The cellular proliferations of the skin, especially malignant tumors, are rare in children as compared with adults. However, such proliferations are concentrated in the first months of age (Fig. 790). According to some Authors (25), this is why in the neonatal period whatever tumefaction of doubtful diagnosis should induce to rule out tumors. Characteristically, the proliferations of the first months present a very wide clinical spectrum, ranging from an isolated cutaneous lesion to the generalized involvement of the skin till the multisystem involvement. Their prognosis is also very variable, ranging from the spontaneous regression to the exitus. The tendency to the spontaneous regression is much higher at this age. It does not depend on the cell type affected, being practically detectable in all the neonatal proliferations, both benign and malignant, from hemangioma to mastocytoma, to juvenile xanthogranuloma, myofibromatosis, Langerhans cell histiocytosis and neuroblastoma. (...).
Tuberous sclerosis is a phacomatosis, namely an inherited disorder involving the skin and the nervous aystem. Besides the classic forms with typical skin lesions (congenital hypomelanic macules, angiofibromas, Koenen tumors, shagreen patches) and characteristic neurological lesions (seizures), do exist minimal forms, which can present only cutaneous lesions, mainly angiofibromas. In the past, the latter were called sebaceous adenomas, mainly due to their distribution around the nose, which is a region particularly rich in sebaceous glands. In some cases angiofibromas of tuberous sclerosis should be differentiated from inflammatory acne.
Histiocytosis is the most frequent infantile proliferation after mastocytosis. Histiocytosis is due to the proliferation of the histiocyte. From the undifferentiated histiocyte derive two more differentiated cells, namely the monocyte-macrophage and the Langerhans cell. This is why there are two types of histiocytosis, namely non-Langerhans histiocytosis, which is due to the proliferation of monocytes-macrophages, and Langerhans cell histiocytosis. Similarly to mastocytosis and all the proliferations of the first months of life, the clinical spectrum and prognosis of histiocytosis is very wide, ranging from an isolated lesion of the skin or other organs to the generalized involvement of the skin, till the multisystem involvement of the organism. The prognosis is also extremely variable, ranging from the spontaneous regression within months or years to the death in a few weeks. The biological significance of histiocytosis is under discussion. According to some authors, histiocytosis is a self-healing, reactive, hyperplastic proliferation, whereas other authors believe that it is a malignant, potentially lethal neoplastic process. We are treating only the most frequent forms in childhood of this extremely complex chapter, namely juvenile xanthogranuloma and cephalic histiocytosis among the non Langerhans histiocytoses and finally Langerhans cell histiocytosis.
Lymphomas are malignant tumors deriving from the proliferation of cells setting up the immune system. As these cells normally circulate with the blood in the whole organism, lymphomas are generalized tumors from their appearance. However, exceptions do exist leading the Authors of the European Organization for Research and Treatment of Cancer (EORTC) to say that morphologically identical lymphomas, when arising in different organs, are clonal proliferations of distinct lymphocyte subpopulations, which are in some way related to the organ where the lymphoma arose (45). Lymphomas are much less frequent in children as compared with adults. However, some Authors (5) established that 1/6,000 children under the age of 15 develops lymphoma. According to these Authors, the frequency of lymphomas follows only that of leukemias and brain tumors. (...)
The number and distribution of melanocytic nevi at the age of ten were investigated in 244 students. The latter were chosen at random in 15 classes of the primary school of Bari (Italy). Besides the age and sex, in these subjects were investigated the presence of ephelides, nonmelanocytic nevi, the total number of melanocytic nevi, the number of such lesions for each site -head, trunk, upper and lower limbs- and the site of the largest nevus. Ephelides were found in 49 subjects (19%). Among the nonmelanocytic nevi, hyperpigmented nevus was the most frequent (19 cases -8%-). 66% of students showed a total number of melanocytic nevi higher than 10. This percentage was 72 in subjects with ephelides. The highest concentration of melanocytic nevi was on the head, whereas the lowest was on the lower limbs. No difference was shown between sexes with regard to the number and distribution of melanocytic nevi.
