Imaging Findings

The patient is a 2-year-old girl presenting with chest wall swelling, slightly limited mobility of the left hand, a short and thick neck, and multiple hard, non-tender subcutaneous nodules on the back. From the provided imaging studies (including X-ray films of the cervical spine, limbs, and feet), the following findings are noted:

• Ossification observed in the local soft tissues of the cervical spine; partial fusion or limited mobility of some cervical facet joints (C2–C7).
• Ectopic ossifications in the subcutaneous tissues of the back, appearing as band-like or patchy high-density lesions with clear boundaries from the surrounding soft tissue.
• Significant hallux valgus deformity of the first metatarsophalangeal joint, coexisting with soft tissue ossification.
• The hand X-ray shows abnormalities of the thumb or first metacarpal, as well as some soft tissue calcification/ossification.
• The overall shape of the bones is relatively preserved with no obvious signs of bone destruction or fracture, but multiple ectopic bone formations are present in the soft tissue.

Potential Diagnoses

Based on the patient’s age, clinical symptoms, and imaging findings, the potential diagnoses include:

1. Fibrodysplasia Ossificans Progressiva (FOP):
   Classically characterized by progressive ectopic ossification in soft tissues, commonly starting with the neck muscles (such as the sternocleidomastoid). It is often associated with a deformity of the first toe (e.g., hallux valgus or abnormal first metatarsal), and imaging typically shows multiple, progressive sites of soft tissue ossification.
2. Progressive osteogenic fibroma or other rare soft tissue ossification disorders:
   Although also presenting with soft tissue calcification or ossification, these conditions often lack the characteristic hallux valgus deformity and spinal joint fusion seen in FOP.
3. Post-traumatic ectopic ossification / Myositis ossificans:
   Usually associated with trauma or repetitive injury; the bone formation is often localized. In this case, absence of a clear trauma history, along with multifocal lesions and clinical/genetic background, is more suggestive of FOP.

Final Diagnosis

Taking into account the patient’s age, clinical signs (short neck, multiple hard nodules in soft tissues, limited joint mobility, hallux valgus deformity) and radiographic findings (partial cervical spine fusion, extensive ectopic ossification in soft tissues, first toe deformity), the most likely diagnosis is Fibrodysplasia Ossificans Progressiva (FOP).

This rare autosomal dominant genetic disorder typically avoids histopathological examination (biopsy) as trauma may trigger or worsen ectopic ossification. If further confirmation is required, genetic testing under the guidance of a specialist is advised.

Treatment Plan and Rehabilitation Program

Treatment Strategy:

• Symptomatic and supportive treatment: Currently, there is no specific cure. Short-term use of NSAIDs or corticosteroids may be considered during acute inflammatory phases (e.g., local swelling, redness) to alleviate discomfort.
• Avoid trauma and unnecessary surgeries or biopsies: Surgical intervention can exacerbate ectopic bone formation.
• Specialist follow-up: Regularly assess the progression of ossification and monitor joint range of motion. Seek expert opinions for significant functional limitation or severe pain.

Rehabilitation and Exercise Prescription Suggestions (FITT-VP Principle):
Given the patient’s young age and the high risk of muscle and ligament ossification, a safe, low-load, and individualized program is recommended:

• Frequency (F): 1–2 times per week, conducted in a safe environment under parental supervision, with careful observation of the child’s response.
• Intensity (I): Low intensity. Avoid forceful stretching or high-intensity strength training. Simple active or passive movements within a comfortable range are recommended.
• Time (T): 5–10 minutes per session, which can be extended based on the child’s tolerance.
• Type (T): Focus on maintaining joint range of motion and basic posture management, such as gentle passive/active joint activities and mild stretching. Avoid high-impact exercises or those prone to causing trauma from falls or collisions.
• Progression (P): If the child experiences no significant discomfort with the current exercises, gradually increase the frequency or activity range. Monitor closely for any new pain or swelling to prevent aggravation.

Enhanced safety measures are critical during rehabilitation because of the high risk of ossification. High-impact or excessive stretching exercises are not advised. Parents should participate in supervision and maintain regular communication with rehabilitation therapists and orthopedic/pediatric specialists to adjust the training plan.

Disclaimer

This report is based on a review of the provided case history and imaging data for reference purposes only, and it does not substitute an in-person diagnosis or treatment recommendation by a qualified physician. If there are any concerns or if the patient’s symptoms worsen, please seek medical attention promptly and follow specialist guidance.