sebaceous lymphadenoma sebaceous lymphadenoma sebaceous lymphadenoma is a benign tumour of the salivary gland. sebaceous lymphadenomahigh magnification micrograph of a sebaceous lymphadenoma. h&e stain.specialtyent surgery diagnosis sebaceous lymphadenoma is a tissue diagnosis, e.g. salivary gland biopsy. it may be confused with a number of benign and malignant neoplasms, including warthin tumour, mucoepidermoid carcinoma and sebaceous lymphadenocarcinoma. treatment the treatment is simple excision and exclusion of a malignant neoplasm.