IgG4 Licks base of skull, wastes tongue: An unusual presentation

IgG4 Related disease (IgG4 RD) is a rapidly evolving clinical entity, involving multiple organs, manifesting clinically as tumefactive lesions, histopathologically characterized by an IgG4 predominant, dense lymphoplasmacytic tissue infiltrate. It might mimic malignancy, infection as well as various other inflammatory disorders. First described in literature in 2003, in the pancreas, it has been subsequently seen to involve a wide range of organs like salivary glands, paranasal sinuses, thyroid gland, retroperitoneum, lung and kidney. Rarely, it may present as a skull base osteomyelitis (SBO). Diagnosing IgG4 RD in such patients is a herculean challenge in view of absence of systemic symptoms, difficulty in obtaining adequate tissue specimens in view of densely fibrotic cranial base lesions, as well as the close proximity of the lesions to critical neurovascular structures. The standard of care, in such cases is medical, and comprises of steroids and rituximab. Herein, we discuss one such case of IgG4 RD, who presented as multiple lower cranial nerve palsies and headache, with imaging evidence of SBO, which was diagnosed as a case of IgG4RD on histopathology, and who despite receiving the standard of care, had a poor outcome. The purpose of presenting this case is to stress upon a high index of suspicion and an aggressive management approach while treating such cases