A. Brusasco

Multiple pilomatricomas in Rubinstein-Taybi syndrome. A case report

Abstract: Rubinstein‐Taybl syndrome is a multisystem developmental disordar due to an autosomal dominant mutation. It Is clinically defined by the presence of peculiar facles, mental retardation, and bread thumbs and first toes. Important dermatologic findings include hirsutism, keiolds, hemanglomas, and dermatoglyphic abnormalities. We report a 12‐year‐old girl with the typical phenotype of Rubinsteln‐Taybi syndrome, associated wtth numerous ptlomatrloomas. These are benign epithelial neoplasms with hair eel differentiation that may have a familial transmission. Pilomatricomas have not been reported in patterns with Rubinstem‐Taybl syndrome, although their association with myotonlc dystrophy, another autosomal dominant disorder, is well known. Possibilities to explain the association Include contiguous gens syndrome, the action of a piefotropic gene, predisposition to malformations, and mere coincidence.

PITYRIASIS ROTUNDA : REPORT OF A FAMILIAL OCCURRENCE AND REVIEW OF THE LITERATURE

Pityriasis rotunda is an uncommon dermatosis characterized by multiple, widely distributed, strikingly circular hypopigmented or hyperpigmented patches that are slightly scaly. It has been described in Oriental and black patients, usually in association with certain infective or malignant systemic diseases. Pityriasis rotunda is rare in white patients and does not act as a marker of malignancy. Our ultrastructural and histologic findings demonstrated that pityriasis rotunda is more closely related to congenital ichthyoses than ichthyosis vulgaris, contrary to previous reports. On the basis of our studies and a review of the literature, it seems that two types of pityriasis rotunda exist with significant prognostic differences.

Epidermolysis Bullosa Pruriginosa

Epidermolysis bullosa (EB) pruriginosa is a rare clinical subset of dystrophic EB, characterized by marked itching and presence of prurigo-like or lichenoid features. In order to further delineate the phenotype and understand the pathogenesis of this disorder, the clinical, histological and ultrastructural findings of a 19-year-old patient presenting a typical form of EB pruriginosa are described. The prevalence of papular itchy lichenoid lesions, signs of scratching and paucity of blisters at the time of clinical examination may result in incorrect diagnosis and treatment. Microscopic studies of the lesions show the typical findings of dystrophic EB associated with an unusually high density of collagen bundles and absence of elastic fibres in the upper dermis. Itching lichenoid lesions of EB pruriginosa could represent an abnormal dermal reactivity of some patients to their inherited bullous disorder.

Uncommon Clinical Presentations of Juvenile Xanthogranuloma

Two unusual clinical presentations of juvenile xanthogranuloma (JXG), the most common non-Langerhans cell histiocytosis, are described: a flat ‘plaque-like’ and a ‘paired’ form. This report confirms the great variability of JXG. Besides representing a dermatological curiosity, the recognition of these atypical forms of presentation should facilitate the clinical diagnosis of the disorder.

CUTANEOUS MYIASIS CAUSED BY LARVAE OE CORDYLOBIA ANTHROPOPHAGA (BLANCHARD)

Background. Cordylobia anthropophaga (Blanchard) is a nonhematophagous dipteron belonging to the Calliphoridae family. It produces a mylasis called “tumbu fly” or “ver de Cayor” or “mango fly” or “skin maggot fly.”

Proteus syndrome: Ultrastructural study of linear verrucous and depigmented nevi

Proteus syndrome is a rare hamartomatous disorder characterized by multifocal overgrowths that can involve any structure of the body. Clinical manifestations include macrodactyly, hemihypertrophy, subcutaneous masses, exostosis, cerebroid thickening of palms and soles, and linear skin lesions. About 50 cases have been described, but the ultrastructural features of the linear skin lesions have not been characterized. We describe the clinical, histologic, and ultrastructural findings for a 30-year-old patient who had a mild form of Proteus syndrome with linear lesions characterized by a mixed pattern of hyperkeratosis and depigmentation. Light microscopy of the linear nevus showed acanthosis and hyperorthokeratosis. Electron microscopy revealed extensive vacuolation at the interface between melanocytes and keratinocytes, with large aggregations of densely packed granules in the intercellular space. Melanocytes showed only slight degenerative changes. An immunohistochemical study of the expression of epidermal growth factor receptors revealed no significant abnormalities.

