Gender: Female Intact
Five year swelling of lower right eyelid. FNA; very bloody aspirate.
Image 1: Cytology 20X
Image 2: Cytology 50X
Image 3: Cytology 100X
Image 4: Histopathology overview; low power.Click here for the IDEXX Pathology Report on this case.
One slide is received and evaluated. It is highly cellular and consists of variably sized cohesive clusters of epithelial cells in a thick peripheral blood background with associated leukocytes and platelet clumps and moderate numbers of bare nuclei. Epithelial cells are round to polygonal with relatively indistinct cytoplasmic borders. Nuclei are round to slightly oval with smooth chromatin and no visible nucleoli. Cytoplasm is moderately abundant and has a foamy/vacuolated appearance. Significant atypia is not appreciated. No infectious organisms are seen.
This lesion exfoliated well and tissue cells are epithelial in origin. They are foamy/vacuolated indicating glandular origin and given the location a lacrimal gland adenoma is considered most likely. Biopsy with histopathology would be required to obtain a final diagnosis.
Additional history received with excised tissue submitted for biopsy: Extensive mass involving 360 degrees around right eye; right globe enucleated.
Histopathology: Neoplastic cells were observed in a portion of haired skin that were positive for Periodic acid Schiff (mucinous intracytoplasmic granules) consistent with canine lobular orbital adenoma. Neoplastic cells were not observed in the eye or optic nerve.
Canine lobular orbital adenomas are benign glandular tumors that can rarely occur bilaterally. They are lobulated, friable and often contain PAS-positive secretory mucin. Clean margins can be difficult to obtain and recurrences do occur. The specific gland has not been identified, but small accessory lacrimal tissues are thought to be the tissue of origin. These tumors lack duct formation which differentiates them from lacrimal adenomas, salivary adenomas, adenocarcinomas and pleomorphic lacrimal adenomas.
Dubielzig RR, Tumors of the Eye. In Meuten DJ, ed. Tumors in Domestic Animals. 5th ed. John Wiley & Sons, Inc.: 918, 920.
Schappa JT, Peterson A, Dubielzig RR, et al. What is your diagnosis? Upper eyelid swelling in a dog. Vet Clin Path 2014; vol. 43 issue 1; 111-112.