Clinical features. Benign fibrous histiocitoma isthe cellular variant of dermatofibroma and is more frequent in childhood of the fibrous variant. The latter is the most frequent tumor in adults, especially inwomen (1). On light microscopy, benign fibrous histiocytoma is characterized by cells with round or oval nucleus and large, well demarcated cytoplasm, distributed according to a storiform pattern (3). In childhood the differential diagnosis should be made clinically with other more frequent proliferations, such as pilomatrixoma, which usually has a more irregular surface, and juvenile xanthogranuloma, usually arising more precociuously and rapidly undergoing xanthomization, and histologically with malignant fibrous histiocytoma, which presents greater cell polymorphism and atypical mitoses, and with dermatofibrosarcoma protuberans, which is barely demarcated and presents atypical mitoses.
Clinical features. Fibrous hamartoma of infancyis usually an isolated hypodermic nodule (1, 5), often on central location -armpits, nape of the neck,groins and root of limbs- rather than acrolocated (4). Fibrous hamartoma of infancy can spontaneouslyregress and its removal is followed by local relapsein less than 15% of cases (3). The histological examination (2) shows rather cell-poor fibrous trabeculae, whorls of immaturespindle cells plunged in a mucoid matrix and maturefat tissue. Some problem of differential diagnosis may arise when the histological examination shows only one component of the tumor. In these cases the presence of only immature cells may lead to diagnose a malignancy, whereas the presence of only mature fat tissue may lead to diagnose lipomaand the presence of only spindle cells may lead to diagnose myoma or neuroma.
Acanthosis nigricans (AN) is a syndrome with variable clinical significance ranging from marker of moderate endocrine imbalance to marker of malignancy. The most frequent form of AN, which therefore could be called AN vulgaris, is AN associated to obesity. Here is reported a case of AN associated to obesity. Physicians should be aware that this form is due to insulin resistance secondary to obesity and that insulin resistance, when the pancreas works, is responsible for hyperinsulinemia. The latter is responsible in malesfor AN and in females for AN and hyperandrogenemia (HA). The treatment of AN vulgaris is based, besides the topical therapy, on the correction of obesity. When the latter goal cannot be achieved, metformin hydrochloride should be given. This biguanide drug increases both the peripheral response to insulin and the cellular glucose metabolism. Moreover, it decreases the delayed glucose intestinal absorption and inhibits hepatic glucogenesis.
Multiple dermatofibromas have been so far reported in systemic lupus erythematosus and in HIV infection. A further case of multiple dermatofibromas in a girl affected by systemic lupus erythematosus and followed up from the age of twelve is reported and its pathogenesis is discussed.
Epidermal necrolysis is characterized by large flaccid blisters. The latter are due to hematogenous spread of epidermolytic toxins and thus may affect the entire skin surface. The responsible factors maybe multiple, mainly viruses, drugs and Staphylococcus aureus. In childhood viruses and Staphylococcus aureus are responsible for the most frequent and severe forms. The differential diagnosis is crucial to immediately start antibiotics in the staphylococcal form.
Segmental vitiligo (SegV) is more common in children than in adults: in the last 10 years among 255 cases of vitiligo in the first 12 years of age we registered 88 cases of SegV, 85 of systemic (SysV), 45 of isolated perinevic (PnV ) and 37 of focal vitiligo (FV); PnV was also present in 8/85 cases of SysV, in 4/88 of SegV and in 4 of 37 of FV. Leucotrichia, which is clearly visible when it hits terminal hair (2), was observed in 8 cases, 5 of which were of SegV. Leucotrichia is usually considered a poor prognostic factor; progression from SegV to SysV was shown in 26 out of 127 (20,4%) cases in a non pediatric population (1); the presence of leucotrichia is - along with halo nevi and skin involvement more than 1% - one of the factors associated to progression of vitiligo from Vseg to VSIS (1). Only 3/88 (3,4%) pediatric patients in our series passed from SegV to SysV in the first year from the onset of the disease.
You have to think of a possible dermatitis artefacta when the history and physical examination are not reminiscent of any known skin disorder. In this case the history did not show any infectious, drug or exogenous factor and showed the spontaneous and quick regression of the lesions. The physical examination showed lesions only on the right hemisoma but without a metameric distribution or along the lines of Blaschko. Another finding suggesting dermatitis artefacta is the presence of lesions in exposed and then visible sites; in our case the lesions were present in covered but easily accessible sites. The finding that reinforced the hypothesis of dermatitis artefacta was the presence of lesions only on the right hemisoma in a left-handed guy. Once you make the diagnosis of dermatitis artefacta it is useless to discover the precise causal mechanisms; on the other hand, it is important with the help of the psychologist to overcome the basic imbalance of the patient.
A self-destructive behavior, and in particular self-cutting the skin is not exceptional and typically begins in adolescence. A multicenter survey conducted on over 12,000 European teenagers (1) showed that 27.6% had carried out voluntarily the injuries, most occasionally, 7.8% on a repetitive basis. The lesions may be parallel or crossed, more or less deep cuts or drawings or inscriptions. The teenager who cuts does not make that to show others his/her injuries as happening in dermatitis artefacta. For this reason he/she does not choose sites exposed as the face and hands, but the most accessible sites that can be hidden, so mainly the limbs, particularly the wrists, forearms and arms prevalently on the non-dominant limb, thighs and legs. The lesions are then discovered by chance; on the other hand, the teenager who cuts him/herself publicly, in visible locations or that flaunts the injuries and continues to carry out them repetitively has a borderline personality or psychiatric disorders (2). The self-cutting teenager procures secretly the injuries not to attract the attention of others as in dermatitis artefacta, but as a remedy to a situation of psychological stress, resorting to physical pain to silence a stressful psychological situation, for example feelings that cause anxiety, anger, depression (2).
When in a prepuberal child a melanocytic proliferation is first observed due to its rapid growth, in the majority of cases we are dealing with a Spitz-Reed nevus (SRn), more rarely with a blue nevus. The natural history of the SRn, scarcely known because the nevus is usually removed, shows an initial growth phase for a period of 6-12 months, followed by a phase of involution that in the hypopigmented form can lead to the clinical disappearance of the nevus. The hyperpigmented SRn in the involution phase tends to flatten when raised; when already flat, it takes a more regular outline for the disappearance of peripheral pseudopods. Dermoscopically, the nevus from an early globular stage switches to a phase of pseudopodia, then of thin streaks till ultimately acquiring an appearance indistinguishable from a common melanocytic nevus, usually with homogeneous at the center and reticular at the periphery structure.
When we type in Pubmed “targetoid “ appear 230 reports which are divided mainly into two categories: those with multiple lesions, ranging from hemorrhagic edema of the newborn to bites of bedbugs, and those with only one hemorrhagic targetoid lesion around a neoformation. In the latter case we are dealing almost exclusively with a lesion that is called targetoid hemosiderotic hemangioma. It is really a hemolymphatic malformation (1) that spontaneously or following trauma undergoes a hemorrhage; the latter then spreads to the surrounding skin. However, this bleeding with centrifugal evolution is not exclusive of targetoid hemangioma. It can be found in other benign lesions, especially in melanocytic nevus. The morphological variation of targetoid hemosiderotic melanocytic nevus is so sudden as to exclude a malignant transformation (2).