I. Radiological Findings

The patient is a 61-year-old male who presented with nonspecific rib pain. During an abdominal-pelvic CT scan, an incidental finding was discovered under the cortical layer of the right iliac bone: a fusiform or lenticular lesion. Based on the provided CT, MRI, and X-ray images:

• The lesion is located between the periosteum and the cortical bone, appearing as a lens-shaped area with a smooth margin and a clear sclerotic rim.
• On CT, there is a slightly hyperdense linear sign separating the lesion from normal bone marrow, suggesting the “native cortical ghost” phenomenon.
• No obvious cortical infiltration or marrow involvement is seen, and the overall integrity of the bone is maintained.
• No significant swelling or abnormal soft tissue mass is detected around the lesion, and there is no clear sign of nerve or vascular compression on imaging.
• On MRI T1 and T2 sequences, the lesion shows heterogeneous signals internally, possibly indicating an old hematoma and fibrotic components.

In summary, this lesion has the characteristic “smooth sclerotic rim” and “native cortical ghost” finding, which is consistent with a chronic subperiosteal (subcortical) hematoma of the iliac bone.

II. Potential Diagnoses

Based on clinical and radiological features, the following diagnoses or differential diagnoses should be considered:

1. Chronic Subperiosteal Hematoma of the Iliac Bone:
   • Often results from blunt trauma in younger years, causing separation between the periosteum and cortical bone, leading to hematoma formation.
   • May gradually organize and calcify, resembling an osteoma or tumor-like lesion.
   • Characteristic radiological features include a lenticular shape, smooth sclerotic rim, and a distinct “native cortical ghost” sign delineating it from normal bone marrow.
2. Osteoma or Tumor-like Lesions:
   • Osteomas are more commonly seen in the skull or facial bones, but can appear in long bones or the ilium. They typically grow slowly, have uniform density, and maintain continuity with surrounding bone.
   • If density and structure are very uniform with overly neat boundaries, an osteoma must be considered.
3. Hyperostosis or Hypertrophic Periosteal Reaction:
   • Chronic inflammation or repetitive stress can lead to local periosteal thickening, but it often displays irregular texture or outward expansion. Newly formed cortical bone typically lacks a distinct boundary from the marrow.

III. Final Diagnosis

Considering the patient’s age, possible history of trauma during youth, current imaging findings, and minimal or no significant clinical symptoms, the most likely diagnosis is:

Chronic Subperiosteal Hematoma of the Iliac Bone.

This is a rare benign pathological condition, often caused by previous trauma. It is frequently discovered incidentally during check-ups or imaging performed for other reasons, and typically does not require additional invasive procedures for confirmation.

IV. Treatment Plan and Rehabilitation

1. Treatment Strategies:

• Conservative Management: For asymptomatic patients, observation and follow-up imaging may be sufficient. If the lesion remains stable and does not compress nerves or blood vessels, and does not affect daily function, no specific intervention is necessary.
• Interventional or Surgical Procedures: If the lesion significantly enlarges or causes notable pain or neurological symptoms (e.g., involving femoral or obturator nerves), drainage or surgical removal of the lesion may be considered, along with periosteal repair or nerve decompression if needed.
• Pharmacological Support: For pain or discomfort, a short course of appropriate analgesics (e.g., NSAIDs) may be used, with caution regarding gastrointestinal and cardiovascular side effects.

2. Rehabilitation/Exercise Prescription (FITT-VP Principle):

• Frequency: 3–4 times per week, adjusted according to the patient’s physical condition and joint status.
• Intensity: Begin with low to moderate intensity exercises (e.g., brisk walking, cycling) and avoid high-impact activities.
• Time: Start with 20–30 minutes per session and gradually increase to 40–60 minutes, based on tolerance and absence of discomfort.
• Type:
  • Low-impact aerobic activities such as swimming, stationary cycling, or using an elliptical trainer.
  • Progressively include core and lower limb strengthening exercises to maintain good muscle strength and stability.
• Progression: After 2–4 weeks, if no exacerbation of pain or discomfort occurs, increase exercise duration or intensity by about 10–15% every 1–2 weeks.
• Volume & Individuality: Encourage patients to adjust their exercise program based on daily status and medical advice. If noticeable discomfort or pain arises, reduce exercise volume or pause temporarily and consult a professional if necessary.

During rehabilitation, exercise form should be closely monitored to avoid excessive stress on the hip or lumbar spine. Patients with osteoporosis, hypertension, or compromised cardiopulmonary function should exercise under professional supervision to ensure safety.

Disclaimer

This report is based on the limited medical history and radiological data provided by the patient. It is intended for clinical reference only and should not replace an in-person diagnosis or professional medical advice. If you have any concerns or notice any changes in symptoms, please consult a specialist or visit a hospital promptly.