Dacryops with extensive lacrimal and maxillary bone defects in four dogs

To describe and discuss ventromedial orbital lacrimal gland or duct cysts (dacryops) in dogs with extensive bone defects based on their symptoms, results of diagnostic imaging and histopathological examination, and therapy and discuss their potential origin based on the morphology.

Four dogs of different breeds, age, and sex were presented with a unilateral round, slow growing, indolent, and non-tender process ventromedial to the nasal canthus of the eye.

Transverse computed tomography showed a low-density, non-contrast-enhancing cystic process ventromedial to the globe with extensive defects in the lacrimal and maxillary bones in all cases. The cystic character of the structure was confirmed by the aspiration of the brownish fluid without cellular and microbiological contents. For treatment, the cystic fluid was aspirated, and the sclerosing agent polidocanol was injected in three cases. Cystorhinostomy (nasal marsupialisation) was performed in one case as the first choice and in another case following failure of sclerotherapy. Histopathological examination of the cyst walls was performed in two cases and confirmed the diagnosis of dacryops.

Follow-up between 2 and 18 months showed no recurrence and very good to excellent cosmetic results.

Aberrant lacrimal gland or duct tissue with secondary development of dacryops should be included in the differential diagnoses of ventromedial orbital cysts. Large cysts near the lacrimal drainage system with extensive bone defects in dogs should be treated by nasal marsupialization. Treatments such as evacuation of the cyst and inducing sclerosis (sclerotherapy) should be reserved for exceptional cases.