Primary mucinous adenocarcinoma of the eyelid

Primary mucinous adenocarcinoma (PMA) of the eyelid is an exceptionally rare clinical entity. Often, it mimics with benign lesions on clinical examination and with metastatic mucinous adenocarcinoma on histological examinations. We report a case of PMA in a 60-year-old male patient who came with a slow-growing, painless swelling near the lower lid of the left eye. Excisional biopsy from the mass revealed a mucinous adenocarcinoma. To differentiate it from a metastatic mucinous adenocarcinoma, a wide range of immunohistochemistry panel was run. The tumor cells showed strong positivity for cytokeratin7, cytokeratin5/6, p63, estrogen receptor, progesterone receptor and negativity for cytokeratin20. Moreover, extensive metastatic work-up did not show any primary malignancy elsewhere, hence a final diagnosis of PMA was made. We report a rare case of PMA from the Madinah region of Saudi Arabia.