Diagnostic Considerations
Sarcoidosis in general can at times be notoriously difficult to diagnose. A delay in diagnosis can result in increased morbidity and, in rare occasions, death. Patients who develop a neurologic illness consistent with neurosarcoidosis but are not known to have sarcoidosis present a diagnostic challenge. Other causes of neuropathy need to be considered, depending on the type of neuropathy, including acquired causes such as toxin exposure, metabolic abnormalities, and inflammatory disorders.
Neurosarcoidosis should not be readily diagnosed in children. This disorder is not common in children, and care must be taken to exclude other pathologies before this diagnosis is made.
Although necrotizing sarcoidosis has been reported most commonly in the lungs and rarely in other organ systems, sarcoidosis and its necrotizing variant should be considered in the differential diagnosis of an agranulomatous mass lesion involving the CNS. This is particularly true in patients with a history of systemic disease.
Other problems to be considered in the differential diagnosis of neurosarcoidosis, depending on the presentation, include the following:
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Brain tumors
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Porphyria
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Toxins such as alcohol and drugs (both therapeutic and recreational)
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Neuropathies associated with monoclonal bands and paraproteinemias
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Myopathy of all types
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Carcinomatous and lymphomatous meningitis with resultant polyradiculopathy
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Berylliosis
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Vitamin B-12 deficiency
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Paraneoplastic neuropathy
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Paraproteinemic neuropathy
Differential Diagnoses
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Otolaryngologic Manifestations of Granulomatosis With Polyangiitis
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Pediatric Lyme Disease
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Atrophic right optic disc of a 37-year-old man with neurosarcoidosis and involvement of both optic nerves. Vision was lost. The disc is pale with sharp borders.
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Atrophic left optic disc of a 37-year-old patient with neurosarcoidosis and involvement of both optic nerves. The disc is pale with sharp borders. Vision was largely preserved.
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MRI of the brain in a 37-year-old man with neurosarcoidosis who had complete loss of vision in the right eye for 2 months and occasional blurry vision in the left. T1-weighted sagittal image shows intact optic nerves.
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MRI of the brain in a 37-year-old man with neurosarcoidosis who had complete loss of vision in the right eye and mild left eye blurriness. This fluid-attenuated inversion recovery (FLAIR) axial image shows a wedge-shaped area of infarction in the right temporo-occipital area. The optic nerves exhibit abnormal signal.
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MRI of the brain in a 37-year-old patient with sarcoidosis who had right eye blindness and mild blurry vision in the left eye. This postgadolinium, T1-weighted axial image shows right optic nerve enhancement along almost the entire intraorbital portion and a small amount in the prechiasmatic portion. The left optic nerve enhances from the level of the optic chiasm to the distal intraorbital portion. The right temporo-occipital infarct is seen as a faint hypodensity; it does not enhance after gadolinium administration.
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MRI of the brain in a 37-year-old man with sarcoidosis who had loss of vision in the right eye and blurry vision in the left eye. This scan was taken 6 months after the scan shown in Pictures 3, 4, and 5. Both the right and left optic nerves are enlarged and show abnormal signal on this T1-weighted axial image. The patient remained on oral prednisone from the time of the first scan and did not exhibit any further loss of vision in the left eye. Vision in the right eye never returned.
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MRI of the brain in a 37-year-old man with sarcoidosis who had loss of vision in the right eye and blurry vision in the left. This postgadolinium, T1-weighted axial image shows abnormal enhancement of both optic nerves, with the left optic nerve appearing worse on this study than in the study shown as Picture 5, which was done 6 months earlier. The right temporo-occipital hypodensity represents the old infarction.
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Early chest radiograph findings in sarcoidosis.
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Advanced chest radiograph findings in sarcoidosis.
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Noncaseating granuloma surrounded by epithelioid cells, from the medulla oblongata. Also shown are nodular inflammatory infiltrates consisting of multinucleated giant cells, macrophages, and lymphocytes (hematoxylin and eosin, 40x).
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Noncaseating granuloma in medulla oblongata showing the granuloma surrounded by epithelioid cells and nodular inflammatory infiltrates (hematoxylin and eosin, 20x).
