Imaging Findings

The patient’s right shoulder X-ray shows soft tissue swelling in the scapular region, with locally increased density. The bony contours remain generally intact, and there is no obvious sign of fracture. Plain and contrast-enhanced CT scans reveal a relatively large mass in the deep soft tissue of the right scapular region, with a well-defined boundary and increased vascular distribution in the area. After contrast enhancement, the lesion shows marked enhancement, and some areas exhibit low-density necrosis/cystic changes. Abundant vascular shadows can be seen within and surrounding the lesion. MRI indicates that, on T1-weighted images, the mass appears similar to or slightly higher than the muscle signal, while on T2-weighted images, the signal is increased. In some regions, a “target sign” may be observed (lower signal at the periphery and higher signal in the center). After enhancement, prominent peripheral enhancement and internal septations are visible. The tumor extends into the surrounding soft tissue and is adjacent to the scapula, though no clear evidence of bone destruction has been found.

Potential Diagnoses

• Soft tissue sarcoma with possible pulmonary metastasis (particularly suspicious nodules in the hilar or lung fields): Given the patient’s relatively young age, an insidious clinical course, significant local mass enlargement, and imaging showing rich blood supply, a high-blood-supply soft tissue sarcoma should be strongly considered. Possible subtypes include:
  • First consideration: “Pulmonary metastatic” soft tissue sarcoma with pronounced lung metastatic tendencies, such as suspicious satellite lesions in the lung
  • Other potentially suspected soft tissue sarcomas (e.g., synovial sarcoma, leiomyosarcoma, etc.)
• Malignant fibrous histiocytoma (MFH): Certain fibrosarcomas or undifferentiated pleomorphic sarcomas can present as a mass with intratumoral necrosis and striking enhancement on imaging, but this may differ from the rich vascularity noted in this case.
• Inflammatory or infectious lesion: In very rare circumstances, a cystic-solid lesion may show pronounced enhancement and thickened walls in acute inflammatory conditions; however, such cases typically involve acute redness, swelling, heat, and pain. Given the chronic onset and hypervascularity here, the likelihood is low.

Final Diagnosis

Considering the patient’s young age, subtly presenting clinical symptoms, imaging findings of a large soft tissue mass with abundant vascular features, and pathological indicators, the most likely diagnosis is an extra-pulmonary primary soft tissue sarcoma with suspected lung metastases—“a soft tissue sarcoma subtype markedly prone to pulmonary spread,” indicated by suspicious hilar or lung field lesions.

Based on the histological characteristics and clinical course, the final confirmed diagnosis is an alveolar soft part sarcoma (ASPS) with possible lung metastases (“pulmonary metastatic” sarcoma subtype).

Treatment Plan and Rehabilitation

Overview of Treatment Strategy:

• Surgical Treatment: For localized disease, early complete surgical excision is recommended to reduce local recurrence and further metastatic risk. In cases where the tumor invades vital neurovascular structures, a wide resection should be performed with emphasis on preserving limb function and quality of life.
• Radiotherapy: For challenging local control or positive surgical margins, adjuvant radiotherapy may be considered to shrink any remaining tumor and reduce the risk of local recurrence after surgery.
• Chemotherapy: Alveolar soft part sarcoma generally shows limited response to conventional chemotherapy regimens. In cases of widespread metastasis or recurrence, discussion with a multidisciplinary team regarding novel molecular targeted therapies or clinical trials may be warranted.

Rehabilitation and Exercise Prescription (FITT-VP Principle):

1. Strength and Range of Motion Recovery Phase:
   • In the early postoperative or post-radiotherapy period, the main goal is to maintain joint mobility and prevent adhesions. Low-intensity passive or assisted active shoulder movements can be performed once or twice daily, each session lasting 10–15 minutes.
   • If significant pain or edema is noted, apply physical modalities (e.g., cold compresses, ultrasound therapy) and intermittent supervised exercises under clinical guidance.
2. Enhancement and Functional Training Phase:
   • Frequency: 3–4 times per week.
   • Intensity: Gradually increase using resistance bands or light weights (1–2 kg) for rehabilitation of the shoulder girdle muscles.
   • Time: 15–30 minutes per session, extended progressively as tolerance improves.
   • Type: Exercises can include isotonic or isometric training for abduction, flexion, and internal/external rotation of the affected shoulder, progressively incorporating scapular stability exercises.
   • Progression: As muscle strength improves, cautiously add sets or weights in a stepwise manner.
3. Maintenance and Comprehensive Training Phase:
   • After restoration of near-normal upper limb range of motion and muscle strength, more comprehensive exercises (e.g., modified push-ups, kettlebell training, or rowing machine workouts) can be introduced, avoiding excessive impact stress.
   • Emphasize overall cardiopulmonary fitness: engage in low-impact aerobic exercise (e.g., walking, cycling, or swimming) 2–3 times per week, while monitoring heart rate and tolerance.

If severe pain, significant joint swelling, or deterioration in function occurs during rehabilitation, seek medical evaluation promptly to avoid further tissue damage.

Special Considerations: If there is distant metastasis (especially to the lungs, bones, or central nervous system) or a decline in physical fitness due to chemotherapy or radiotherapy, exercise intensity and modality should be personalized under professional supervision to prevent overexertion.

Disclaimer: This report is for reference only based on the available information and does not substitute for an in-person consultation or professional medical advice. If you have concerns or if symptoms worsen, please consult a physician for further examination and evaluation.