Mazabraud's syndrome in female patients: Two case reports

Abstract

Background: Mazabraud's syndrome (MS) is a rare and slowly progressive benign disease characterized by the concurrent presence of fibrous dysplasia of bone and intramuscular myxoma, and is thought to be associated with mutations of the GNAS gene. To date, only about 100 cases of MS have been reported in the literature, but its standard treatment strategy remains unclear.

Case summary: We report two cases of MS in young women who underwent different treatments based on their symptoms and disease manifestations. The first patient, aged 37, received internal fixation and intravenous bisphosphonate for a pathological fracture of the right femoral neck, excision of a right vastus medialis myxoma was subsequently performed for pain control, and asymptomatic psoas myxomas were monitored without surgery. Genetic testing confirmed a GNAS gene mutation in this patient. The second patient, aged 24, underwent right vastus intermedius muscle myxoma resection, and conservative treatment for fibrous dysplasia of the ilium. These patients were followed-up for 17 months and 3 years, respectively, and are now in a stable condition.

Conclusion: Various treatments have been selected for MS patients who suffer different symptoms. The main treatment for myxomas is surgical resection, while fibrous dysplasia is selectively treated if the patient experiences pathological fracture or severe pain. However, given the documented instances of malignant transformation of fibrous dysplasia in individuals with MS, close follow-up is necessary.

Keywords: Bisphosphonate; Case report; Fibrous dysplasia; Intramuscular myxoma; Mazabraud's syndrome.

Figure 1

Representative images. A-I: Representative X-ray (A and B), computed tomography images (C-F), and magnetic resonance (MR) images (G-I) showing bone lesions (orange arrows) in the pelvis, femur, tibia and ribs; J-M: Hematoxylin-eosin (HE) staining results of preoperative puncture biopsy sample from the femoral lesion (J). Representative MR images of intramuscular lesions (orange arrows) in the right psoas major muscle (K) and the right vastus medialis muscle (L), and HE staining result of a puncture biopsy specimen from the myxoma in the psoas major muscle (M).

Figure 2

Representative images. A-C: Representative T1WI (A) and T2WI (B) of MR images, and hematoxylin-eosin staining (C) of the intramuscular lesion (orange arrows) in vastus intermedius muscle; D-F: Representative X-ray (D), T2WI (E) and T1WI images (F) showing bone lesions (orange arrows) in the pelvis and femur.

Figure 3

Representative images. A and B: X-ray image (A) of the right femur after internal fixation, and representative hematoxylin-eosin (HE) staining (B) of postoperative specimen from the femoral fibrous dysplasia; C and D: Representative magnetic resonance (MR) image (C) and HE staining (D) of the intramuscular myxoma in right vastus medialis; E-I: Results of 1-year follow-up of femur X-ray, iliopsoas myxoma and iliac crest fibrous dysplasia. Representative images of femur (E) and tibia (F) X-ray, positron emission tomography-CT (G), iliopsoas myxoma MR (H), and iliac fibrous dysplasia MR (I) at 1-year follow-up.

Figure 4

Schematic diagram of the summary on these two cases of Mazabraud’s syndrome.

Figure 5

Schematic diagram of the differential diagnoses for Mazabraud’s syndrome. FD: Fibrous dysplasia; IM: Intramuscular myxoma; MAS: McCune-Albright syndrome; MS: Mazabraud’s syndrome.