Stromal p16 expression differentiates endometrial polyp from endometrial hyperplasia.

Endometrial polyps are very common benign endometrial lesions, but their pathogenesis is poorly understood, except for a few studies indicating the possibility of benign stromal neoplasm. Although the histopathological diagnosis of endometrial polyp on a surgical specimen is straightforward, it is often difficult to differentiate endometrial polyp from endometrial hyperplasia on a biopsy or curettage specimen. Presently, there is no immunohistochemical marker helpful in this differential diagnosis. In this study, we examined p16 expression in 35 endometrial polyps and 33 cases of endometrial hyperplasia that included 16 simple hyperplasias, 14 complex atypical hyperplasias, and 3 complex hyperplasias without atypia. Stromal p16 expression differed significantly between the two groups; it was seen in 31 (89 %) endometrial polyps, but in only 1 (3 %) endometrial hyperplasia. The percentage of p16-positive stromal cells ranged from 10 to 90 % (mean, 47 %) and the positive cells tended to be distributed around glands. Six cases of endometrial hyperplasia within an endometrial polyp were also examined and all cases showed stromal p16 expression. There was no difference in glandular p16 expression between endometrial polyps 33 (94 %) and hyperplasia 27 (82 %). The p16-immunoreactivity was mostly confined to metaplastic epithelial cells in both groups. Stromal p16 expression might be a peculiar characteristic of endometrial polyp and constitute a useful marker for the diagnosis, especially in fragmented specimens from biopsy or curettage. Stromal p16 expression might be a reflection of p16-induced cellular senescence, which has been documented in several benign mesenchymal neoplasms.

Five cases of necrotizing fasciitis: lack of skin inflammatory signs as a clinical clue for the fulminant type.

Herein, we describe five patients with necrotizing fasciitis (NF) who had variable outcomes and clinical manifestations. At the onset, all patients exhibited purpura with or without blister and ulceration accompanied by severe pain and tenderness in the affected skin. Out of five patients, three lacked inflammatory signs such as redness and heat, and two of the three patients showed fulminant progression and died despite intensive treatments including surgical debridement, antimicrobial therapy, close monitoring and physiological support. Tissue specimens from the patients without skin inflammatory signs showed mild neutrophil infiltration in addition to necrosis from the epidermis to subcutaneous fat, and variable amounts of thrombi. Furthermore, numerous bacteria were detected by Gram stain. By contrast, the remaining two patients with skin inflammatory signs revealed slower progression, and tissue specimens from both patients showed heavy neutrophil infiltration, but bacteria were hardly detected. Therefore, these cases suggest the possibility that the paucity of skin inflammatory signs, such as redness and heat, in NF may be a clinical clue to predict the fulminant type.

Endometrial atypical hyperplasia with clear cell change spreading throughout the endometrium.

An unusually rare case of atypical endometrial hyperplasia with clear cell change (metaplasia) spreading through almost the whole endometrium of a 37-year-old woman with infertility and abnormal bleeding is reported.