Nara Moreira Rocha

Ultrastructure of pitted keratolysis

A 20‐year‐old man presented with pitted keratolysis (PK), demonstrating the typical crateriform pits on the hallux ( Fig. 1 ), ball of the foot, and on the interdigital surface. The involved keratin specimen was obtained by a shaving technique and processed for transmission (TEM) and scanning (SEM) electron microscopy. The patient, who wore only sports shoes, had hyperhidrosis plantaris. He was treated with topical erythromycin with good results. Bacterial cultures from the lesions showed Corynebacterium sp.

Follicular involvement in porokeratosis

JEADV 2007, 21, 104–143

Ecthyma‐like phaeohyphomycosis caused by Cladosporium cladosporioides

A case of cutaneous phaeohyphomycosis caused by Cladosporium cladosporioides in a 50‐year‐old housewife is described. The clinical presentation was an ecthyma‐like crusted lesion on the back of her left hand. Scanning electron microscopy of the culture showed the conidiophores and the limoniform or ellipsoidal conidia, with a slightly verrucous surface. The lesion was removed surgically, with no relapses after 6‐month follow up.

Papulöse akantholytische Dyskeratose

ZusammenfassungDie papulöse akantholytische Dyskeratose ist eine sehr seltene Dermatose, die histologisch eine suprabasale Spaltung mit akantholytischen und dyskeratotischen Zellen zeigt, was dem klassischem Bild des Morbus Darier entspricht, jedoch ist sie erworben und ohne genetische Grundlage. Eine 40-jährige Patientin zeigte ca. 200 kleine keratotische Papeln an beiden Unterschenkeln, deren histologische Untersuchung in das Bild der Keratosis follicularis hineinpasste. Die elektronenmikroskopische Untersuchung zeigte eine verminderte Desmosomenzahl und eine perinukleäre Verteilung der Tonofilamente. Die Läsionen sprachen auf Kryotherapie mit offenem Verfahren gut an.AbstractPapular acantholytic dyskeratosis is a very rare skin disease, which shows a suprabasilar cleft with acantholytic and dyskeratotic cells, simulating the light microscopic picture of Darier disease. In this condition, the lesions are acquired without a genetic basis. We observed a 40-year-old woman with about 200 papules on the lower aspects of her legs; histological examination showed changes similar to Darier disease. Transmission electron microscopy showed a reduced number of desmosomes and perinuclear distribution of tonofilaments. The lesions were successfully treated with cryotherapy with spray technique.

Light and electron microscopy of eruptive collagenoma

Connective tissue nevi may be multiple or solitary, sporadic or familial. Eruptive collagenoma is a variant of the acquired collagenomas characterized by multiple sclerotic papules with an acute onset. A 13‐year‐old girl reported that in the past year, small asymptomatic lesions began to appear in her skin, 30 lesions were seen in the trunk, 5 in the cervical region and 1 in the face. Light microscopy with hematoxylin and eosin staining showed sparse collagen fibers, with Weigert staining diminished elastic tissue was observed. Scanning electron microscopy of the dermis showed individualized collagen fibers forming waved compact masses and not bundles. Transmission electron microscopy also showed sparse and loose collagen fibers with different diameters in cross sections.

Metodologia para observação da camada de cera em maçãs, utilizando microscopia eletrônica de varredura

The fruit epidermis is covered by a thin layer of wax which gives protection to the fruit, mainly against water loss and pathogenic organisms. Several studies using scanning electron microscope have been developed to study that wax. The wax layer visualization through the scanning microscope is difficult due to some problems of sample preparation. The usual procedures cause serious damages to the wax layer or even eliminate it because of its solubilization by some of the reagents. Several researchers have kept the samples at very low temperature (-90oC) during the preparation. Wax observations in Brazil by using electronic scanning microscope have been performed, however in some of them results were not consistent. A relatively simple procedure at the Laboratory of Electron Microscopy at Embrapa Temperate Climate has been tried to overcome such difficulties. Such procedure consists of collecting a small piece of the fruit epidermis (1cm2) taken from the equatorial part of the apples. After sampling it the piece of epidermis is placed on a glass slide hold by the extremes with a sticky tape. The sample on glass slide is kept for 72 hours into a dessicator containing drierite for the sample dehydration. Then, small pieces of the sample (2 mm2) were taken and hold on stubs followed by metalization in gold. Following that, the sample is observed using a Zeiss (DSM - 940A) electronic microscope at a working distance of 15 mm and acceleration voltage of 10 KV. The obtained images made possible to evaluate the action of some experimental treatments which have been used on apples during cold storage.

Scanning electron microscopy of acantholysis in pemphigus foliaceus

We performed scanning electron microscopy of an inverted blister roof in a case of pemphigus foliaceus. The loss of intercellular adherence could be easily seen with low magnification. The acantholytic keratinocytes displayed an irregular and sometimes polygonal contour. Round cells, typically seen in light microscopy, were also observed. The examination of a blister roof allows ultrastructural documentation of the acantholytic changes.

Scanning electron microscopy of lichen sclerosus

Lichen sclerosus is an acquired inflammatory condition characterized by whitish fibrotic plaques, with a predilection for the genital skin. We performed scanning electron microscopy of the dermis from a lesion of lichen sclerosus. Normal collagen fibers could be easily found in deeper layers of the specimen, as well as the transition to pathologic area, which seems homogenized. With higher magnifications in this transitional area collagen fibers are adherent to each other, and with very high magnifications a pearl chain aspect became evident along the collagen fibers. In the superficial dermis this homogenization is even more evident, collagen fibers are packed together and round structures are also observed. Rupture of collagen fibers and inflammatory cells were not found. These autoimmune changes of the extracellular matrix lead to the aggregation of immune complexes and/or changed matrix proteins along the collagen fibers, the reason why they seem hyalinized when examined by light microscopy.

Light and electron microscopy of classical Ehlers-Danlos syndrome.

A 12-year-old boy with difficulty in wound healing and abnormal scars since early childhood was examined. Light microscopy showed loose and disperse dermal collagen with rare bundles, and fibroblasts show an irregular morphology. The fibrous sheath of hair presented a normal parallel distribution of the collagen fibers with normal spindle-shaped fibroblasts. Transmission electron microscopy also found disorganized collagen fibers, which were seen in a same field in longitudinal and cross sections. With high magnifications, an amorphous substance was seen near to loose collagen fibers, which showed variable diameters in cross sections. Scanning electron microscopy of the dermis showed disorganized collagen fibers and with higher magnification, important collagen disarrangement was observed with isolated and crossed-over fibers.

Clinical variability in dystrophic epidermolysis bullosa and findings with scanning electron microscopy

In dystrophic epidermolysis bullosa, the genetic defect of anchoring fibrils leads to cleavage beneath the basement membrane and its consequent loss. A 46 year-old female patient presented blisters with a pretibial distribution associated with nail dystrophy. Her two children had hyponychia and anonychia, which affected all toe nails and the thumb, forefinger and middle finger. DNA sequencing identified in exon 75 of COL7A1 gene a pathologic mutation: c.6235G>A (p.Gly2079Arg). Immunomapping of a blister demonstrated collagen IV (basal membrane) in the blister roof and collagen VII in its floor, confirming dystrophic epidermolysis bullosa. Scanning electron microscopy of an inverted blister showed net-forming collagen attached to the blister roof . The variability found in this family has already been reported and confirms, on a clinical basis, the nail subtype as a dystrophic variant.