January 2019

Signalment (JPC# 997552):  Rabbit


HISTOPATHOLOGIC DESCRIPTION:  Uterus:  Multifocally and transmurally infiltrating and effacing the uterus is an unencapsulated, densely cellular, poorly demarcated neoplasm composed of polygonal cells arranged in tubules, acini, and solidly cellular areas on a variably dense collagenous to myxomatous matrix (desmoplasia).  Neoplastic cells have indistinct cell borders, a small amount of eosinophilic cytoplasm, a round to oval nucleus with finely stippled chromatin, and indistinct nucleoli.  There is mild anisocytosis and anisokaryosis, and less than one mitotic figure per ten 40x HPF.  Tubules are ectatic with fronds of neoplastic cell bulging into the lumen, and are often filled with eosinophilic proteinaceous and/or mucinous material admixed with variable amounts of necrotic cellular debris.  Multifocally, there are neoplastic cells within uterine lymphatic vessels.  There are multifocal areas of coagulative necrosis with loss of differential staining and retention of architecture, as well as multifocal areas of lytic necrosis, characterized by loss of tissue architecture and replacement by eosinophilic cellular and karyorrhectic debris admixed with low numbers of lymphocytes, heterophils, and hemorrhage.  Within several cross sections of the uterus, the endometrium is hyperplastic forming papillary projections often lined by epithelium that piles up two to three layers thick.  Multifocally hyperplastic glands are markedly ectatic forming cystic structures and are lined by attenuated epithelium (cystic endometrial hyperplasia).


  1. Uterus: Adenocarcinoma, breed unspecified rabbit, lagomorph.
  2. Uterus, endometrium: Hyperplasia, cystic, diffuse, moderate.







Other causes of uterine enlargement:



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