Bone edema of the whole vertebral body: an unusual case of spondyloarthritis.

Spondyloarthritis (SpA) is usually characterized by early inflammatory involvement of the sacroiliac joints (SI), which constitutes one of the most important classification criteria according to the SpondyloArthritis International Society (ASAS). These criteria do not include inflammatory spine lesions which can be detected on MRI, although spine involvement is very common in axial SpA. This is because spine MRI lesion often retrieved in SpA are not very specific, and can be found in many other diseases such as malignancy and osteoarthritis. Here we present the case of a 33-year old woman who presented a worsening low back pain, with a thoracic spine MRI showing bone marrow edema (BME) of the whole T8 vertebral body. Owing to this peculiar presentation, together with the unresponsiveness of the pain to nonsteroidal anti inflammatory drugs (NSAIDs) and a slight increase of the biomarker CA19-9, a malignancy was suspected. Therefore, the patient underwent bone scintigraphy, Single positron emission computed tomography (SPET/TC), positron emission tomography and repeated MRI without reaching a diagnosis. Finally, when SI joints MRI was performed, BME of the SI joints emerged: this was fundamental to formulate the diagnosis of axSpA.