Myolipoma of the eyelid

This report describes the pathology of a myolipoma which occurred in the eyelid. Myolipoma is a benign hamartomatous tumour in which smooth muscle cells are interspersed with adipocytes. PATIENT DETAILS: An irregular yellowish tumour (30 x 25 mm) with illdefined borders had been present for 50 years in the medial part of the left lower eyelid of a 67-year-old woman. The tumour was excised and studied by conventional histology, immunohistochemistry and transmission electron microscopy.

The tumour was formed by bundles of spindle-shaped cells with cigarshaped nuclei intermingled with multiloculated clear cells containing small eccentric nuclei. By immunohistochemistry, positive staining of the spindle cells was restricted to smooth muscle actin and desmin; the clear cells were non-reactive with the immunohistochemical panel, but fat was identified within the cytoplasm. The ultrastructural features of the spindle cells were those of a leiomyoma, while the clear cells were classified as adipocytes.

This tumour was considered to originate from the media of blood vessels within the tumour.