Mazabraud's syndrome: case report and literature review

Mazabraud's syndrome: A case report supported by molecular studies and review of the literature

Mazabraud's syndrome represents rare benign disorder characterized by simultaneous occurrence of fibrous dysplasia of bone and intramuscular myxomas within surrounding soft tissue. Mutations of GNAS1 gene were proven to be causative for this condition. Here, we present a case report of a patient with unusual manifestation of this disease, who developed a pathological fracture of the femur in the setting of monostotic fibrous dysplasia. The intramuscular myxoma of the thigh was discovered during the following orthopedic operation, where the intraoperative diagnosis became a pitfall of the case, as the intramuscular myxoma was initially diagnosed as a low-grade sarcoma from the frozen section. Apart from clinical findings, the diagnosis of Mazabraud's syndrome was further proven by histopathological evaluation and molecular studies of GNAS1 gene. This case raises awareness of such condition as it can easily become a diagnostic pitfall.

Extent of Extraskeletal Manifestations of Fibrous Dysplasia/McCune-Albright Syndrome in Patients with Mazabraud's Syndrome

Mazabraud's syndrome (MZB) is a rare condition in which fibrous dysplasia of bone/the McCune-Albright syndrome (FD/MAS) co-exists with intramuscular myxomas. Both FD and the myxomas harbor the GNAS-mutation. Recent studies have shown that extraskeletal, GNAS-related features are associated with a more severe phenotype of FD/MAS. However, patients with MZB are often only seen by orthopedic surgeons. We therefore evaluated MZB patients seen in tertiary referral centers from the Netherlands (LUMC), USA (National Institutes of Health) and France (INSERM UMR 1033 (Lyos), Hôpital Edouard Herriot). All FD/MAS patients known in these centers with an additional diagnosis of a myxoma were included. Demographic information and data on disease extent and extraskeletal manifestations of FD/MAS such as precocious puberty (PP) or café-au-lait patches (CAL) were retrieved from patient's medical records. Thirty MZB patients were included: 20 women (67%) and 10 men (33%). Patients received a diagnosis of MZB (median 42 years, range 16-19) significantly later than the diagnosis of FD/MAS (median 30 years, range 0-60), p < 0.01. Twenty-six patients were diagnosed with polyostotic disease (87%). In 97% the myxoma was located near the skeletal FD lesion. The combination of MZB and MAS was made in 13 patients in whom PP (n = 7), CAL (n = 7), GH-excess (n = 3) and hyperthyroidism (n = 3) were present. Other extraskeletal features were (multinodular) goiter (n = 2) and thyroid cysts (n = 1). Furthermore, in this cohort of patients with MZB several (pre-)malignant tumors were observed; ductal carcinoma in situ of the breast in 3 patients (10%), breast cancer in 1 patient (3.3%), intra pancreatic mucinous neoplasms in 3 patients (10%) and liver adenomas in 2 patients (6.6%). A total of 47% of patients with MZB had an additional extraskeletal feature such as an endocrinopathy. In MZB, 87% of patients suffer from polyostotic FD, 43% of patients have extraskeletal GNAS-features such as an hyperfunctioning endocrinopathy and 30% (pre-)malignant tumors. We therefore advocate that MZB patients should undergo a complete screening and long-term follow-up for extent of bone disease, but also extraskeletal GNAS features of FD/MAS.

A novel approach for fibrous dysplasia assessment using combined planar and quantitative SPECT/CT analysis of Tc-99m-diphosphonate bone scan in correlation with biological bone turnover markers of disease activity

Purpose

To investigate the emerging role of Tc-99m-labeled diphosphonate (Tc-99m-DPD) uptake quantification by SPECT/CT in fibrous dysplasia (FD) bone lesions and its correlation with biological bone turnover markers (BTMs) of disease activity.

Materials and methods

Seven patients (49 ± 16 years) with a confirmed diagnosis of FD were included in this retrospective study. Bone scans with Tc-99m-DPD and quantitative SPECT/CT (xSPECT/CT) were performed. SUV_max (maximum standard unit value) and SUV_mean (mean standard unit value) were measured in all FD bone lesions. The skeletal burden score (SBS) was assessed on planar scintigraphy and multiplied by mean SUV _max and SUV_mean to generate two new parameters, SBS_SUV_max and SBS_SUV_mean, respectively. Planar and xSPECT/CT quantitative measures were correlated with biological BTMs of disease activity, including fibroblast growth factor 23 (FGF-23), alkaline phosphatase (ALP), procollagen 1 intact N-terminal propeptide (P1NP) and C-terminal telopeptide (CTX), as well as scoliosis angle measured on radiographs. Statistical significance was evaluated with Spearman's correlations.

