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.

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.