Luteinizing follicular cyst in a dog

History: Tissue from an 11 month old female Great Dane.  The tissue was removed during a routine spay surgery and submitted for histopath due to abnormal appearance.

Ovary: Large corpus luteum at the top of the image and a smaller luteinizing follicle in the center

Ovary: Below the solid corpus luteum is a large cyst lined by granulosa cells with a focal area of luteinization (foamy vacuolated cells)

Ovary: Higher magnification of the luteinizing cells lining the cyst

Ovary:  In each section examined there are primary follicles present in a fibrovascular stroma.  There are two normal corpora lutea present consisting of a large solid mass ofpolygonal cells with large intracytoplasmic lipid vacuoles (luteinized cells). In addition there are two large cystic follicles partially lined by luteinized cells and partially lined by follicular epithelium.

Comment:

Luteinized ovarian cysts are derived from anovulatory Graffian follicles and can cause hyperestrogenemia in some cases and are associated with cystic endometrial hyperplasia and development of pyometra in dogs.

Tissue from an 11 month old female Great Dane was submitted for histopathology.  During the spay

surgery the submitting veterinarian noticed an abnormal anatomical arrangement of the reproductive

tract and requests identification of the submitted tissue to see if it is ovarian or lymphoid.