Results

A total of 76 FD bone lesions were analyzed, showing an average SUV_max and SUV_mean (g/mL) of 13 ± 7.3 and 8 ± 4.5, respectively. SBS, SBS_SUV_max and SBS_SUV_mean values were 30.8 ± 25.6, 358 ± 267 and 220.1 ± 164.5, respectively. Mean measured values of FGF-23 (pg/mL), ALP (U/L), P1NP (μg/L) and CTX (pg/mL) were 98.4 (22-175), 283.5 (46-735), 283.1 (31-1,161) and 494 (360-609), respectively. Mean scoliosis angle was 15.7 (7-22) degrees. We found a very strong positive correlation between planar-derived SBS and CTX (r = 0.96, p = 0.010), but no significant correlation between SUV_max or SUV_mean and biological BTMs. SBS_SUV_max showed a strong to very strong positive correlation with CTX (ρ = 0.99, p = 0.002), FGF-23 (ρ = 0.91, p = 0.010), ALP (ρ = 0.82, p = 0.020), and P1NP (ρ = 0.78, p = 0.039), respectively.

Conclusion

This study showed that biological BTMs are significantly correlated with diphosphonate uptake on bone scan, quantified by a new parameter combining information from both planar and quantitative SPECT/CT. Further analysis of bone scan quantitative SPECT/CT data in a larger patient population might help better characterize the skeletal disease burden in FD, and guide treatment and follow-up.

Mazabraud's Syndrome - A Diagnosis Commonly Missed

Introduction:

Mazabraud’s syndrome is a rare benign disorder characterized by the association of single or multiple intramuscular myxomas with monostotic or polyostotic form of fibrous dysplasia. Around 80 cases have been described till date; however, a higher incidence may be expected due to silent nature of the disease and missed diagnosis. The authors report one such case of a missed diagnosis.

Case Report:

A 39-year-old lady presented with recurrent soft tissue myxomas in thigh. A thorough evaluation with radiographs and magnetic resonance imaging (MRI) and a clinical suspicion of this rare entity helped in making the diagnosis of Mazabraud’s syndrome. The patient was treated with wide excision of the recurrent thigh swelling and watchful observation of two other asymptomatic swelling detected on MRI examination. Bisphosphonate therapy was given for fibrous dysplasia. At latest follow-up after 2 years, the patient was asymptomatic with no recurrence.

Conclusion:

The report highlights the importance of a high degree of suspicion of this clinical entity in patients treated for recurrent soft tissue swelling as both myxomas and fibrous dysplasia behave differently than their isolated counterparts.

Osteosarcomatous Transformation in the Setting of Mazabraud's Syndrome: A Case Report and Review of the Literature

Introduction

Mazabraud's Syndrome is a rare condition that is defined by the presence of fibrous dysplasia lesions in the bone and intramuscular myxomas in the soft tissue. Malignant transformation, in the setting of Mazabraud's Syndrome, of the fibrous dysplasia lesions into a sarcomatous neoplasm occurs in less than 1% of cases-with only six previously reported cases.

Case Presentation

Here, we present a 62-year-old Caucasian female who developed an osteosarcoma in a fibrous dysplasia lesion of the proximal femur in the background of Mazabraud's Syndrome. The patient was treated with wide excision and endoprosthetic reconstruction. She declined adjuvant chemotherapy. She is alive without evidence of disease one-year postoperatively.

Conclusion

Patients with Mazabraud's Syndrome remain at low risk for malignant transformation. However, close monitoring of asymptomatic patients with this condition for radiographic changes in their lesions and/or clinical symptoms is recommended.

18F-FDG PET/CT and MRI features of myxoid liposarcomas and intramuscular myxomas

OBJECTIVE

To examine the imaging characteristics of intramuscular myxomas (IM) and myxoid liposarcomas (MLS) on ¹⁸F-FDG PET/CT and MRI.

MATERIALS AND METHODS

With IRB approval, our institutional imaging database was searched for pathologically proven IM and MLS evaluated by ¹⁸F-FDG PET/CT and MRI. PET/CT and MRI imaging characteristics were recorded and correlated with pathologic diagnosis.

