Primary clear cell meningioma of the orbit mimicking a metastatic carcinoma: usefulness of immunohistochemistry and cytogenetic analysis

Abstract

Clear cell meningiomas (CCM) are rare tumors of the nervous system that usually occur in young patients and display high recurrence rates and potentially aggressive behavior. In this report, we describe a primary CCM of the orbit in an 84-year-old man with a previous history of a clear cell carcinoma of the kidney. Histologically, the tumor demonstrated a sheet-like proliferation of clear polygonal cells. Differential diagnosis includes metastasis of clear cell carcinomas. Immunohistochemistry, by showing that tumor cells expressed vimentin, epithelial membrane antigen, and progesterone antigens, and cytogenetic analysis, by identifying a monosomy 22, confirmed the diagnosis of CCM.

Loss of SMARCE1 expression is a specific diagnostic marker of clear cell meningioma: a comprehensive immunophenotypical and molecular analysis

“…This is consistent with the low mean (30.9 years) and median (26 years) age of patients with CCM (from 8 months to 88 years) relative to the median age of meningioma in general (65 years) . In the literature, the female‐to‐male ratio of patients with CCM was 1.1 (124 females and 110 males) (, cf. review in ).…”

“…The most common are germline NF2 mutations, responsible for neurofibromatosis type 2 (NF2) . Two genes ( SMARCB1 and SMARCE1 ), encoding two proteins of the SWI/SNF complex (BAF47 and SMARCE1), have also been recently implicated in hereditary meningiomatosis (, cf. review in ).…”