Clinical appearance of a spiradenoma in primary (A and B) and secondary tumors (C and D). A. A round to oval-shaped nodule with smooth borders was present in the right upper palpebral conjunctiva. B. The tumor cells were arranged in intertwining bands just beneath the conjunctiva. Two types of neoplastic cells were recognized; one had a small dark nucleus representing an undifferentiated cell, and the other was located at the center of the bands with large pale nucleus. Levels of mitotic counts were low (0.3/10 HPF). Hematoxylin-eosin staining. C. The tumors can be seen on the right upper palpebral conjunctiva, which was the slightly upper location of the previous tumor. Its surface is smooth. D. A solid and well-circumscribed nodule can be seen beneath the conjunctival epithelium. It is composed of cells with slightly basophilic-to-clear cytoplasms and round-to-oval nuclei and arranged in a trabecular pattern. Mitotic activity was increased (5.5/10 HPF) throughout the tumor with no necrosis. Hematoxylin-eosin staining.