Abstract
Background: Although sebaceous carcinoma, eccrine mucin-producing sweat gland carcinoma/mucinous carcinoma, hidradenoma, and syringoma are mostly common in the eyelid, other cutaneous adnexal tumors are rare.
Case presentation: An 88-year-old female presented with a yellow-whitish nodule in the left upper eyelid. Histopathology revealed basaloid tumor cells with an infiltrative growth pattern. The tumor cells exhibited sebaceous differentiation in the superficial part but also ductoglandular formation in the deep part. Immunohistochemically, the tumor cells were positive for SOX10, S100 protein, BerEP4, and c-kit, but negative for p63, androgen receptor, SMA, chromogranin A, and synaptophysin. In the superficial part with sebaceous differentiation, sebocyte-like tumor cells showed cytoplasmic staining of adipophilin, PRAME, and STAT6.
Conclusion: This tumor harbored a morphological and immunohistochemical phenotype of sweat gland differentiation and sebaceous differentiation, which does not fit any established tumor entities. This challenging eyelid tumor may be misdiagnosed as sebaceous carcinoma, in which caution should be exercised.