Background:
With an estimated incidence of about 1 case/million patients, paravertebral intramuscular myxomas represent a rare cause of lumbar pain. Rather, they typically occur in the heart and in bone tissues.
Case description:
A 64-year-old female presented with a protracted course of nocturnal lumbar pain that radiated to the anterior aspect of the right thigh accompanied by numbness. She reported a slow-growing right paramedian lumbar mass in the previous months. The magnetic resonance (MR) showed a right lumbar paravertebral intramuscular mass at the L3 level (i.e., 70 × 50 mm) that had well-defined margins, and markedly enhanced with gadolinium. Following gross total "en bloc" tumor resection, the patient fully recovered. Pathologically, the myofibroblastic lesion proved to be an intramuscular myxoma without malignant changes.
Conclusion:
A 64-year-old female presented with a slow-growing MR-documented right paramedian lumbar L3 mass responsible for proximal right-thigh numbness. Following "en bloc" gross total removal of the benign intramuscular myxoma, the patient was asymptomatic.