Objective:

To characterize an uncommon, yet debilitating, immune-mediated demyelinating disorder of unknown etiology in three pediatric patients. 

Background:

Tumefactive demyelinating lesions (TDLs) are large lesions (>2 cm) seen in demyelinating syndromes such as multiple sclerosis, MOG antibody disease, and neuromyelitis optica. TDLs can cause severe presentations given their size, edema and associated mass effect, making prompt diagnosis and effective treatment crucial. We present three patients with severe relapsing TDLs who did not meet criteria for a known demyelinating syndrome. 

Design/Methods:

Retrospective chart review of three patients with nonsyndromic relapsing TDLs. 

Results:

Three adolescents between 15 to 17 years old without significant underlying medical history presented independently with a range of symptoms including headache, emesis, seizures, and altered mental status with imaging revealing large TDLs and negative serum and cerebrospinal fluid workup for known demyelinating disorders such as MOGAD, NMO and MS. All three patients initially improved with a combination of high dose intravenous methylprednisolone (IVMP), intravenous immunoglobulin (IVIG) and/or plasma exchange (PLEX). However, our first two patients had multiple subsequent relapses characterized by new focal symptoms including seizures, motor weakness, diplopia, and cranial nerve palsies associated with the appearance of larger existing TDLs and new discrete TDLs despite long term IVIG therapy and initiating rituximab, even more than a year later. Alterations in serum or CSF IL-6, soluble IL-2 receptor, and other cytokines were noted during the course of her clinicoradiographic relapses. Therefore, treatment was escalated to tocilizumab with sustained remission since its initiation in both patients. The third patient is earlier in his disease course and thus far responding well to monthly IVIG with plans to escalate to tocilizumab should he relapse. 

Conclusions:

Nonsyndromic relapsing TDLs are diagnostic conundrums that can cause significant neurological sequelae. Therefore, better characterization of these patients is critical to guide effective treatment.