Fibrous dysplasia imitating malignancy

Craniofacial fibrous dysplasia: A review of current literature

INTRODUCTION

Fibrous dysplasia (FD) is a rare genetic disease, in which normal bone is replaced by fibro-osseus tissue. Disease severity varies greatly from single monostotic lesions to widespread polyostotic disease. Craniofacial lesions are common and, due to the complex anatomy, can cause several disabling symptoms and local extra-skeletal complications. Since relatively rare, reported cases of craniofacial FD (CFD), specifically, are few and the appropriate management remains incompletely defined.

METHODOLOGY

We performed a systematic literature review following the PRISMA guidelines for articles considering CFD in the years 2010-2023. The search was conducted in the PubMed and OVID Medline libraries. Altogether 193 articles were retrieved and reviewed.

RESULTS

Overall, the clinical presentation of CFD is highly variable depending on site and extent of lesion, with pain, deformity or impairment of function being most common. Diagnoses are often incidental and primarily based on CT imaging, while more extensive imaging, genetic studies and lesion biopsies are reserved for unclear cases. Asymptomatic patients are suitable for observation, while symptomatic or widespread disease may require more active approach with medical or surgical treatment. Follow-up is encouraged in all patients to observe possible lesion reactivation, late-stage complications and, though rarely, malignant transformation. Management should be individually tailored with a multidisciplinary team and wholesome consideration of individual needs.

CONCLUSIONS

This review provides an updated discussion on craniofacial FD with focus on improved understanding of disease pathophysiology, appropriate line of surgical management, and new potential means of medical treatment.

Multimodal imaging diagnosis for bone fibrous dysplasia malignant transformation: A case report

Fibrous dysplasia of bone (FDB) is a rare benign condition in which fibrous tissue replaces normal bone architecture. FDB rarely undergoes malignant transformation, but there are reports of locally aggressive fibrous dysplasia with cortical destruction and soft tissue extension. Diagnosis of FDB malignant transformation is not easy, especially in monostotic form, because of the overlap in imaging features of locally aggressive fibrous dysplasia and fibrous dysplasia with malignant transformation. The present case study reports a rare case of FDB in a 23-year-old man with polyostotic fibrous dysplasia arising in the left side of the pelvis and lower limb bones with partial transformation to fibrosarcoma. This study explored the multimodal imaging features of FDB malignant transformation, to achieve early detection and improve diagnostic accuracy of local FDB aggressiveness and its malignant transformation.

Clinical and Molecular Study of ELMO-2-Related Massive Intraosseous Vascular Malformations: Lessons Learned From 25 Years of Follow-up

Massive intraosseous vascular malformations, a relatively rare entity in the vascular malformation spectrum, deserves attention as involving the membranous bones of the craniofacial skeleton and may lead to severe life-threatening hemorrhages and even death. The main aim of this study was to summarize the 25 years of clinical experience with these vascular malformation osseous patients, focus on the molecular and genetic aspect of the clinical entity, and to emphasize the certain challenging conditions in the treatment of these patients. All the patients appeared to be unaffected at birth, whereas initial symptoms occasionally began with painless swelling in the mandible in early childhood. The disease was progressive in behavior especially in the pubertal ages and was specifically involving the maxilla and mandible of the craniofacial skeleton in all the patients. Calvarium and cranial base were the second most common involved regions among these patients (62.5%). Clavicular (50%), costal (25%), and vertebral (25%) involvements were also a significant manifestation of the disease. Tissue samples obtained from the affected individuals and the blood samples from their families were matched, revealing a loss of function mutation in the ELMO-2 gene of chromosome 20 leading to developmental abnormality of the vascular structures via RAC1 signaling and leading to abnormally enlarged vessels in the intraosseus portion of the membranous bone. Immunohistochemical staining revealed positive CD31 and smooth muscle actin staining but negative proliferation and maturity markers such as Ki-67, desmin, h-caldesmon, and myofibroblast-like desmin. The follow-up of 3 of 5 patients ended up with mortality (60%). vascular malformation osseous is intraosseous vascular malformation with aggressive biological behavior associated with ELMO-2 gene mutation. Further studies for obtaining prenatal diagnosis and achievement of gene therapy should take place. As the disease rapidly progresses as the affected individual grows, surgical interventions should be taken into consideration before the initiation of complications.