Normal squamous cells do not exist in the orbit. Therefore squamous cell carcinoma of the orbit is rare and usually arises as a secondary tumor from distant metastasis or local invasion. The authors herein describe the first case of primary squamous cell carcinoma of the orbit in Korea.

A 74-year-old female presented with a 2-month history of left upper eyelid swelling and ocular pain. On physical examination, a round, firm, fixed and tender mass was palpable in the superomedial side of the left orbit. Magnetic resonance imaging (MRI) showed 21 mm × 15 mm × 20 mm-sized irregular soft tissue mass with indistinct margin and peripheral enhancement in the superomedial portion of the left orbit, and incisional biopsy of the mass was performed. Histopathological examination showed clusters of squamous cells with polymorphic nuclei and interspersed keratin pearls, consistent with findings of well-differentiated squamous cell carcinoma. Despite extensive systemic work-up, there was no sign of extraorbital malignancy. The patient received left exenteration and adjuvant radiation therapy. Ten months after enucleation, a 12 mm × 14 mm sized firm mass developed on the left forehead, and excisional biopsy and frontalis rotational flap reconstruction were performed. Histopathological examination of the mass was consistent with well-differentiated squamous cell carcinoma. The patient remained alive 17 months after diagnosis without evidence of local recurrence or distant metastasis.

Primary squamous cell carcinoma should be considered in the differential diagnosis of acutely progressing tumors of the orbit.