrolled radiographs of patients taken between 2005 and 2019 with a confirmed histopathological diagnosis of central OM. OM radiographic features were evaluated, including location, border, locularity, involved area, the number of included teeth, root resorption, tooth displacement, bone expansion, bone perforation, and periosteal reaction. Fisher’s exact test was used for statistical analysis. Results. Significant associations were found between the OM border and the affected jaw ( p = 0.036 ), locularity ( p = 0.036 ), involved areas ( p = 0.009 ), and bone perforation ( p = 0.036 ). OMs with an ill-defined border were associated with maxillary lesions, multilocularity, dentate areas, and cortical bone perforation. The number of included teeth (2 or fewer or 3 or more) was significantly associated with locularity ( p = 0.010 ), involved area ( p = 0.045 ), and bone expansion ( p = 0.010 ). Larger OMs including 3 or more teeth, were associated with a multilocular appearance, dentate areas, and bone expansion. Conclusion. The border of OM and the number of included teeth are related to other radiographic appearances. Understanding these relationships could help in treatment decisions and help better understand the nature of OM.

Rare Subtype of Medication-Related Osteonecrosis of the Jaw: Imaging Findings and Treatment Outcomes of Periosteal Reaction Dominant Type

PurposeIn our previous study,we found a rare type of medication-related osteonecrosis of the jaw (MRONJ), which shows periosteal reaction (PR) at a site distant from the osteolytic lesions or extraction site (periosteal reaction dominant type: PRd type), even though the osteolytic lesions in the bone marrow are localized. Given that the causes and treatment of MRONJ remain unclear, this study aimed to describe the imaging and clinical features of the PRd type.MethodsPatients with MRONJ who visited Nagasaki University Hospital during 2009-2020 and received conservative therapy as the initial treatment were included in this study. Site of PR, imaging findings, initial symptoms, outcome, and time to progression were examined.ResultsOf the 59 MRONJ patients treated with conservative therapy, 38 did not show PR (PR- type), 15 showed PR near the osteolytic region (PR+ type), and six had the PRd type. All patients with the PRd type had submental abscesses, and computed tomography (CT) images demonstrated PR on the lingual side of the anterior mandible. Osteolytic lesions progressed in 6/6 PRd type (100%), 5/15 PR+ type (33.3%), and 2/38 PR- type (5.3%) patients. Time to progression for the osteolytic region on CT was short for the PRd type, at 56-148 days (median, 79 days).ConclusionAmong the MRONJ types, the PRd type has a poor prognosis. Therefore, it is necessary to accumulate and analyze more PRd cases in the future. This is the first report to report the presence of this specific subtype of MRONJ,

Radiologic findings that aid in the reduction of misdiagnoses of Langerhans cell histiocytosis of the bone: a retrospective study

Background This study aimed to identify the characteristic radiological signs for the diagnosis of Langerhans cell histiocytosis (LCH) of the bone. Methods We retrospectively studied 82 cases of LCH with bone lesions confirmed by pathology. Clinical and radiological features of the patients were analyzed. Results A total of 64 and 18 patients had single and multiple bone lesions, respectively. With regard to LCH with single bone lesions, 37.5% (24/64) of lesions were located in the skull and presented as bone destruction with or without soft tissue mass. The correct diagnosis rate of these lesions was 60.0% (9/15) in children and adolescents, but was only 22.2% (2/9) in adults. A total of 26.5% (17/64) of the solitary lesions were found in the spine. Of these, 88.2% (15/17) were located in the vertebral body and appeared to have different degrees of collapse, and 66.7% (10/15) of these lesions were correctly diagnosed. Of the unifocal lesions, 21.8% (14/64) were located in other flat and irregular bones and manifested as osteolysis. Only 21.4% (3/14) of these cases were correctly diagnosed. In total, 14.1% (9/64) of the isolated bone LCH lesions were located in the long bones. Of these, 77.8% (7/9) were located in the diaphysis and presented as central bone destruction with or without fusiform periosteal reaction and extensive peripheral edema, of which 42.9% (3/7) were correctly diagnosed before surgery or biopsy. With regard to LCH with multiple bony destructive lesions, 71.4% (10/14) of cases in children and adolescents were correctly diagnosed; however, all four cases among adults were misdiagnosed. Conclusion In all age groups, isolated diaphyseal destruction of the long bone with fusiform periosteal reaction and extensive peripheral edema, vertebra plana of the spine, and bevelled edge of skull defects accompanied by soft tissue masses strongly suggest LCH diagnosis. Moreover, the multiple bone osteolytic destruction in children and adolescents strongly suggests LCH diagnosis. Familiarity with these typical radiological signs of LCH is necessary to decrease misdiagnoses.