Spontaneous Basal Cell Carcinoma in a 7-Week-Old Sprague-Dawley Rat

Abstract

Spontaneous basal cell carcinoma (BCC) is very rare in rats, with an incidence rate of only 0.14% reported in aged animals. A spontaneous BCC occurred in a 7-week-old Sprague-Dawley rat housed in a specific-pathogen-free animal facility. The tumor was a single, well-delineated reddish-brown subcutaneous mass measuring 2 x 2 cm and located in the left inguinal region. Microscopically, the tumor consisted of basaloid cells in lobular and cribriform growth patterns and with a high mitotic rate. Immunohistochemically, cytokeratin 14 (an indicator for basal keratinocytes of the epidermis) showed strong reactions throughout the whole tumor, and cytokeratin 18 showed weak but positive reaction in the majority of nested tumor cells. To the authors' knowledge, this is the first report of spontaneous BCC occurrence in young Sprague-Dawley rats.

A 13-Week Repeated Oral Dose Toxicity Study of ChondroT in Sprague-Dawley Rats

“…It is also rarely observed in young SD rats. Spontaneous basal cell carcinoma was reported recently in a subcutaneous mass found in the left inguinal region of a young (7-week) SD rat [21, 22]. In the present study, this lesion was only observed in one animal in the middle dose group and did not result in a dose-dependent response.…”

Spontaneously occurring multicentric basal cell carcinoma and keratoacanthomas in a multimammate mouse (Mastomysspp.)

“…The tumor was solitary and likewise showed a strong positivity for CK14 antigen. 13 Basal cell carcinomas have also been induced experimentally in M. natalensis and mice by application of 7,12-dimethylbenz(a)anthracene (DMBA) and 12-0-tetradecanoyl-phorbol-13-acetate (TPA) and other mutagenic chemicals. 14,27 Squamous cell carcinomas have been induced by the same 2-stage skin carcinogenesis (DMBA+TPA) in transgenic mice that carried an oncogene of MnPV.…”

“…2,3,5,10 The malignant form, basal cell carcinoma (BCC), has a very low incidence of spontaneous occurrence in laboratory rats and mice (0.14% and 0.1%, respectively). 13,17 In domestic animals, BCC is described in cats most frequently. In other domestic animals, BCCs are rare or have not been described.…”

树鼩(Tupaia belangeri chinensis)基底细胞癌模型的建立

“…Most are transgenic mouse models, such as Ptch1 knockout mice ( Arad et al, 2008 ; Aszterbaum et al, 1999 ; Nitzki et al, 2010 ; Skvara et al, 2011 ; So et al, 2004 ), or include constitutive activation of other Hh signaling pathway key regulators, such as oncogenic Smo , Gli1 , or Gli2 mutation expressions driven by skin-specific keratin (K) 5, 6, or 14 promoters (Nitzki et al, 2012). In seven-week-old Sprague-Dawley rats, e.g., spontaneous BCC tumors were observed as single, reddish-brown subcutaneous masses located at the left inguinal region, basaloid cells showed lobular and cribriform growth with high mitotic rates, and cytokeratin 14 and cytokeratin 18 were expressed in nest tumor cells, thereby indicating that spontaneous BCC can occur in young rats ( Lee et al, 2010 ). Nano-electro-ablation methods have been found to induce apoptosis efficiently in a Ptch1 (+/-) K14-Cre-ER p53 fl/fl mouse BCC model ( Nuccitelli et al, 2012 ).…”