Neurosarcoidosis-Induced Hypophysitis Mimicking Pituitary Macroadenoma.

Sarcoidosis is characterized by the presence of noncaseating granulomatous inflammation in the affected organs. Isolated involvement of the hypothalamic-pituitary axis in patients with sarcoidosis is rare. We report a rare case of a female patient in whom hypophysitis, mimicking a pituitary macroadenoma, resulted in pituitary transsphenoidal surgery. A female patient had been complaining of bilateral temporal headaches for over a month. Brain MRI showed a pituitary adenoma of height 16 mm, width 16 mm, and depth 12 mm. Hormonal assay showed central hypothyroidism and elevated level of prolactin. Histological examination revealed granulomatous hypophysitis. A specific search for Mycobacterium tuberculosis was negative on the pituitary tissue. After the exclusion of differential diagnoses, the combination of clinical, laboratory and radiological tests led to the diagnosis of neurosarcoidosis. This report presents an uncommon case of a pituitary localization of neurosarcoidosis mimicking a macroadenoma. Understanding the different MRI aspects of neurosarcoidosis is essential to avoid interpretive blunders that could result in an incorrect diagnosis.

Rituximab-induced mild encephalopathy with a reversible splenial lesion syndrome (MERS): An adverse effect to add to the list.

Mild encephalopathy with a reversible splenial lesion syndrome (MERS) is a rare clinico-radiological entity. Rituximab (RTX)-induced MERS has never been described before. Herein, we report the case of a 33-year-old patient diagnosed since 2017, with an IgG4-related disease (IgG4-RD). This diagnosis was retained in the face of a prolonged fever, sicca syndrome, hepatic damage and renal pseudotumour associated to a high level of IGg4 at 2.8 g/L with suggestive renal histology. The patient was treated with corticosteroid therapy with persistence of renal impairment and nephrotic syndrome indicating RTX therapy. The patient received his first dose of RTX and presented neurological and respiratory impairments a few hours afterwards. An infectious investigation comprising a SARS CoV-2 PCR and viral PCRs (VZV, herpes and CMV) on cerebrospinal fluid (CSF) were negative. The HBV, HCV, HIV, Parvo B19, CMV, EBV, herpes, mycoplasma and syphilis serologies as well as Legionella antigenuria were also negative. The patient had received intravenous immunoglobulins (IVIG) and methylprednisone, associated with sodium valproate with favourable outcome. The diagnosis of MERS induced by RTX was retained in our patient according to clinical and radiological features. We herein report the first case of MERS following RTX in a patient treated for IgG4-RD.