JPC SYSTEMIC PATHOLOGY
SIGNALMENT (JPC #4087194): Female dog
HISTOPATHOLOGIC DESCRIPTION: Ovary: Arising from the ovarian surface epithelium, filling the ovarian bursa, and compressing periovarian adipose tissue is a non-encapsulated, well demarcated, 6x3mm, densely cellular neoplasm composed of neoplastic cuboidal to columnar epithelial cells arranged in single to multilayered cords and arborizing fronds supported on a fine to moderate fibrovascular stroma. Neoplastic cells have indistinct cell borders, a scant to moderate amount of eosinophilic fibrillar cytoplasm, a round to oval nucleus with finely stippled to clumped strands of chromatin, and 1-2 distinct nucleoli. Anisocytosis and anisokaryosis are moderate and mitotic count average 1 per ten 400x powered objective. Multifocally scattered throughout the neoplasm, there are few cysts that contain eosinophilic, proteinaceous material.
MORPHOLOGIC DIAGNOSIS: Ovary: Papillary carcinoma, Shih Tzu, canine.
SYNONYMS: papillary cystadenoma / cystadenocarcinoma;
- Ovary origin tumors include:
- Surface epithelium and SES
- Papillary and cystic adenomas
- Papillary adenocarcinomas
- Sex cord stromal tumors
- Granulosa cell tumors
- Thecoma, luteoma
- Germ cell tumors
- Gonadal stromal tumors (uncommon)
- Surface epithelium and SES
- Epithelium of the ovary includes:
- Lining (surface epithelium) of modified mesothelium
- Rete ovarii
- Subsurface epithelial structures (SES)
- Ovarian carcinomas occur in all domestic species but are more common in the bitch, are tumors that arise from the surface epithelium that covers the ovary
- Bitches: SES origin carcinomas are more common
- Metastasis to the oviduct or uterus is rare
- Tumor induction is reported in bitches by diethylstilbestrol administration
- May be associated with sex cord-stromal tumors
TYPICAL GROSS FINDINGS:
- Uni- to bilateral; cystic, multinodular enlargements
- Cut surface: exposes multiple cysts with yellow to brown fluid contents
- Cauliflower-like growths extending from the surface of the ovary with involvement
- Possible carcinomatosis if cyst rupture occurs, ascites if diaphragmatic lymphatic flow is obstructed
TYPICAL LIGHT MICROSCOPIC FINDINGS:
- Papillae lined by single to multiple layers of cuboidal to columnar cells on fibrovascular to connective tissue stalks
- May form single to multilayered cyst walls with lumen that contain proteinaceous material
- Carcinoma: larger size, areas of necrosis and hemorrhage, cellular atypia, neoplastic cell piling, increased mitotic count, stromal invasion
- Bursal and/or peritoneal invasion denotes malignancy
- Origin is determined by location of the largest mass if there are multiple sites
- SES express CK7 and Hector Battifora mesothelial epitope (HBME-1)
- Placental alkaline phosphatase expression (PLAP) in SES cells may be useful in differentiation of carcinomas of rete ovarii origin
- Sex cord-stromal tumors often express inhibin-α
- Carcinomas of the ovary: differentiated based on location
- Subepithelial surface structure origin carcinomas are located mostly in the ovarian cortex
- Rete ovarii origin carcinomas are most confined to the medulla adjacent to the ovarian hilus
- Subepithelial surface structure hyperplasia: may be concurrent with neoplasia
- Incidence increases with age
- Rarely extends inward beyond the primary follicles
- Multicentric whereas adenoma or carcinoma is focal
- Carcinoma originating in the oviduct or uterus: overall rare in domestic animals
- Other causes of enlarged ovary:
- Ovarian cysts
- Anovulatory follicles
- Uterine carcinomas: although rare occur more frequently in cattle
- Metastasis is frequent
- Histology: located deep in the endometrium with extension into the myometrium
- Adenomas are rare
- Agnew DW, MacLachlan NJ. Tumors of the genital system. In: Meuten DJ, ed. Tumors in Domestic Animals. 5th Ames, IA: John Wiley & Sons; 2017:690-694.
- Banco B, Antuofermo E, Borzacchiello G, Cossu-Rocca P, Grieco V. Canine ovarian tumors: an immunohistochemical study with HBME-1 antibody. J Vet Diagn Invest. 2011 Sep;23(5):977-981.
- Banco B, Ferrari R, Stefanello D, Groppetti D, Pecile A, Faverzani S, Longo M, Zani DD, Ravasio G, Caniatti M, Grieco V. Ovarian embryonal carcinoma in a dog. J Comp Pathol. 2017 Nov;157(4):291-295.
- Foster RA. Female reproductive system and mammae. In: Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier; 2017:1162.
- Schlafer DH, Foster RA. Female genital system. In: Maxie MG, ed. Jubb Kennedy and Palmer’s Pathology of Domestic Animals. Vol 3. 6th ed. Philadelphia, PA: Elsevier Saunders; 2016:375-377.