Medical Imaging Analysis Report

I. Radiological Findings

Imaging reveals a localized soft tissue mass in the right thigh, measuring approximately 10 cm, with distinct borders. The main findings from each examination are as follows:

• CT: A mass primarily showing fatty density shadow, closely attached to the cortical surface of the femur, with local bone proliferation-like changes observed. No clear evidence of bone marrow invasion.
• MRI: The lesion shows a prominent fat signal on T1 and T2-weighted images, featuring a small amount of low-signal fibrous septa. The lesion is attached to the adjacent bony cortex; in some slices, irregular bony protrusions are visible, but there is no continuity with the medullary cavity.
• X-ray: A well-defined soft tissue mass shadow is seen adjacent to the femur, with superficial new bone-like changes locally.

Overall, the lesion presents a typical fatty component signal/density and appears closely related to the bony cortex, suggesting a parosteal adipocytic lesion.

II. Potential Diagnoses

• Parosteal Lipoma
  This represents a very rare type of lipoma, accounting for about 0.3% of all lipomas. Its hallmark is the proliferation of adipose tissue on the cortical surface of the bone, which can be accompanied by local bone proliferation or cortical reactions. Radiologically, the mass is almost entirely composed of fatty density and is the primary consideration.
• Liposarcoma
  A malignant adipocytic tumor. On imaging, it often appears as an irregular soft tissue mass with varying degrees of solid components or thickened septations. Its presentation on the surface of the bone is relatively uncommon.
• Soft Tissue Sarcoma
  If the lesion shows extensive invasiveness or predominantly non-fat components on imaging, other types of soft tissue sarcomas should be ruled out. However, given the findings in this case—mainly fatty density with clear margins—this possibility is low.

III. Final Diagnosis

Taking into account the patient’s age, clinical presentation (painless soft tissue mass), radiological findings (fatty density or signal, attachment to the cortical bone, local bone proliferation), and pathological examination results, the most likely diagnosis is:

Parosteal Lipoma.

A CT-guided biopsy and pathological confirmation have been performed, confirming the benign adipocytic nature of the lesion.

IV. Treatment Plan and Rehabilitation Program

Treatment Strategies:

• Surgical Treatment: In cases where there are significant local symptoms or functional limitations (e.g., pain, nerve compression, or muscle dysfunction), complete surgical resection may be considered. As this condition is benign, it can often be completely removed.
• Conservative Observation: If it is an incidental finding without symptoms and with no significant enlargement trend, periodic follow-up can be considered without immediate surgery.

Rehabilitation/Exercise Prescription Recommendations:

If the patient undergoes surgical resection, a rehabilitation plan should be established based on the postoperative condition. If opting for conservative management, moderate functional exercises are recommended to maintain muscle strength and joint mobility.

1. Early Postoperative Phase (Weeks 1–2):
   • Focus on isometric contractions and gentle range-of-motion exercises, such as slow knee flexion/extension and ankle pumping to improve local blood circulation.
   • Avoid heavy or intense activities to prevent traction pain in the surgical area.
2. Mid Postoperative Phase (Weeks 3–6):
   • Gradually increase load with exercises like sit-to-stand drills and straight-leg raises to enhance lower limb strength.
   • Exercise frequency of 3–4 times per week for 20–30 minutes each session, with intensity based on “no significant pain or fatigue.”
3. Late Postoperative Phase (After Week 6):
   • Under the guidance of a physician or rehabilitation therapist, gradually add low-intensity resistance exercises (e.g., resistance bands, moderate weight training).
   • Follow the FITT-VP principle (Frequency, Intensity, Time, Type, Volume, and Progression) and adjust incrementally depending on individual recovery.
4. Conservative Management:
   • Perform moderate bodyweight or low-resistance exercises, such as static squats and lower limb stretching to strengthen muscles and maintain joint flexibility.
   • If any new onset of pain, increase in mass size, or sensory or motor deficits occur, consult a physician promptly.