Ki-67 immunostaining of normal human epidermis: comparison with 3H-thymidine labelling and PCNA immunostaining.

BACKGROUND: The size of the germinative growth fraction (i.e. the number of actively proliferating germinative cells) of normal human epidermis is still a subject of debate. Ki-67 antigen and PCNA, an auxiliary protein of d-polymerase, are considered as markers of the growth fraction when used under optimal conditions. METHOD: In the present work, we have compared Ki-67 expression (detected with MIB1 antibody) with PCNA expression (detected with PC10 antibody) in biopsies of normal human epidermis fixed in neutral formalin and using antigen retrieval by microwave processing. To obtain additional information, such as the percentage of cells in S phase, biopsies were also incubated in 3H-thymidine before immunostaining. RESULTS: Before microwave treatment, 8% of the basal cells were positive for MIB1 antibody and 7.8% were positive for PC10 antibody. The 3H-thymidine labelling index was 2.8%. The proportion of MIB1-positive cells rose to 19% after antigen retrieval by microwave processing. In the same way, the 3H labelling index rose to 9%. In contrast, PC10 became positive in all epidermal nuclei. CONCLUSION: These results suggest that the growth fraction of the germinative cell population of normal human epidermis is not larger than 20% and is composed of cells with a short cell cycle time.

Granulomatous vulvitis, granulomatous cheilitis: a single diagnosis?

We report two cases of labial swelling (oral and vulvar) with a granulomatous histology in patients with a history of Crohn's disease. The differential diagnosis of granulomatous vulvitis and cheilitis, as well as the symptomatology and treatment of vulvar and oral Crohn's disease are further discussed. To our knowledge, reported cases of vulvar and oral Crohn's disease are quite scarce in the literature, but the disease might be underdiagnosed. We hope to contribute to an earlier recognition and a better management of the vulvar and oral mucocutaneous lesions of Crohn's disease.

p53 Protein overexpression in verrucous carcinoma of the skin.

BACKGROUND: Verrucous carcinoma is a rare variant of well-differentiated squamous cell carcinoma which is characterized by a marked local aggressivity and a poor metastatic potential. Until now, little has been known about the oncogenic mechanisms of this tumor. Recently, extensive investigations have shown that p53 protein, a nuclear protein with oncogene-suppressing activity, may play a crucial role in cell transformation and immunoreactivity for this protein is found in a wide variety of cancers. OBJECTIVE AND METHODS: The aim of the present study is to examine the frequency of immunohistochemically detectable p53 protein by using two monoclonal antibodies (D07 and BP53-12) in 8 cases of formalin-fixed and paraffin-embedded specimens of verrucous skin carcinoma. RESULTS: Overexpression of p53 protein was detected in 6 (75%) of the cases examined with the D07 antibody and in 5 (62.5%) cases with BP53-12. The p53 positivity was shown in a peripheral distribution affecting mainly the basal cell layers of tumoral islands. CONCLUSION: In a high percentage of verrucous carcinoma, p53 immunoreactivity has not been previously described in the literature and our findings suggest that abnormal expression of p53 tumor suppressor protein is a common event in the pathogenesis of this tumor.

Chronic hereditary pancreatitis.

Chronic hereditary pancreatitis is a rare disease accounting for 0.9% of chronic pancreatitis cases. Onset is at an earlier age than chronic alcoholic pancreatitis, often with recurrent painful episodes in childhood. We report the occurrence of hereditary pancreatitis in 3 members of a family over 3 generations.