Pulmonary arteriovenous malformations in children and young adults

Authors observed five cases of lung arteriovenousmalformations in children and young adults. Clinical data and morphological pictures of these lesions were presented

Microvascular density and mast cells in benign and malignant pheochromocytomas

Pheochromocytomas, uncommon adrenal tumors, have an uncertain behavior. Recently, PASS criteria were proposed for differentiating between benign and malignant cases. These are not perfect, however. The aim of the study was to investigate angiogenesis and mast cell density in context of the clinical behavior and morphologic characteristics of pheochromocytomas. Mean intratumoral chymase positive cell count was 14.50 for malignant, 15.73 for benign cases; mean subcapsular chymase positive cell count was 12.50 for malignant, 11.27 for benign cases.Mean intratumoral tryptase positive cell count was 17.50 for malignant and 17.91 for benign cases; mean subcapsular tryptase positive cell count was 15.25 for malignant and 15.73 for benign cases.Mean intratumoral CD31 positive vessel count was 46.98 for malignant and 51.02 for benign cases; mean subcapsular CD31 positive vessel count was 44.86 for malignant and 39.81 for benign cases. Mean intratumoral CD105 positive vessel count was 37.84 for malignant and 35.95 for benign cases; mean subcapsular CD105 positive vessel count was 26.36 for malignant and 22.03 for benign cases. The differences between benign and malignant cases were not significant. All the vascular counts were correlated with mast cells counts. PASS index was inversely correlated with mast cell counts

Melanomas and dysplastic nevi differ in epidermal CD1c+ dendritic cell count

Background. Dendritic cells could be involved in immune surveillance of highly immunogenic tumors such as melanoma. Their role in the progression melanocytic nevi to melanoma is however a matter of controversy. Methods. The number of dendritic cells within epidermis, in peritumoral zone, and within the lesion was counted on slides immunohistochemically stained for CD1a, CD1c, DC-LAMP, and DC-SIGN in 21 of dysplastic nevi, 27 in situ melanomas, and 21 invasive melanomas. Results. We found a significant difference in the density of intraepidermal CD1c+ cells between the examined lesions; the mean CD1c cell count was 7.00/mm2 for invasive melanomas, 2.94 for in situ melanomas, and 13.35 for dysplastic nevi. The differences between dysplastic nevi and melanoma in situ as well as between dysplastic nevi and invasive melanoma were significant. There was no correlation in number of positively stained cells between epidermis and dermis. We did not observe any intraepidermal DC-LAMP+ cells neither in melanoma in situ nor in invasive melanoma as well as any intraepidermal DC-SIGN+ cells in dysplastic nevi. Conclusion. It was shown that the number of dendritic cells differs between dysplastic nevi, in situ melanomas, and invasive melanomas. This could eventually suggest their participation in the development of melanoma