Medical Imaging Analysis Report

1. Radiological Findings

Based on the right ankle images provided by the patient (including X-ray, color Doppler ultrasound, CT, and MRI), the following can be observed:

• X-ray plain film: Overall, the bony structures of the ankle joint appear relatively preserved. A protruding soft tissue mass shadow can be seen with generally clear margins; no obvious osseous destruction or bone erosion is noted. The ankle joint space is largely maintained.
• Color Ultrasound: Beneath the ankle joint and surrounding subcutaneous soft tissue layer, a hypo- or mixed-echoic mass can be observed with abundant blood flow signals, suggesting rich local blood supply.
• CT Scan: In the subcutaneous region of the right ankle, there is a soft tissue density lesion with relatively well-defined margins, and its density is approximately similar to the surrounding soft tissues. Post-contrast enhancement reveals moderate to marked enhancement with local lobulation, and no obvious bone erosion is found.
• MRI: On T1-weighted imaging, the lesion’s signal is similar to that of muscle (isointense). On T2-weighted images, it appears hyperintense. Post-contrast scans show marked heterogeneous or relatively homogeneous enhancement, consistent with fibrosarcoma-like or related soft tissue tumor features. There is no significant involvement of the joint cavity. Surrounding muscles and tendons can occasionally be compressed or slightly displaced.

2. Potential Diagnoses

Taking into account the patient’s age (63), clinical presentation (a slowly growing mass in the ankle area with a previous history of local surgery), and imaging findings, the potential or differential diagnoses include:

• Dermatofibrosarcoma protuberans (DFSP): Typically presents as a slowly growing subcutaneous or soft tissue tumor. MRI often shows iso-intense signal on T1, hyperintense signal on T2, with prominent enhancement. It can have a high recurrence rate. Combined with the CD34-positive immunohistochemical results in this case, it strongly suggests the diagnosis.
• Fibrosarcoma or other fibrous soft tissue neoplasms: They can exhibit similar histological features and enhancement patterns on imaging, but usually require pathological immunohistochemistry (e.g., CD34, S-100) for differentiation.
• Synovial sarcoma and other soft tissue sarcomas: They can also present as an enhancing soft tissue mass, but are more commonly seen in younger patients, and differ in pathological markers and clinical manifestations.
• Giant pigmented nevus or other cutaneous adnexal tumors: It cannot be completely ruled out based solely on imaging; however, their imaging features typically lack a rich vascular or fibrous component, and they are more easily distinguishable histologically.

3. Final Diagnosis

Combining the patient’s clinical history (including a similar previous surgical history, slow-growing mass with local recurrence), imaging findings (subcutaneous tumorous lesion, T2 hyperintensity, significant enhancement on contrast scan), and pathological histology showing the typical storiform arrangement of spindle cells and CD34 positivity on immunohistochemistry, the most likely diagnosis is:

Dermatofibrosarcoma protuberans (DFSP).

If there are further clinical concerns, additional pathological molecular tests (such as PDGFB gene rearrangement) may be performed intraoperatively or postoperatively to confirm the diagnosis.

4. Treatment Plan and Rehabilitation Program

• Treatment Strategy:
• Surgical Resection: DFSP is characterized by locally invasive growth. Wide surgical excision (including Mohs micrographic surgery) is the first choice to reduce the risk of local recurrence. Efforts should be made to preserve ankle joint function, and preoperative MRI can be used to assess the margins if necessary.
• Radiotherapy: If the surgical margins are unclear postoperatively or if obtaining a sufficiently safe margin is not possible, adjuvant radiotherapy can be considered.
• Molecular Targeted Therapy: For inoperable or recurrent cases, tyrosine kinase inhibitors (e.g., imatinib) may be considered, particularly in situations where complete local excision or distant metastasis management is difficult.
• Rehabilitation and Exercise Prescription Recommendations:
• Postoperative/Treatment Acute Phase (0-2 Weeks):
  • Protect the affected ankle to avoid heavy loads or excessive flexion and extension.
  • Light toe motion and non-weight-bearing active ankle movements can be performed to promote blood circulation.
• Recovery Phase (2-6 Weeks):
  • Gradually reduce or remove external support according to medical advice and perform ankle flexion and extension exercises.
  • Use the principle of “low intensity, high repetition” initially, starting with 1-2 sets of 10-15 repetitions per set, with relatively light intensity.
• Later Functional Training (6 Weeks to 3 Months):
  • Gradually increase range of motion and muscle strength training, such as tiptoe exercises and resistance training for plantarflexion/dorsiflexion and inversion/eversion of the ankle.
  • Continue with 2-3 sets per session, each set not limited to 10-15 repetitions, but proceed gradually without causing significant pain or swelling.
• Maintenance Phase (3 Months and Beyond):
  • Engage in higher-level strength and balance training, such as single-leg stands, balance board, and resistance band exercises.
  • Depending on cardiovascular and skeletal conditions, low-impact aerobic exercise (e.g., cycling, swimming) may be introduced 2-3 times per week for 20-30 minutes each session.
• Precautions:
  • Because of the patient’s advanced age, pay extra attention to bone quality and cardiopulmonary function to avoid complications from excessive exercise.
  • Perform appropriate ankle warming up and stretching before and after each session. If significant pain, swelling, or discomfort occurs, prompt medical consultation is advised.

Disclaimer: This report is for medical information reference only and cannot replace an in-person consultation or professional physician’s diagnosis and treatment advice. Please combine specific treatment plans and rehabilitation arrangements with actual clinical conditions and carry them out under the guidance of a professional physician.