Fig. 55. Papillary squamous cell carcinoma of lacrimal sac. A. Patient has squamous cell carcinoma of the right lacrimal sac. B. Another patient shows frank invasion present at base. C. High magnification shows nests of squamous cell carcinoma invading subepithelial tissue. (A, courtesy of Dr. A. B. Spaulding and presented at the 1982 Verhoeff Society meeting; B and C, from Ryan SJ, Font RL: Primary epithelial neoplasms of the lacrimal sac. Am J Ophthalmol 76:73, 1973.)