Definition of the features of acquired elastotic hemangioma reporting the clinical and histopathological characteristics of 14 patients

Background: During the last few years, new cutaneous vascular proliferations have been described, including a distinctive clinicopathologic variant of hemangioma, denominated acquired elastotic hemangioma. To date, there is only one series of six cases reported in the literature, thus, the clinical and morphological data of this variant are not well established. Methods: Fourteen cases of acquired elastotic hemangioma were retrieved from the files of the Dermatopathology Unit at Wake Forest University School of Medicine. Results: Acquired elastotic hemangioma affects sun‐damaged skin of upper extremities and neck. Clinically, lesions present as slowly growing, painless, solitary, erythematous plaques. Histopathologically, they are characterized by a horizontal proliferation of capillary blood vessels in the upper reticular dermis in a background of solar elastosis. The vessels have plump endothelial cells that protrude into the vascular lumens in a ‘hobnail’ pattern. Of the 10 cases assessed by immunohistochemistry, 100% (10) expressed CD31 and CD34, 90% (9) expressed D2‐40 and 10% (1) expressed SMA. Conclusion: Acquired elastotic hemangioma is a distinctive variant of hemangioma which should be differentiated from other cutaneous vascular tumors with a hobnail endothelial pattern, including angiosarcoma. The expression of D2‐40 in most cases suggests a lymphatic origin of this acquired vascular proliferation. Martorell‐Calatayud A, Balmer N, Sanmartín O, Díaz‐Recuero JL, Sangueza OP. Definition of the features of acquired elastotic hemangioma reporting the clinical and histopathological characteristics of 14 patients.     

Immunohistochemical evaluation of basal cell carcinoma and trichepithelioma using Bcl-2, Ki67, PCNA and P53

Most basal cell neoplasms with follicular differentiation represent a heterogenous group of tumors. Although may arise anywhere in the skin, these neoplasms commonly occur on the head and neck regions. The majority of these neoplasms are basal cell carcinomas (BCC) and trichoepitheliomas (TE). Overlapping histopathologic features between these benign and malignant tumors are occasionally seen which may create problems in rendering a definitive diagnosis. The intent of this investigation was two-fold: 1) to examine whether there are quantitative differences of the cellular expression of Bcl-2, Ki67, PCNA and P53 between BCC and TE; and 2) to examine the value of these immunostains in differentiating between BCC and TE. Twenty cases of BCC were stained with antibodies for Bcl-2, Ki67, PCNA and P53. The positive cell indices and staining characteristic of these immunostains were compared with those of 20 cases of TE. The cell indices for each group were analyzed statistically utilizing the analysis of variance (ANOVA) technique. Intensity and patterns of Bcl-2 and P53 expression were similar between BCC and TE. The ANOVA analysis showed no statistically significant differences between cell indices for cases stained with antibodies for Bcl-2 and P53 (p=0.49 and p=0.87 respectively) in the two neoplastic groups. There were intense labelling and generalized patterns of Ki67 and PCNA expression in BCC. Conversly, Ki67- and PCNA-labelled cells were much fewer in TEs than those noted in BCCs. Additionally, Ki67- and PCNA-positive cells were limited to the peripheral layers of the neoplastic islands of TEs. There were statistically significant differences between cell indices for cases stained with antibodies for Ki67 and PCNA (p=0.02 and p=0.05 respectively) in the two neoplastic groups. BCC and TE exhibited comparable expressions of Bcl-2 and P53 with similar intensity of labelling and patterns of distribution. This suggests possible similar mechanisms of growth regulation in both neoplasms. However, Ki67 and PCNA labelling was noted with significantly increased numbers and recognizably different patterns in BCCs compared to TEs. This may help explain the significant capabilities in tumor proliferation and the aggressive behavior of BCC compared to the limited growth potential of TE. Additionally, Ki67 and PCNA staining intensity and characteristics may have some value in differentiating between BCC and TE.