Ali MJ, et al. - Researchers examined the ultrastructural features of the mucopeptide concretions obtained from the lacrimal sac. They immediately fixed mucopeptide concretions obtained from the lacrimal sacs of 10 patients during a dacryocystorhinostomy for electron microscopic analysis. Based on their extent, mucopeptide concretions take the shape of the lacrimal sac and nasolacrimal duct. Observation revealed mostly areas of homogenous deposits with occasional intervening heterogenic areas while analyzing the external surfaces and cut sections. They noted 2 distinct types of craters, mostly in the heterogeneous areas. Extensive networks of fibril-like tangles filled predominantly with granular material and red blood cells with occasional presence of granulocytes and epithelial cells made the core of the concretions. They suggest assessing ultrastructural features of mucopeptide concretions from the lacrimal sac to gain better understanding their etiopathogenesis and tissue interactions.