RESULTS

We found eight patients (2 M, 6 F) with IM (mean age 65.6 ± 10.4 years) and 16 patients (7 F, 9 M) with MLS (mean age 42.8 ± 16.3 years). MRI was available in 7/8 IM and 15/16 MLS patients. There was no significant difference between the two groups in SUVmax (IM 2.7 ± 0.8, MLS 3.0 ± 1.0; p = 0.35), SUVmean (1.7 ± 0.4, 1.5 ± 0.5; p = 0.40), total lesion glycolysis (101.8 ± 127.3, 2420.2 ± 4003.3 cm³*g/ml; p = 0.12), metabolic tumor volume (62.3 ± 71.1, 1742.9 ± 3308.0 cm³; p = 0.17) or CT attenuation (p = 0.70). MLS occurred in younger patients (p = 0.0015), were larger (16.4 ± 8.2 vs. 5.6 ± 2.5 cm; p = 0.0015), more often T1 hyperintense (p = 0.03), with nodular enhancement (p = 0.006), and macroscopic fat on CT (p = 0.0013) and MRI (p = < 0.001) compared to myxomas.

CONCLUSIONS

IM and MLS most commonly demonstrate low-grade FDG activity and overlapping metabolic measures on PET/CT. MRI is useful in differentiation, but MLS can present without macroscopic fat on MRI, underscoring the importance of radiologic-pathologic correlation for accurate diagnosis.

Fibrous dysplasia for radiologists: beyond ground glass bone matrix

Fibrous dysplasia (FD) is a congenital disorder arising from sporadic mutation of the α-subunit of the Gs stimulatory protein. Osseous changes are characterised by the replacement and distortion of normal bone with poorly organised, structurally unsound, fibrous tissue. The disease process may be localised to a single or multiple bones. In McCune-Albright syndrome (MAS), fibrous dysplasia is associated with hyperfunction of endocrine organs and overproduction of melanin in the skin, while Mazabraud syndrome FD is associated with intramuscular myxomas. In radiology, FD is very often automatically associated with the term "ground glass matrix". However, FD is a complex disease, and knowledge of its unique pathogenesis and course are crucial to understanding imaging findings and potential complications. This article aims to not only summarise the spectrum of radiological findings of osseous and extra-osseous abnormalities associated with FD but also to highlight the pathological base of the disease evolution, corresponding imaging changes and complications based on the disease distribution. We also have provided current recommendations for clinical management and follow-up of patients with FD. TEACHING POINTS: • FD is often a part of complex disease, involving not only bone but also multiple other organs. • FD lesions are characterised by age-related histological, radiographical and clinical transformations. • Radiologists play a crucial role in the identification of osseous complications associated with FD. • The craniofacial form of the disease is the most common type of FD and the most difficult form to manage. • Patients with McCune-Albright syndrome may have different extra-skeletal abnormalities, which often require follow-up.

[Mazabraud and McCune-Albright syndromes in association : A case of two very rare orthopaedic tumour entities]

We report on a 47-year-old woman with unilateral fibrous dysplasia and three intramuscular masses. Medical imaging revealed possible intramuscular myxomas, so that the suspected diagnosis was Mazabraud syndrome. After biopsy, the suspected diagnosis was verified by histology and molecular pathology. Due to endocrine abnormalities in the patient's medical history, McCune-Albright syndrome has was also verified.

Mazabraud's Syndrome Mimicking Metastases on FDG PET/CT in a Patient With Colon Cancer

Mazabraud's, a syndrome consisting of fibrous dysplasia and soft tissue myxomas, is a rare disorder with less than 100 cases reported in the literature. Appearance of lesions in Mazabraud's syndrome on FDG PET/CT scan in an oncological scenario can be misinterpreted as malignancy. We present the case of a 69-year-old woman, diagnosed with metastatic colon carcinoma and suspected osseous as well as soft tissue metastases, who was later found to have concomitant Mazabraud's syndrome. This case describes the diagnostic dilemma associated with this unusual entity and importance of differentiating benign and malignant etiologies on FDG PET/CT scan.

Monosotic fibrous dysplasia and solitary intramuscular myxoma of the head and neck: A unique presentation of Mazabraud's syndrome and a literature review

Mazabraud's syndrome (MS) is a rare disease that is a combination of fibrous dysplasia and intramuscular myxomas. MS is a benign lesion and there is little data on the disease due to its low incidence. In the present study, the case of a 38-year-old patient who presented with a soft-tissue mass involving the masseter and swelling at the mandibular body and mandibular ramus is reported. Since the mandible is an important aesthetic and functional organ in the oral and maxillofacial region, surgery was primarily aimed at resecting the tumor, with good safety margins, and reconstructing the resultant defect. The lesions were pathologically diagnosed as MS. The unique features of this case included the painless and monostotic fibrous dysplasia, the solitary intramuscular myxomas involving the jaw and the male gender of the patient. MS usually occurs in the lower extremities, with an unusual predilection for the right limb; however, it rarely occurs in the head and neck region. A retrospective analysis of the clinical features and management of MS was also performed in the present study, together with a literature review. From the literature, it was concluded that the incidence of MS is ~2.3-fold greater in female patients than in male patients, and that the age of onset of MS ranges between 17 and 82 years, with an average age of 46.25 years.

