Sebaceous carcinoma: clinicopathologic features and diagnostic role of immunohistochemistry (including androgen receptor).

OBJECTIVE

To explicate the clinicopathologic features of periocular sebaceous carcinoma (SC) and emphasize the importance of immunohistochemical staining that includes androgen receptor (AR) in their diagnosis.

DESIGN

Retrospective study.

METHODS

Clinical and histopathologic features in 56 patients with periocular SC were analyzed. Immunohistochemical staining for pan-cytokeratin (CK), epithelial membrane antigen (EMA), Ber-EP4, adipophilin (ADP), and AR was performed on all cases. Immunostaining in SC was compared with that of squamous cell carcinoma (SCC; n = 25) and basal cell carcinoma (BCC; n = 18) for all antibodies.

RESULTS

SGC was more frequent in females, most commonly presenting as a discrete and nodular mass. Four patients had regional lymph node metastases, whereas in 2, the tumour metastasized to the liver. Eight patients had a locoregional recurrence between the 3rd and 45th months of follow-up. Fifty patients had a moderately differentiated tumour. In 3 patients, the resected margins displayed intraepithelial tumour spread, and 2 patients died of the disease. In general, the staining pattern in SGC was CK(+), EMA(+), BerEP4(-), ADP(+), and AR(+). SCCs were CK(+), EMA(+), Ber-EP4(-), ADP(-/+), and AR(-), whereas BCC were CK(+), EMA(-), Ber-EP4(+), ADP(-), and AR(-/+). p53 expression and Ki-67 index were higher in SC than SCC or BCC.

CONCLUSIONS

Immunostaining using a panel of antibodies comprising BerEP4, ADP, EMA, and AR is useful in diagnosing sebaceous carcinoma and differentiating it from SCC and BCC, which are common to the periocular location and sometimes are morphologically identical to SC.