Medical Imaging Analysis Report

1. Imaging Findings

This case involves a 17-year-old male patient who complains of a painless, slowly enlarging mass around the knee joint. Routine X-ray examinations show no significant abnormal findings. MRI findings indicate:

• Lobulated or band-like high-signal intensity in the soft tissue around the knee with relatively clear boundaries; in some areas, slender tubular structures are observed.
• On T1WI, the lesion mostly appears as isointense or slightly hypointense, whereas on T2WI or PD-weighted images, it shows markedly high signal. Localized “flow void” phenomena suggest fast-flow vascular channels.
• The lesion may extend along muscle fibers or the synovium of the joint, involving surrounding soft tissue; some regions exhibit septation and multifaceted compartments.
• No evidence of bone destruction or significant periosteal reaction; no notable abnormalities on the articular surface or cartilage.

2. Possible Diagnoses

Based on the above imaging findings and the patient’s history, the following diagnoses or differential diagnoses can be considered:

1. Synovial Hemangioma or Intramuscular Hemangioma (Soft Tissue Hemangioma)
   Characteristics: Commonly seen near joints or within muscles. On MRI, the hemangioma components show high signal, particularly on T2-weighted images, with possible flow void phenomena. These features align well with the vascular high-signal manifestations in this case.
2. Arteriovenous Malformation (AVM)
   Characteristics: Often presents with tubular flow void signals as well, more commonly related to congenital vascular malformations or significant hemodynamic changes, frequently accompanied by a disorganized vascular network. Although some high-flow vessels are seen in this case, the overall morphology is more consistent with a hemangioma.
3. Other Soft Tissue Tumors
   Examples include lipoma, schwannoma, or sarcoma. However, based on their typical MRI features (e.g., lipomas showing high signal on T1WI, schwannomas typically running along nerve bundles, malignant tumors often accompanied by destructive or invasive signs), they differ significantly from the lesion presented in this case.

3. Final Diagnosis

Considering the patient’s age (adolescent), clinical presentation (painless, slowly growing mass), and typical MRI vascular signals (high signal with flow void phenomena), the most likely diagnosis is Synovial Hemangioma or Soft Tissue Hemangioma. Further confirmation will be sought by interventional embolization outcomes and intraoperative/postoperative pathological examination.

4. Treatment Plan and Rehabilitation

Potential treatment options include:

• Surgical Resection: For cases affecting function or with cosmetic concerns, complete local resection can be considered. If necessary, interventional embolization may be performed beforehand to reduce intraoperative bleeding.
• Interventional Therapy (Embolization): For extensive lesions or those with higher surgical risk, preoperative embolization can shrink the lesion and reduce surgical complications. If surgery is not feasible, embolization may serve as a primary or adjunct therapy.
• Radiation Therapy: In a small number of cases that are difficult to excise or recur after resection, radiation therapy may be considered. However, its use in adolescents requires careful evaluation.

Rehabilitation and exercise recommendations:

• Early Stage/Postoperative Early Phase: Focus on protecting joint function and avoiding excessive weight-bearing or strenuous activities. Simple range-of-motion exercises, such as flexion and extension of the knee in a seated or supine position, are recommended to maintain soft tissue flexibility. Perform 3–4 sessions a day, each lasting 5–10 minutes.
• Mid-Phase Rehabilitation: After wound healing and relief of local pain and swelling, gradually introduce light weight-bearing exercises, such as straight leg raises or partial squats. Start with low intensity and progress to moderate, performing each session for 10–15 minutes, 3–5 times a week, depending on joint tolerance.
• Late Advanced Stage: Once the lesion site is largely stable, progressively add resistance training (using resistance bands or light weights) and low-impact aerobic activities (e.g., cycling or swimming). Maintain a frequency of 3–5 times per week for 20–30 minutes, adjusting load as tolerated by the individual.

Throughout the rehabilitation process, pay attention to:

• Closely monitor local swelling, pain, or restricted movement. Seek medical advice promptly if any significant discomfort or changes in the mass occur.
• Adhere to an individualized approach, with adjustments based on the patient’s cardiopulmonary function, muscle strength, and joint stability.
• Maintain good posture to prevent compensatory movements or secondary injuries.

Disclaimer: This report is based on the current imaging and clinical information for reference only and cannot replace a face-to-face consultation or professional medical opinion. The final determination of diagnosis and treatment plans requires clinical examinations, surgical findings, and pathological results. Patients should proceed with subsequent treatment and rehabilitation under the guidance of a qualified medical institution.