Acrokeratoelastoidosis of Costa: a primary disease of the elastic tissue?

A 24‐year‐old black woman from Uganda was seen for treatment of multiple papules on her hands and feet. The lesions corresponded microscopically to foci of hyperkeratosis and acanthosis. Acid orcein stain revealed marked elastic fiber fragmentation. Acrokeratoelastoidosis of Costa (AKE) was diagnosed. The same damage to the elastic fibers was also present in an additional specimen from grossly uninvolved skin. On electron microscopy there were pronounced changes of the elastic fibers with elastolysis in both specimens. This case with generalized damage of the dermal elastic tissue supports the view that elastorrhexis is the key feature of AKE. Accordingly, the disease could be regarded as a primary elastic tissue disorder. The marginal acral keratoderma that is seen in AKE patients could represent epidermal changes secondary to chronic trauma.

Ichthyosis congenita type IV: a new case resembling diffuse cutaneous mastocytosis

The wide phenotypical heterogeneity within the ichthyosis congenita group of diseases is well known. We report a case of a very rare and unusual autosomal recessive ichthyosis congenita, type IV, according to the ultrastructural classification. Our case presented the triad clue for the diagnosis, characterized by follicular hyperkeratosis, prematurity and perinatal complications, but the clinical diagnosis was further complicated by hypereosinophilia and a strongly positive Dariers sign suggesting diffuse cutaneous mastocytosis. The diagnosis was provided only by electron microscopy, which showed the pathognomonic markers of ichthyosis congenita type IV, namely a large number of membrane structures in the stratum corneum and stratum granulosum. As a consequence, correct genetic counselling for the parents was carried out, and they were informed about the benign course of the disease after the complications of the perinatal period. This case is a further example of the reliability of ultrastructural markers in the diagnosis of inherited keratinization disorders, especially those with an unusual clinical appearance.

Unusual hyperpigmentation developing in congenital reticular ichthyosiform erythroderma (ichthyosis variegata)

We present an unusual new clinical feature which developed in a patient with congenital reticular ichthyosiform erythroderma. This rare ichthyotic disorder is characterized by erythematous ichthyotic skin surrounding slowly enlarging areas of normal skin, and by a pathognomonic ultrastructural pattern, namely perinuclear deposits of a filamentous material in vacuolized keratinocytes. At the age of 18 years, a 23‐year‐old woman developed several irregular hyperpigmented macules on her limbs, which were almost black in colour. These lesions have not been observed in the other patients affected by the disease nor, to our knowledge, in other ichthyotic disorders. Electron microscopy and immunohistochemistry demonstrated that the lesions were strictly related to the ichthyotic skin and that their dark colour was especially due to melanosome accumulation in activated dendritic melanocytes. An unusual postinflammatory hyperpigmentation, in which the lack of pigment deposition in the keratinocytes is due to a transfer defect in pathological cells, is hypothesized. A characteristic hyperplastic stimulation of the epidermis is also taken into consideration to explain the lack of a similar picture in other erythrodermic ichthyotic disorders with a continuous inflammatory process.

Hypochromic Reticulated Streaks in Incontinentia Pigmenti: An Immunohistochemical and Ultrastructural Study

Abstract: A 25‐year‐old woman who recently gave birth to a baby affected by classic lesions of incontinentia pigmenti (IP), had hypochromic, atrophic, and reticulated streaks on both lower limbs. Her personal history was unremarkable for IP, and physical examination revealed no other cutaneous signs of the disease. Immunohistochemical and electron microscopic studies were performed on biopsies obtained from both normal and hypochromic skin of the leg. Hypochromic skin showed epidermal atrophy and lack of adnexae, without significant melanocyte abnormality. As demonstrated by this patient, hypochromic reticulated streaks can represent the only cutaneous marker of IP in adulthood. Careful search for such skin lesions in the mother of a child with IP is essential in order to ascertain whether there is a risk of its occurrence in future offspring.