A combination of factors as the
meningioma's rich vascularity, its low metabolic rate,
immunologic factors and the molecular pattern explains the affinity of some
cancer metastasis to seed inside
meningiomas. In this context, the importance of surface adhesion molecules is of rising interest.
CASE REPORT: We report the exceptional case of a parotid
carcinoma metastasis within a
meningioma. A 68-year old male was referred to our hospital with
headache and progressive right
hemiparesis. Four years before he was diagnosed with parotid gland
cancer for which he had undergone parotidectomy, radiation,
neck dissection and
chemotherapy. MRI showed a left sided high-parietal, dural-based, extraaxial, contrast enhancing
tumor which was consequently removed microsurgically. Histological examination revealed a dedifferentiated parotid
carcinoma metastasis inside a
microcystic meningioma WHO grade I. Mechanisms that have been suggested to be responsible for
metastasis into
meningioma include
meningiomas' rich vascularity, slow growth, their high
collagen and
lipid content,
immunologic factors but also the expression of certain surface adhesion molecules, in particular
E-cadherin. In the presented case
E-cadherin immunostaining was strongly positive in the metastatic tissue that invaded the
meningioma in a droppled-like fashion. We discuss the potential role of
E-cadherin, re-expression of a modified
E-cadherin complex and the potential importance of mesenchymal
surface proteins in the pathophysiology of
carcinoma metastasis into
meningioma.
CONCLUSION: