Patel, Naresh P.

ObjectiveIgG4‐related disease (IgG4RD) causing sinonasal and skull base pathology is uncommonly described. We present a series of suspected IgG4RD patients, with a pertinent review of the literature to highlight diagnostic challenges.Study DesignCase series.SettingAcademic tertiary care center.Subjects and MethodsCase series of patients with IgG4RD or suspected IgG4RD involving the sinonasal cavity and skull base.ResultsWe present 4 patients with atypical sinonasal and/or skull base disease who were noted to have IgG4‐positive plasma cell infiltration on immunohistochemistry of biopsy specimens. IgG4RD, a recently described entity affecting multiple organs, is characterized by lymphoplasmacytic infiltration and often elevated serum IgG4. IgG4RD can masquerade as malignancy or infection but responds to glucocorticosteroid and immunosuppressant therapy. IgG4RD has been infrequently reported presenting as sinonasal or skull base lesions, and definitive diagnostic criteria for these regions are not established. In our series, IgG4RD was suspected in all 4 patients, but only 1 met all current criteria for definitive diagnosis. All 4 patients, however, responded to corticosteroid therapy, and 1 was placed on long‐term azathioprine.ConclusionIgG4RD is rarely described in the sinonasal cavity and skull base, and specific diagnostic criteria for such disease have not been defined. We present a series of patients with IgG4‐positive plasma cell inflammatory pathology who were suspected to have IgG4RD. Our series highlights diagnostic challenges associated with these patients. Tumefactive and destructive sinonasal‐skull base lesions with a plasma cell‐rich infiltrate should incite suspicion of IgG4RD, and immunohistochemistry for IgG4‐positive plasma cells should be performed.

Objectives/HypothesisTo study reports of abducens nerve palsy following dural puncture procedures and to discuss possible etiologic theories, treatment, and prognosis.Study DesignSystematic review of peer‐reviewed literature.MethodsA systematic literature review was conducted (PubMed, 1950 to September 2011) for cases of sixth cranial nerve palsy following dural puncture procedures.ResultsWe report a case of abducens nerve palsy following lumbar drain placement for endoscopic trans‐sphenoidal pituitary macroadenoma resection. Sixth nerve palsy was noted immediately after surgery. Postoperative computed tomography and magnetic resonance imaging revealed no injury to the nerve or surrounding structures. A systematic literature review conducted for cases of abducens nerve palsy following dural puncture procedures found 22 studies (17 case reports and five case series). Twenty‐eight patients with temporary or permanent abducens nerve palsy were reported. Procedures included diagnostic lumbar puncture, spinal anesthesia, intrathecal catheterization, and shunting. Traction and local ischemia due to intracranial hypotension at the petroclival junction were proposed as causes of palsy.ConclusionsLumbar puncture procedures carry a rare risk of abducens nerve palsy from ischemic or traction injury. Routine use of lumbar drain during endoscopic skull base surgery is not without risk, and need for its placement should be carefully determined. Knowledge of such rare complications is helpful in risk–benefit analysis as endoscopic skull base techniques gain popularity.Level of Evidence4. Laryngoscope, 123:2633–2638, 2013

When coupled with classical clinical signs and symptoms, magnetic resonance imaging can significantly aid in the diagnosis of multiple sclerosis (MS). However, the differential diagnosis of multiple sclerosis is large and, in the absence of pathognomonic clinical features, can be challenging to diagnose initially. Some conditions, such as primary central nervous system lymphoma (PCNSL) and progressive multifocal leukoencephalopathy (PML), can mimic clinically some of the symptoms prominent in multiple sclerosis. Early treatment with corticosteroids can dramatically improve patient symptoms in MS and PCNSL. We report a case of a man diagnosed with histologically confirmed relapsing remitting multiple sclerosis who subsequently developed histologically confirmed primary central nervous system lymphoma. Immunosuppressant therapy in the treatment of multiple sclerosis may be a potential catalyst in the development of central nervous system lymphoma. The course of his disease and treatment are presented and the current literature reviewed.

Iatrogenic spinal arachnoid cysts are rare, but have been described as a complication of spinal injection and lumbar puncture procedures. The authors describe 2 cases of iatrogenic spinal arachnoid cyst formation that occurred after incidental durotomy during lumbar spine surgery. In both cases, postoperative MR imaging revealed compression of the cauda equina by an intradural arachnoid cyst. Intradural exploration and fenestration of the arachnoid cyst was accomplished in each case. This entity should be considered in the differential diagnosis of a patient experiencing symptoms of neurological compression after a lumbar surgery complicated by incidental durotomy.