Papillomas, squamous cell

In another smdy, skin tumors, including papillomas, squamous cell carcinomas, and malignant melanomas, were seen in mice receiving skin applications of 21% or 86.5% EHA in 2 5 pi of acetone three times per week for 2 years. ... 

Squamous Squamous cell papilloma Squamous cell carcinoma... 

Chronic 8-MOP administration of up to 75 mg kg for 2 years increases the incidence of renal tubular cell hyperplasia, adenomas, and adenocarcinomas of the kidney and carcinomas of the zymbal gland in male rats. 8-MOP with the addition of UVA induces the development of squamous cell hyperplasia, squamous cell papilloma, squamous cell carcinoma, cutaneous melanoma, and cataracts in rats. 

Rabbit (Australian albino) 15 wk 3 x/wk 10 M Percent (%) (CEL papillomas, squamous cell carcinoma,s keratoacanthomas cutaneous horns) Kligman and Kligman 1994 coal tar... 

Crude coal tar (10, 25, and 100%) in petrolatum was applied to the ear of male Australian albino rabbits (3 per group) 3 times/week for 15 weeks (Kligman and Kligman 1994). Crude coal tar was both comedogenic and carcinogenic at all doses tested (10, 25, or 100%). Tumors developed as early as 1-2 weeks after 3 weeks of treatment with 10% coal tar. The tumors were classified as papillomas, squamous cell carcinomas, keratoacanthomas, and cutaneous horns, and became extremely numerous with longer treatment. 

Fig. 13.9 Double immunostaining of squamous cell metaplasia for K14 (green) an K10 (red) in a papilloma of the breast...

No skin cancer was reported in B6C3Fj mice chronically exposed to 250 and 500 mg/kg/day of JP-5 (NTP/NIH 1986). There was a 2-6% incidence of squamous cell papilloma and/or carcinoma of the skin in B6C3Fj mice chronically exposed to 250 (females only) or 500 (both sexes) mg/kg/day marine diesel fuel. The effect did not occur in the control groups the statistical significance of these effects was not reported. Hepatocellular adenoma or carcinoma were noted in males exposed to 250 and 500 mg/kg/day... 

J,l/mouse, twice a week for 25 weeks, to female ICR mice produced forestomach tumors (squamous cell carcinoma and papilloma), lung tumors (adenocarcinoma and adenoma), and tumors of the hematopoietic system (thymic lymphosarcoma and lymphatic leukemia), with dose-related response by 18 months. It was concluded that the target organ of benzotrichloride carcinogenesis in mice is the local tissue that is primarily exposed and the lung and hematopoietic tissue when administered systemically. 

In a lifetime dermal oncogenesis study in mice, 20 mg EHA in acetone was applied 3 times weekly for their lifespan. There were 40 mice in the group at the start of the study. Two animals developed squamous cell carcinomas, and four other animals had squamous cell papillomas. The first tumor was observed after 11 months of treatment. None of the acetone-treated controls developed tumors. There was an apparent increase in the frequency of chronic nephritis in the EHA-treated mice (68% compared with 15% in controls). Treatment with EHA may have exacerbated the onset and development of this condition, which is normally seen in aged mice. 

In a long-term bioassay, styrene oxide administered to rats by gavage (250 or 50mg/kg daily for 1 year) produced a high incidence of tumors in the forestomach (papillomas, acanthomas, and in situ and invasive squamous cell carcinomas)/ Styrene oxide also increased the incidence of squamous cell papillomas and carcinomas of the forestomach in mice when administered by gavage at doses of 375 or 750mg/kg for 2 years/... 

Administration of VCH by oral intubation to rats 5 days/week for 2 years at 0, 200, or 400mg/kg/day was associated with slightly increased incidence of epithelial hyperplasia of the forestomach and squamous cell papillomas or carcinomas of the skin in high-dose males. Poor survival of the dosed animals may have compromised the study. In mice similarly dosed, the number of uncommon ovarian neo-... 

Two-year studies were conducted by administering VCD in acetone by dermal application 5 days per week for over 100 weeks to groups of rats of each sex at 0, 15, or 30mg/animal and to groups of mice at 0, 2.5, 5, or lOmg/animal. Acanthosis and sebaceous gland hypertrophy of skin from the scapula were observed at increased incidences in both species. Squamous cell papillomas in male rats and squamous cell carcinomas in males and females were observed in exposed rats at an increased incidence. The combined incidence of basal cell adenomas or carcinomas was also increased in both sexes. Squamous cell carcinomas were found in the exposed mice. Follicular atrophy and tubular hyperplasia of the... 

From National Toxicology Program (1993) Flepatocellular adenomas Squamous-cell papillomas and carcinomas p <0.05, logistic regression test p < 0.01, logistic regression test... 

Squamous-cell papillomas or carcinomas and sebaceous gland adenomas Squamous-cell papillomas and carcinomas Elepatocellular adenomas Alveolar/bronchiolar adenomas p < 0.05 Fisher s exact test p< 0.01 Fisher s exact test... 

Squamous-cell papillomas or carcinomas, basal-cell tumours, sebaceous adenomas, keratoacanthomas Squamous-cell papillomas or carcinomas Squamous-cell papillomas Adenocarcinomas Adenomatous polyps Adenomas... 

Adenomas and adenocarcinomas Squamous-cell papillomas Hepatocellular adenomas and carcinomas Adenocarcinomas... 

Adenomas and carcinomas Squamous-cell papillomas and carcinomas Leukaemia... 

D,L-Diepoxybutane and /wcAso-diepoxybutanc induced skin papillomas and squamous-cell carcinomas when applied to the skin of female Swiss mice at a dose of approximately 3 or 10 mg in 100 mg acetone three times per week for life (Van Duuren et al., 1963, 1965). Subcutaneous injection of 0.1 mg D,L-diepoxybutane in 0.05 mL tricaprylin once per week for more than one year induced local fibrosarcomas in female Swiss mice no tumour was observed in three solvent-treated control groups. Similar findings were seen in female Sprague-Dawley rats (Van Duuren et al., 1966). 

Groups of 10-20 male Fischer 344 rats, seven weeks of age, received catechol (> 99.8% pure) in the diet at concentrations of 0 or 1.5% for four weeks followed by 0.8% for 47 weeks either with no other exposure or one week after exposure to A-mcthyl-A"-nitro-A -nitrosoguanidinc to initiate stomach carcinogenesis. With catechol alone, the incidence of forestomach papillomas was 1/15 compared with 0/10 in untreated controls. Glandular stomach adenocarcinomas were found in 3/15 rats compared with 0/10 in controls. Catechol increased the incidence of squamous-cell carcinomas of the forestomach induced by the initiator from 5/19 to 19/19 (p < 0.001). In the glandular stomach, the incidence of adenocarcinomas in the pyloric region was 18/19 (p < 0.001) compared with none in rats given only the initiator (Hirose et al., 1987). 

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