Pseudotumor Tensor Fascia Lata Syndrome From Underlying Severe Lumbar Stenosis: A Case Report

A pseudotumor of the tensor fascia lata (TFL) describes a rare condition characterized by hypertrophy or pseudohypertrophy of the TFL that can mimic a soft tissue mass. Without the right clinical suspicion, it can be misdiagnosed as a benign or malignant soft tissue tumor, leading to oncologic workups. Unnecessary workups can cause patient distress, waste resources, and delay the management of the condition and its associated symptoms. Here, we describe a 65-year-old male who developed a pseudotumor of the TFL in the setting of severe lumbar spinal stenosis. The etiology for this patient was suspected to be a combination of altered gait mechanics and denervation secondary to L4/5 radiculopathy. There is a paucity of current research, literature, and clinical cases on this topic. However, the prior cases share similarities in presentation and imaging findings. Magnetic resonance imaging (MRI) is the gold standard for diagnostic confirmation in nearly all cases, with treatment ranging from hip abductor strengthening to botulinum toxin injections. To limit unnecessary diagnostic testing and invasive procedures, it is important for clinicians to be aware of TFL hypertrophy and its possible etiologies.