A spontaneous basal cell carcinoma with pulmonary metastasis in a 6-week-old SD rat.

To our knowledge, this is the first report on basal cell carcinoma with lung metastasis in a rat. A 6-week-old male Sprague-Dawley rat presented ulceration of the oral mucosa with surrounding tumor growth and white nodules in the lung. Microscopically, the mass showed solid, sheet-like growth with a partially lobular pattern and invaded the gingival mucosa, maxilla, and nasal submucosa.

Porencephaly in a cynomolgus monkey ( macaca fascicularis ).

Porencephaly was observed in a female cynomolgus monkey (Macaca fascicularis) aged 5 years and 7 months. The cerebral hemisphere exhibited diffuse brownish excavation with partial defects of the full thickness of the hemispheric wall, and it constituted open channels between the lateral ventricular system and arachnoid space. In addition, the bilateral occipital lobe was slightly atrophied.

Ectopic uterine ovarian tissue in cynomolgus monkeys.

Spontaneous ectopic uterine ovarian tissue was found in 9 of 118 cynomolgus monkeys (Macaca fascicularis), an incidence of 7.6%. These ectopic tissues were minute and were incidentally observed in the parametrium by microscopic examination.

Malignant myoepithelioma with a squamous epithelial component in the mammary gland of a cynomolgus monkey.

A solid mass arising from the mammary gland was found in a 7-year-old female cynomolgus monkey. Histologically, the mass consisted of 2 components: spindle-shaped or ovoid sarcomatous cells and squamous epithelial cells. Metastatic nodules noted in the lung, liver and the gallbladder had the same histological features as the mammary mass.