Vitiligo and hypopigmented nevus are responsible for white cutaneous patches. The latter can appear in the first years of life. Vitiligo is an acquired disease. It is characterized by an autoimmune disorder leading to the destruction of the melanocytes. On the other hand, hypopigmented nevus is a malformation disorder occurring during the fetal life. It probably consists of a defective transport of melanin inside the keratinocyte. Hypopigmented nevus often affects only a cutaneous segment. Hypopigmented nevus should be differentiated from segmental vitiligo, which is a clinical variant of vitiligo, more frequent in children than in adults. Due to significantly different clinical course, the differential diagnosis between the two disorders is important. Hypopigmented nevus is less white and thus less visible of vitiligo. Moreover, it persists unchanged with time. On the other hand, segmental vitiligo is an evolutive disease and thus may worsen or, more often in children, improve and almost completely regress. The differential diagnosis between the two disorders also leads to a different therapeutical approach.
The antihistamines are the drugs most widely prescribed in pediatric dermatology, although not always rationally. Interestingly enough, the antihistamines are usually prescribed in children because of effects that, on the other hand, are considered as unwanted side effects in adults. As a matter of fact, we can consider the sedative effect. To overcome the latter many studies were carried out, leading to the synthesis of second-generation antihistamines, which are devoid of sedative effect. We can also consider the increased appetite, which led to excessively prescribe cyproheptadine. The antihistamines are rationally prescribed in urticaria, especially acute urticaria, and in the most severe cases of mastocytosis. On the other hand, their usage is debated in atopic dermatitis and in the itchy disorders due to other causes. Their debated activity in these disorders is probably related to an effect, which is usually considered a side effect of the first-generation antihistamines, namely the sedative effect on the central nervous system (12). (...).
Eruptive angioma (EA) is a benign proliferation of angiopoietic tissue rapidly growing in a few weeks till causing erosion of the epidermis and bleeding. In the past its most frequent synonym was pyogenic granuloma, whereas the most recent term of “lobular capillary hemangioma” was proposed by Mills et Al. (17). Since 1982, starting from the report of Mulliken and Glowacki (18) there were some attempts of classification of lesions, which in the past had been all included in the chapter of angioma. These attempts are laudable because they try to introduce pathological and functional criteria, in contrast with the previous classification using exclusively clinical criteria. In a new classification (24) all the previously known angiomatous lesions are classified into the categories as follows: hamartomas, malformations, dilatations of preexisting vessels, and proliferations, the latter being in turn subdivided in hyperplasias, benign neoplasms and malignant neoplasms. Unfortunately, the borders between the various entities, for instance between hyperplasia and benign neoplasm or even between benign and malignant neoplasm (23) are not always well defined as it would be necessary for a classification, because nature does not jump.(...).
The rarity of prepubertal melanoma prevents a statistical evaluation of data and a comparison with the data of melanoma in adults. We tried to fill this gap by reviewing 289 cases published in the relevant literature of the last century. Although taking into account their understandable lacunas, these data allowed us to do some considerations. The distribution of cases per year in the first 12 years is uniform. The female is slightly more frequently -54.7%- affected by malignant melanoma as compared with the male even at this prepubertal age. The site distribution in the two sexes is different as compared with adults. In females the trunk is more frequently affected -41.56%- than in males -30.71%-. Moreover, the lower limb is almost equally affected in females -25.32%- and in males -26.77%-. The head is more significantly -27.76%- affected in the prepubertal age as compared with adults -16.63%-. The most important favoring factor at this age -present in one third of the cases- is congenital melanocytic nevus, especially the giant type. The number of died children is significantly affected by the presence of a giant congenital melanocytic nevus -70.15%-, whereas it is not influenced by the age and the sex -37.40% in males and 39.24% in females-. The number of died children is also influenced by the presence of adenopathy -63.40% versus 6.17% in cases without adenopathy-.
Epidemiological data regarding 1,504 cases of primary malignant melanoma of the skin removed and diagnosed in Bari from 1975 to 2000 are reported. Particularly, besides the total number of cases, figures per year, sex, age and site of the primary tumor are reported. The prevalence of melanoma is increasing even in Bari of about 10% per year. Females (55%) are affected slightly more frequently than males. With regard to the age, the most affected five-year period is between 56 and 60, with 75% of cases included between 36 and 75 years. Three cases of prepubertal melanoma with a prevalence of 0.2% of the cases are reported. Particular attention was paid to the different distribution per site according to the sex. Once confirmed the more frequent involvement of the lower limb in females and of the trunk in males, we subdivided in age groups the cases of melanoma. We showed that this different localization in the two sexes starts after 30 years and persists after 60 years. As the more frequent localization on the lower limb in the female lacks in the 16-30 age group and on the other hand is present in the over sixty age group, the involvement of this site is probably not exclusively related to sex-linked hormonal factors.