Spinal epidural abscess mimicking lymphoma: a case report.

We describe a case of epidural thoracic abscess presenting similar to epidural lymphoma on imaging and review the imaging findings and clinical characteristics of both to help differentiate the two. Typical magnetic resonance imaging characteristics for epidural abscess are a heterogeneously enhancing epidural collection, which is isointense/hypointense on T1 images and hyperintense on T2 images with granulation tissue typically having a rim of enhancement with gadolinium. In contrast, typical imaging characteristics for an epidural lymphoma include an isointense/hypointense appearance on T1-weighted magnetic resonance imaging (MRI) and a hyperintense or even hypointense appearance on T2 images. Lymphomas tend to enhance uniformly and diffusely with contrast. The patient's MRI revealed a compressive thoracic epidural mass at T8-T10. The mass was hypointense on T1- and T2-weighted images and enhanced intensely and uniformly on T1 images after gadolinium injection. Additionally, abnormal hyperintense signal within the left T9-T10 facet joint was identified on T2 images. The imaging findings were felt to be most consistent with lymphoma, but the possibility of epidural abscess, and less likely, epidural hematoma were also considered. Although the patient's abscess presented similar to lymphoma on MRI, possibly the most revealing clue on imaging that infection was the likely diagnosis was hyperintense signal within the left facet joint seen on T2-weighted images. This is important as primary radiation treatment based on imaging characteristics alone, without a tissue diagnosis, is often suggested in cases of lymphoma. This mode of treatment would be contraindicated in the setting of infection. A diagnosis that is not conclusive by needle biopsy or imagine may require an open procedure for definitive diagnosis.