Mazabraud's syndrome: Report of its first incidence in the Middle East and a literature review

INTRODUCTION

Mazabraud's syndrome, a rare benign disease with indolent course, is best described as an association between soft tissue myxoma and fibrous dysplasia of the bones. In this report, we describe the first case of this syndrome from Saudi Arabia.

CASE PRESENTATION

A 24-year-old male in overall good health status, presented with progressive left knee swelling over 6 years with no other associated symptoms. The swelling measured 5 cm in diameter, with smooth surface, and soft palpable texture. Radiological examination followed by histopathological examination of the excised mass confirmed our diagnosis of Mazabraud's syndrome. The patient was closely followed up with systematic examination with no recurrence.

DISCUSSION

Fibrous dysplasia, soft tissue myxoma and multiple endocrinological diseases like McCune-Albright syndrome characterize Mazabraud's syndrome. Furthermore, fibrous dysplasia is found to be associated with GNA1S gene mutation. Many patients can have asymptomatic course of the disease but may present with pathological fractures, pain, and limitation of movement when the myxoma is near the joints or just simple cosmetically disturbing swelling like in our case.

CONCLUSION

Patients with such presentation need to be investigated thoroughly to rule out associated diseases and to evaluate the extent of such pathology. The improvement of radiological modalities can help in narrowing the differential diagnosis and following the patient to early detect the recurrence or any malignant transformation of the condition.

Polyostotic fibrous dysplasia associated with intramuscular myxomas: Mazabraud syndrome

The authors report a new case of Mazabraud syndrome in a 69-year-old woman complaining of pain in her right thigh. Plain radiographs demonstrated radiological findings consistent with polyostotic fibrous dysplasia of the right femur and tibia. Magnetic resonance imaging (MRI) study showed soft tissue tumors located in the vastus intermedius muscle with typical signal features of intramuscular myxomas. Biopsy was not performed because of its benign nature. Symptomatic treatment was prescribed and all the lesions remained 1 year after the diagnosis.

Mazabraud's syndrome and thyroid cancer, a very rare and confusing association: a case report

BACKGROUND

Mazabraud's syndrome is defined as the association between fibrous dysplasia and intramuscular myxomas. The syndrome was first described in 1967 and, up until now, less than 100 cases have been reported worldwide. Here we report the association between this rare syndrome and thyroid cancer. When a malignant disease occurs in a patient affected by this syndrome, the differential diagnosis between benign and malignant bone lesions should be undertaken carefully.

CASE PRESENTATION

We report the case of a 57-year-old Caucasian male, admitted for diffuse bone pain localized in the left leg and for the presence of an indolent, slow-growing mass in the left shoulder. The patient also presented with a thyroid nodule, highly suggestive of a malignancy. The radiologic examination showed multiple osteolytic lesions. The suspicion of multiple myeloma or bone metastases arising from a thyroid cancer was considered. Electrophoresis of proteins was negative and therefore excluded the diagnosis of multiple myeloma; the thyroid surgery was indicated. Thyroidectomy confirmed the papillary thyroid carcinoma, and the bone lesions were considered to be metastases from the thyroid cancer. After surgery, under thyroid-stimulated hormonal conditions, the patient underwent radioiodine therapy and a post-therapy radioiodine whole body scan. The lack of radioiodine uptake, both in the bone lesions and shoulder mass, suggested the possibility of less differentiated, non-avid radioiodine lesions, or the absence of any relation between pathologies. Considering the low level of the specific tumor marker, thyroglobulin, a bone biopsy and resection of the shoulder mass were indicated. The final diagnosis was intramuscular myxoma with polyostotic fibrous dysplasia in the deltoid muscle (Mazabraud's syndrome). A completely incidental cerebral tumor lesion was also discovered.

CONCLUSION

During the evolution of a malignant disease, Mazabraud's syndrome, known as the association of intramuscular myxoma with fibrous dysplasia, should be considered in the differential diagnosis of bone metastasis. This is the first report in the literature of Mazabraud's syndrome occurring in a patient with thyroid cancer.

Myxoid soft-tissue neoplasms: comprehensive update of the taxonomy and MRI features

OBJECTIVE. The purpose of this article is to review the classification, clinical presentation, and histopathologic and MRI features of myxoid soft-tissue neoplasms. CONCLUSION. MRI is the modality of choice for characterization of myxoid soft-tissue tumors. A combination of imaging features (including certain characteristic signs), clinical features, and patient demographics can help the radiologist in coming to a specific diagnosis or in narrowing down the differential diagnoses.