Medical Imaging Analysis Report

I. Radiological Findings

According to the provided contrast-enhanced CT images, a noticeable soft tissue mass with relatively well-defined boundaries is observed in the left thigh. On non-contrast scans, the lesion appears slightly hyperdense or isodense, while post-contrast images show relatively uniform enhancement. No evident adjacent bone destruction or periosteal reaction is seen. The surrounding muscular structures are essentially intact, and no obvious signs of bony invasion are noted at this stage.

Clinically, the patient describes the mass as having a “slightly firm (ligneous consistency), mobile, and painless” nature. The location of the mass and its relatively uniform enhancement suggest the possibility of a benign soft tissue lesion.

II. Potential Diagnoses

1. Nodular Fasciitis (NF):
   • Pathological characteristics: Often caused by proliferating fibroblasts; presents as a pseudo-tumor growth but is benign in nature.
   • Clinical features: Can exhibit rapid growth and a benign course but may resemble a malignant lesion in appearance. It is commonly found in the proximal regions of the limbs and can also occur in the trunk or head and neck regions.
   • Imaging features: On CT, typically shows a relatively well-defined soft tissue mass. After contrast, it displays uniform or mildly heterogeneous enhancement. On MRI, it often appears slightly hyperintense or isointense on T1, hyperintense on T2, with marked enhancement.
2. Lipoma or Fibrolipoma:
   • Usually benign soft tissue tumors composed mainly of adipose tissue, and they appear as low-density areas on CT.
   • If fibrous tissue or other soft tissue components are mixed in with fat, the density can appear somewhat heterogeneous.
3. Soft Tissue Sarcomas (e.g., Synovial Sarcoma, Malignant Fibrous Histiocytoma, etc.):
   • Presents as a soft tissue mass that can show invasive growth, often accompanied by pain or surrounding tissue destruction.
   • On CT or MRI, the lesion may demonstrate poorly defined margins and typically heterogeneous enhancement; necrosis or hemorrhage may also be visible.

III. Most Likely Final Diagnosis

Considering the patient’s age (60 years), clinical presentation (a painless, mobile mass in the left thigh), the soft tissue characteristics with relatively well-defined and moderately homogeneous enhancement on imaging, and the fact that nodular fasciitis can appear as “pseudo-sarcomatous” proliferation on imaging—exhibiting rapid growth but still representing a benign process—the most likely diagnosis is Nodular Fasciitis (Nodular Fascitis).

For definitive confirmation, an image-guided core needle biopsy or surgical excision followed by pathological examination may be considered to clarify the nature of the lesion.

IV. Treatment Plan and Rehabilitation

Treatment Strategy:

• Surgical Excision or Biopsy: Since nodular fasciitis is usually benign but can be difficult to distinguish from malignant soft tissue tumors, a limited surgical excision or biopsy can be performed to confirm the diagnosis. If nodular fasciitis is confirmed, complete surgical resection typically yields a favorable prognosis with low recurrence rates.
• Conservative Follow-Up: For lesions that are small in size and minimally symptomatic, periodic follow-up under the guidance of a specialist may be considered. Some cases of nodular fasciitis may be self-limiting.

Rehabilitation/Exercise Prescription Suggestions (FITT-VP Principle):

1. Type of Exercise (Type):
   • In the early postoperative stage, gentle range-of-motion exercises of the lower limb and isometric muscle contractions are recommended to minimize local adhesions.
   • In the mid-to-late stage, gradually introduce resistance training and flexibility exercises, coupled with low-impact aerobic activities (such as brisk walking or cycling).
2. Frequency of Exercise (Frequency):
   • Early stage: 3–4 times per week, focusing on restoring range of motion and preventing adhesions.
   • Mid-to-late stage: Gradually increase to 4–5 times per week, adjusted according to individual tolerance.
3. Exercise Intensity (Intensity):
   • Early stage: Low-intensity exercises (perception of minimal fatigue), avoiding strenuous movements or excessive stretching.
   • Mid-to-late stage: Increase resistance or target heart rate in a safe manner (e.g., keeping the target heart rate at around 50%–60% of the maximum heart rate).
4. Exercise Duration (Time):
   • 20–30 minutes per session is recommended initially, divided into segments according to physical capacity and comfort.
   • As recovery progresses and tolerance improves, gradually increase to 30–45 minutes per session.
5. Total Volume (Volume) and Progression (Progression):
   • In different stages of postoperative recovery and rehabilitation, it is crucial to proceed gradually and avoid excessive training at once.
   • The total exercise volume can be increased by adding more sessions per week or extending each session’s duration, while carefully monitoring for pain or other adverse symptoms.

V. Disclaimer

This report provides an academic and reference-based analysis derived from the available clinical history and imaging data. It is not a substitute for in-person medical diagnosis or individualized medical advice. If you have any concerns or experience any changes in symptoms, please seek prompt medical attention or consult a qualified healthcare professional.