RESUMO
Syringomyelia is a fluid-filled cyst within the spinal cord and is usually associated with conditions that obstruct the cerebrospinal fluid (CSF) (flow at the foramen magnum or spinal levels such as Chiari malformations, arachnoiditis, and basilar invaginations). Very rarely, posterior cranial fossa tumors can lead to tonsillar herniation and secondary syringomyelia. There are only nine reported cases in the literature. We report a rare case of a 56-year-old female with posterior cranial meningioma and secondary syringomyelia, admitted with headache, nausea, vomiting, and ataxic gait. Magnetic resonance imaging (MRI) demonstrated a large posterior fossa lesion causing early ventriculomegaly and a giant cervicothoracic syrinx within the upper spinal cord extending from the hindbrain inferiorly to the level of T8. She underwent a posterior fossa craniectomy with left C1 hemilaminectomy and complete excision of the tumor. In 6 months following her procedure, an MRI scan showed a significant reduction in the caliber of the syringomyelia throughout its length, and there was a significant improvement in symptoms. Although the pathophysiology of syrinx formation is still poorly understood, the alteration of CSF dynamic flow has been implicated. A common unifying cause appears to be increased transcranial difference in intracranial pressure across the foramen magnum causing tonsillar herniation, irrespective of location in the posterior fossa. With high syrinx pressure, mechanical stress-induced structural change of the spinal cord occurs, allowing the persistence and progression of the syrinx in the spinal cord. Syringomyelia appears to be resolved partially or completely after craniotomy and excision of the posterior fossa lesion.
RESUMO
BACKGROUND: Pituitary dysfunction (PD) in granulomatosis with polyangiitis (GPA) is a rare manifestation of the disease with an incidence of 2% and tends to occur as the disease progresses. On very rare occasions, PD can be the initial presentation of GPA. From our literature review, only 6 such cases were documented. CASE PRESENTATION: We present a rare case of GPA in a 57-year-old female who primarily presented with PD and visual disturbance without any other systemic features of GPA. Her initial ANCA screen was negative and her MRI scan showed an enlarged pituitary gland with cystic changes. A pituitary biopsy confirmed the diagnosis and she was started on immunosuppressants. After completing her immunotherapy, her diabetic insipidus subsided and her vision markedly improved. LITERATURE REVIEW: A literature search on Pubmed, Cochrane, Open Grey, and SciELO with keywords 'granulomatosis', 'polyangiitis', and 'pituitary' was performed. A total of 72 articles were reviewed. 6 articles were identified where PD was the presenting complaint of GPA without other systemic involvement. DISCUSSION: Secondary hypophysitis in GPA indicates pituitary inflammation resulting from systemic disease or pituitary near-lying lesions. PD in GPA tends to occur with concomitant active disease at other sites. Headache seemed to be a common presenting feature with diabetic insipidus being the most common type of PD. Tissue biopsy is essential to confirm diagnosis. Pituitary biopsy is rarely required as other organ involvement is available for safer tissue sampling. However, in our case, pituitary biopsy had a role in confirming diagnosis and avoiding treatment delay. CONCLUSION: PD as a primary manifestation in GPA without systemic involvement is very rare and poses a diagnostic challenge. Pituitary biopsy can aid in diagnosis, allowing prompt treatment and prevention of long-term complications of untreated GPA such as permanent pituitary dysfunction. Nevertheless, the risk and benefit of pituitary surgery in each case should be weighted.
