MYOLIPOMA OF THE EYELID

Background: This report describes the pathology of a myolipoma which o ccurred in the eyelid. Myolipoma is a benign hamartomatous tumour in w hich smooth muscle cells are interspersed with adipocytes. Patient det ails: an irregular yellowish tumour (30x25 mm) with ill-defined border s had been present for 50 years in the medial part of the left lower e yelid of a 67-year-old woman. The tumour was excised and studied by co nventional histology, immunohistochemistry and transmission electron m icroscopy. Results: The tumour was formed by bundles of spindle-shaped cells with cigar-shaped nuclei intermingled with multiloculated clear cells containing small eccentric nuclei. By immunohistochemistry, pos itive staining of the spindle cells was restricted to smooth muscle ac tin and desmin; the clear cells were non-reactive with the immunohisto chemical panel, but fat was identified within the cytoplasm. The ultra structural features of the spindle cells were those of a leiomyoma, wh ile the clear cells were classified as adipocytes. Conclusion: This tu mour was considered to originate from the media of blood vessels withi n the tumour.