Medical Imaging Analysis Report

I. Imaging Findings

The patient is a 49-year-old male with a large soft tissue mass observed subcutaneously in the lower abdominal area (suprapubic region). Based on the provided CT, ultrasound, and MRI images, the main imaging characteristics include:

• CT Scan: The mass appears as a soft tissue density lesion with relatively clear boundaries, located in the superficial subcutaneous layer. Local subcutaneous bulging can be seen, and no obvious deep infiltration is identified at present.
• Ultrasound Examination: The lesion has a regular shape and relatively clear margins. Internal blood flow signals are detected (color Doppler indicates blood flow around and within the lesion). The internal echoes are not homogeneous, showing partially hypoechoic areas.
• MRI Examination: The lesion shows relatively homogeneous low signal intensity on T1WI. On T2WI and fat-suppressed sequences, slightly high-signal reticular structures are visible. After contrast enhancement, the lesion exhibits ring-like or peripheral enhancement, suggesting possible necrosis or cystic components in the center. The lesion as a whole has a well-defined boundary, and there is no significant bone destruction or signs of involvement of the deep fascia or muscle layer.

II. Differential Diagnoses

Based on the patient’s middle age, recent rapid growth of the lesion, and imaging findings, possible diagnoses include:

1. Skin Adnexal Tumor (e.g., Pilomatrix Carcinoma)
   Reasoning: This tumor commonly occurs in middle-aged and elderly individuals, often presenting as a subcutaneous mass. Although rare, it may exhibit rapid growth. Imaging can show a relatively well-defined boundary with areas of necrosis, calcification, or cystic changes.
2. Benign Pilomatrixoma
   Reasoning: Originating from the same source as malignant pilomatrix carcinoma, but it generally grows more slowly, with fewer malignant features such as rapid growth or histological changes. If imaging and histology suggest benign characteristics but there is suspicion of atypical cell growth, further differentiation is needed.
3. Other Soft Tissue Sarcomas (e.g., liposarcoma, malignant fibrous histiocytoma, etc.)
   Reasoning: These may also present as soft tissue masses with rapid growth. However, imaging typically demonstrates more pronounced infiltration, heterogeneous signals, and unclear boundaries with surrounding tissues.
4. Metastatic Subcutaneous Nodule
   Reasoning: Metastatic tumors to the subcutaneous tissue can form nodules, but usually there is a known primary tumor and relevant medical history. Currently, no primary lesion is indicated in this patient, making this diagnosis less likely.

III. Final Diagnosis

Combining the patient’s age, recent rapid enlargement, the imaging findings, and biopsy results indicating malignant features (including cellular atypia and high mitotic activity), the most likely diagnosis is:

Pilomatrix Carcinoma (Malignant Pilomatrixoma).

As this condition is quite rare, further confirmation with complete surgical pathology and immunohistochemistry may be necessary if there is still doubt. Wide local excision is recommended, and adjuvant treatment (such as radiotherapy) should be considered based on the postoperative pathology.

IV. Treatment Plan and Rehabilitation

1. Treatment Strategy:

• Surgical Treatment: For malignant pilomatrixoma, wide local excision (ensuring adequate margins) is the treatment of choice. If postoperative pathology indicates a high risk of recurrence or metastasis, adjuvant radiotherapy may be considered.
• Radiotherapy: For lesions with unclear margins or high-risk features, postoperative radiotherapy may reduce local recurrence rates.
• Chemotherapy: Generally not common, primarily determined by the pathological stage, recurrence risk, and the overall condition of the patient.

2. Rehabilitation and Exercise Prescription:

Postoperative rehabilitation should consider the extent of resection and wound healing. It is advised to proceed progressively, following the FITT-VP principle (Frequency, Intensity, Time, Type, Volume, Progression, and Pattern).

1. Early Stage (2–4 weeks post-surgery)
   Main Goal: Reduce pain, promote incision healing, and maintain joint range of motion.
   • Low-intensity exercises 3–5 times per week, such as gentle range-of-motion exercises around the surgical site and walking.
   • Each session lasts about 10–15 minutes, depending on tolerance. Avoid excessive stretching of the surgical area.
2. Intermediate Stage (4–8 weeks post-surgery)
   Main Goal: Strengthen soft tissue recovery and prevent loss of muscle strength and coordination.
   • Gradually increase exercise frequency to 4–6 times per week. Incorporate moderate-intensity resistance exercises (e.g., light resistance band training), avoiding excessive stress on the surgical site.
   • Each session lasts about 20–30 minutes. Monitor for redness or discomfort around the surgical site and adjust intensity as needed.
3. Late Stage (8 weeks post-surgery and beyond)
   Main Goal: Achieve full functional recovery and continue to prevent recurrence or complications.
   • Add endurance training (e.g., brisk walking, light jogging) 3–5 times per week. Intensity can be increased to moderate or slightly higher levels.
   • Each session lasts about 30–45 minutes, combined with core strengthening and balance/coordination exercises to ensure safety and effectiveness.
4. Individual Adjustments: For patients with chronic conditions (e.g., hypertension, poor cardiopulmonary function) or those with fragile bones or slower soft tissue healing, exercise methods and intensity should be modified under the guidance of a doctor or rehabilitation therapist. Additional rest days may be necessary.

By following this step-by-step recovery and exercise plan, along with regular follow-up, patients can improve postoperative functional outcomes and reduce the risk of recurrence.

V. Disclaimer

This report is a preliminary analysis based on the current imaging and pathological information, provided for clinical reference only. It cannot replace in-person consultation or professional medical advice. If there are any questions or changes in symptoms, please consult a relevant specialist or visit a hospital for further examination and treatment.