IgG4-related Pachymeningitis as a Cause of Spinal Epidural Compression: Can Intraoperative Frozen Sections Predict the Underlying Pathology?

At times, spinal lesions are part of systemic manifestations of autoimmune disease. Awareness regarding their clinicopathological spectrum, particularly the lesions which usually respond to steroids/immunotherapy, is essential to avoid unwanted surgical morbidity. We discuss a case of a young-man presenting with thoracic spinal epidural compressive lesion which was indeed a manifestation of IgG4-related hypertrophic pachymeningitis. The mass was firmly adherent to the dura and extended into left neural foramen/paravertebral space which precluded complete excision. Frozen sections suggested fibro-inflammatory stroma with large areas of fibrosis and lymphoplasmacytic infiltrate. After subtotal excision, the patient improved with medical therapy at 1-year follow-up. Although uncommon, the case highlights the need to consider spinal presentation of this rare entity, especially in the context of autoimmune disorders or even in isolation. In this regard, intraoperative frozen section can hint the underlying inflammatory/autoimmune pathology, guide further course of surgery as well as limit unwarranted operative morbidity.