Pediatric Obturator Internus Muscle Myxoma

Area of Science:

• Oncology
• Pediatric Medicine
• Radiology

Background:

• Intramuscular myxoma is a rare, benign tumor typically affecting adults, characterized by slow growth within skeletal muscle.
• Histological features resemble umbilical cord tissue, and it predominantly affects individuals aged 40-70, with a slight female predilection.
• Pediatric cases are exceptionally rare, with limited literature documenting their occurrence.

Observation:

• A 13-year-old female presented with right hip pain, fever, and elevated inflammatory markers, initially suspected as septic arthritis or osteomyelitis.
• Pelvic MRI revealed a well-defined, enhancing lesion in the obturator internus muscle.
• Diagnosis was confirmed via CT-guided core biopsy.

Findings:

• The patient was diagnosed with a pediatric pelvic intramuscular myxoma, an extremely rare condition in this age group.
• Conservative management led to symptom improvement, with the patient remaining well at 2-year follow-up.
• The lesion's presentation mimicked more severe conditions like septic arthritis, osteomyelitis, and pelvic abscess.

Implications:

• This case underscores the importance of considering rare diagnoses like intramuscular myxoma in the pediatric differential diagnosis for hip pain.
• Early and accurate diagnosis is crucial to avoid unnecessary aggressive treatments for potentially benign conditions.
• Further research into pediatric intramuscular myxoma presentations and management is warranted.