[A rare parotid tumor]

Sebaceous lymphadenoma of the parotid (SLP) is a rare, benign tumor with similar epidemiological and macroscopic characteristics with other sebaceous differentiated tumors of the parotid (SDTP). The authors report a case of SLP in an 80-year-old woman. They then recall the distinctive histological and immunohistochemical criteria of SDTP.

Mrs P. D. was received during a surgical consultation for the management of a painless right parotid swelling that has evolved for 10years, increasing slightly in volume. At admission, the mass was movable, firm with a healthy skin without facial paralysis or satellite lymphadenopathy. The surgical intervention performed removed a nodular mass measuring 7cm, encapsulated, yellowish. It was made of regular epithelial cells without atypia or mitoses organized in nests, trabeculae and massifs. This tumor also included small canalicular cystic dilatations associated with several islands of sebaceous glands. The stroma was dense lymphoid with follicles and germinal centers. The tumor cells were CK7+, P63+, MSA+ and had a Ki67<5%. The diagnosis of an SLP was retained. No additional therapy was performed. One year after surgery, the patient had no local recurrence or metastatic foci.

SLP is a rare tumor with a particular histological and immunohistochemical profile. It is an epithelial tumor with sebaceous islands, a dense reactional lymphoid stroma, expression of luminal and basal epithelial markers and a low proliferation index.