An inflammatory pseudotumor in the thoracic epidural space presenting with progressive paraplegia: a histopathological diagnosis with clinical and radiological uncertainty. Case report with literature review

Abstract

Introduction: Inflammatory pseudotumors (IPTs) are benign lesions with unknown etiology, probably an immunological reaction to a traumatic or an infective insult or sometimes considered as an IgG4-related autoimmune disorder. It can occur as an isolated or multi-centric lesion and are reported to involve almost all parts of the human body. Although lung and orbital IPTs are reported commonly, central nervous system involvement is a rare occurrence. Only seven cases of spinal epidural IPTs have been reported to date. These are clinically and radiologically a diagnosis of exclusion. It is an exclusive histopathological diagnosis.

Case report: We present here a 49-year-old female with 2 months history of progressive weakness in lower limbs, with no history suggestive of any traumatic, infective, inflammatory, or neoplastic pathology. Both clinical and radiological investigations were inconclusive. There was a mass lesion in the epidural space (predominantly in the posterior and right lateral space) at T1-T3 vertebral levels compressing the thoracic spinal cord. Considering the progressive nature of her neurological deficit, an emergency decompressive laminectomies of T1-T3 vertebrae were done with excision of the compressive mass lesion. Histopathological examination showed a rich lympho-plasmacytic cell infiltrates with storiform spindle cells and dense fibrosis, which was diagnostic of IPT. Post-operatively there was a rapid recovery in neurology and she became ambulatory at the end of 2 weeks. The purpose of this case report is to discuss the clinical, histopathological and radiological features, differential diagnosis, management, and prognosis of spinal IPT on the background of relevant literature review.

Keywords: Decompressive laminectomies; Fibro-inflammatory; IgG4; Inflammatory pseudotumor; Lympho-plasmacytic infiltrates.