Medical Imaging Analysis Report

I. Imaging Findings

1. Skeletal findings: Abnormal bone density and “ground-glass appearance” can be observed in multiple sites, with notable local expansile changes of the bone, thinning of the cortex. Some lesions show intracortical medullary expansion with relatively smooth margins, suggesting the typical radiological characteristics of polyostotic fibrous dysplasia.
2. A soft tissue mass is visible on the lateral side of the distal right upper arm. On MRI, it exhibits a markedly high T2 signal and an isointense or slightly low T1 signal with partial clear demarcation from adjacent muscle tissue but no complete capsule. Post-contrast images show irregular enhancement at the tumor’s border and some internal regions, and a hyperintense band connecting with the muscle space, consistent with the imaging features of a myxoma.
3. The bony lesions are widely distributed: the skull, ribs, ilium, and long bones of the extremities all show varying degrees of bone changes, fitting the presentation of multiple lesions affecting multiple bones.
4. The soft tissue lesion is adjacent to severely involved bone areas, which aligns with the typical localization features of fibrous dysplasia combined with intramuscular myxoma.

II. Potential Diagnoses

1. Polyostotic Fibrous Dysplasia
   – Common features: “ground-glass” density changes, cortical expansion, and clear internal margins.
   – Multiple lesions often present in childhood and gradually become more prominent.
   – The patient has a known history of multi-bone involvement, and both the clinical and imaging characteristics are consistent with this diagnosis.
2. Intramuscular Myxoma
   – Typical imaging characteristics: iso- or low-intensity on T1, high signal on T2, and heterogeneous enhancement post-contrast.
   – Usually presents as a localized lesion with smooth borders but no true capsule, often accompanied by a rim of fat within surrounding atrophic muscle.
   – In this case, MRI demonstrates a pronounced myxoid soft tissue lesion.
3. Mazabraud’s Syndrome
   – Characteristic presentation: fibrous dysplasia (often polyostotic) combined with intramuscular myxoma.
   – Reported only in a small number of cases, featuring the combination of these two pathologic entities.
   – Given the patient’s previously diagnosed polyostotic fibrous dysplasia and the appearance of a typical intramuscular myxoma on imaging, this strongly suggests Mazabraud’s syndrome.
4. Other Diagnoses to Exclude
   – Osteosarcoma or other malignancies: Rapid expansion, significant bone destruction, and large-scale soft tissue invasion would raise suspicion for malignant transformation; however, there is currently no clear evidence of malignancy in this case.
   – Other soft tissue tumors (e.g., lipoma, schwannoma): The MRI findings differ from those of a myxoma, and in this case, the findings more strongly support a myxoma.

III. Final Diagnosis

Taking into account the patient’s known history of polyostotic fibrous dysplasia, the appearance of an intramuscular mass in adulthood, and characteristic X-ray and MRI findings, the most likely diagnosis is:

Mazabraud’s Syndrome (polyostotic fibrous dysplasia with intramuscular myxoma).

For further confirmation, histopathological examination or regular follow-up imaging may be performed to rule out malignant transformation and confirm the nature of the soft tissue mass.

IV. Treatment Plan and Rehabilitation Program

1. Treatment Strategy
   • Close Follow-up: If the lesions remain stable and symptoms are mild, periodic follow-up and imaging surveillance may be chosen.
   • Surgical Intervention: In the presence of significant symptoms, functional limitations, or suspicion of malignant transformation, surgical approaches such as lesion excision, curettage, or bone grafting (if there is a high fracture risk or pronounced deformity) should be considered. For large myxomas or those affecting muscle function, surgical resection of the myxoma may also be considered.
   • Medication: Some patients with fibrous dysplasia may benefit from bisphosphonates in collaboration with endocrinology and orthopedics to slow bone destruction or relieve pain. However, currently, no specific medication provides complete control of this disease.
   • Alert for Malignant Transformation: Compared to solitary fibrous dysplasia, Mazabraud’s syndrome carries a higher risk. If there is rapid lesion growth, worsening pain, or newly found lesions, prompt imaging and pathological assessment are recommended.
2. Rehabilitation and Exercise Prescription

   The overall goal is to maintain and improve muscle strength, ensure stable joint range of motion, and prevent fractures or re-injury. Because bone strength is relatively compromised, exercise selection and intensity should be progressive with a focus on safety.

   • Initial Phase
     • Frequency: 2–3 sessions per week, resting 1–2 days between sessions.
     • Intensity: Light to moderate (e.g., 10–15 minutes of low-impact aerobic exercises such as using an elliptical machine or stationary bike, avoiding high-impact running or jumping).
     • Duration: Approximately 20–30 minutes per session.
     • Mode: Range-of-motion exercises and low-load strength training (using resistance bands or light dumbbells).
   • Progressive Phase
     • Frequency: Gradually increase to 3–4 sessions per week.
     • Intensity: Primarily moderate intensity, including core stability and balance training (e.g., seated or standing core exercises, single-leg balance).
     • Duration: 30–45 minutes per session.
     • Mode: Continue flexibility work (stretching and joint mobility) and safely increase weight-bearing exercises to improve strength (avoid excessive range of motion or high-impact activities).
   • Precautions
     • Avoid or minimize high-impact or twisting activities (e.g., running, jumping, forceful rotational maneuvers) to prevent fractures or soft tissue injuries.
     • Monitor any increase in pain or functional limitations during exercise. If these worsen significantly, stop and seek medical evaluation.
     • Under the guidance of rehabilitation or specialist physicians, adjust the training plan regularly.

Disclaimer:
This report is based on the current imaging and medical history for reference purposes only and cannot replace in-person consultations or professional medical diagnoses and treatment. If you have any concerns or if your condition changes, please consult a qualified healthcare provider or physician promptly.