Chariyabhorn Khamjai, M.D. Department of Anatomical Pathology, Maharat Nakhonratchasima Hospital, Nakhornratchasima 30000, Thailand E-mail: email@example.com Tumtip Sangruchi, M.D. Department of Pathology, Faculty of Medicine Siriraj Hospital, Mahidol University 2 Prannok Rd. Bangkok 10700,Thailand E-mail: firstname.lastname@example.org Tel. + 66 -02- 4196504 FAX + 66 -02- 4114260
The purpose of this study is to describe histopathological ﬁ ndings of frontoethmoidal meningoencephalocele (FEEM), and to correlate with the embryogenesis. The study materials were gathered from 86 cases of FEEM, during 1995-2005. The histopathology was observed in terms of the pattern of the lesion, the relation to the skin and surrounding soft tissue, and the differentiation of cell components. The histopathology was described as solid, disperse and reticular patterns of mature neuroepithelium and meningothelial tissue with varying amount of ﬁ brosis. The lesions occupied the dermis, subcutaneous fat and facial muscle. The dermal-epidermal junction was not involved. Regarding histopathology and embryogenesis, misplaced primitive neuroepithelium in the early embryonic stage before development of the epidermis, muscle and bone are the proposed pathogenesis from this study mechanism for developing such lesion.