Meningeal melanoma is more likely to develop from leptomeninges (pia, arachnoid) than the pachymeninges
Stable slightly prominent pachymeninges were found.
Table 1 Case Clinical presentation Initial diagnosis 1 Paravertebral mass Inflammatory myofibroblastic tumor 2 Parotid mass Idiopathic retroperitoneal Pachymeninges fibrosis Proptosis Inflammatory pseudotumor Non-Hodgkin's lymphoma 3 Lacrimal and salivary Mikulicz syndrome gland swelling 4 Recurrent pancreatitis Ampullary adenoma Case Treatment Serum IgG4 level 1 Oral cyclophosphamide 0.604 mg/dl (after treatment) 2 Mycophenolate mofetil Pretreatment level Steroid and rituximab is not available Steroid and rituximab 14.2 mg/dl after steroid Proton therapy treatment Pretreatment level is not available 3 Steroid and azathioprine 340 mg/dl Pretreatment level 4 Whipple's procedure 149 mg/dl Steroid and rituximab Pretreatment level
The characteristic findings in a brain MRI, present in approximately 70% of patients, are subdural fluid collections, enhancement of the pachymeninges
, engorgement of venous structures, pituitary hyperaemia and sagging of the brain (11).
The five characteristic imaging features of SIH visible on MRI are: (1) Subdural fluid collection and presence of extrathecal CSF (2) Enhancement of the pachymeninges
(3) Engorgement of venous structures (4) Pituitary hyperaemia and (5) Sagging of brain or downward displacement of brain.
Increased interstitial fluid of the pachymeninges
forms as a result of compensatory meningeal vasodilatation (1).