Abstract: Light microscopy of granuloma annulare shows mucin deposition with lympho-histiocytic infiltrate. We describe the ultrastructural three-dimensional aspects of a typical case of granuloma with characteristic histopathological findings. At the ultrastructural level, affected collagen bundles and granular mucin deposition were observed. Round cells corresponding to lymphocytes were identified. Bigger oval cells, corresponding to isolated or palisading histiocytes were also found. The ultrastructural aspects overlap with light microscopy and contribute to its iconographic documentation.

O líquen escleroso é uma afecção inflamatória caracterizada por placas esbranquiçadas fibróticas ocorrendo preferentemente na pele genital. Realizamos exame com microscópio eletrônico de varredura da derme de uma lesão de líquen escleroso. Ao exame as fibras colágenas normais puderam ser facilmente identificadas, bem como a transição para a área alterada, a qual aparece homogeneizada. Nessa área as fibras parecem aderidas umas às outras e com aspecto em colar de pérolas. Na derme superficial essa homogeneização é ainda mais evidente, com as fibras bem aderidas e ainda com as estruturas arredondadas. Ruptura das fibras e células inflamatórias não foram observadas. Os fenômenos autoimunes que ocorrem na matriz extracelular nessa enfermidade devem levar à agregação de imunocomplexos e/ou proteínas alteradas nas fibras colágenas, por essa razão elas aparecem hialinizadas na microscopia óptica.

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.

Trata-se de dois casos raros de cistos de inclusão epidérmica intragonadais, cuja etiologia permanece controversa, sendo uma hipótese a de teratomas monodérmicos abortivos, sem componentes mesodérmicos e endodérmicos. Devido a resultados inespecíficos dos exames ultrassonográficos, torna-se difícil afastar a possibilidade de neoplasia e o tratamento padrão permanece sendo, portanto, a terapia radical. O diagnóstico definitivo, em ambos os casos, foi firmado pelo exame anatomopatológico.

Two rare cases of intragonadal epidermoid inclusion cysts are described. Their etiology remains controversial and a possible hypothesis is monodermal abortive teratomas, with no mesodermal and endodermal components. As the ultrasound test results were inconclusive, it became difficult to rule out the possibility of neoplasm. Therefore, patients were submitted to radical therapy. The definitive diagnosis for both cases was provided by the anatomopathological examination.

Paciente masculino de 12 anos relatou dificuldade em cicatrizar, seguido por cicatrizes de aspecto infrequente . A pele dos joelhos e cotovelos é fina, brilhante e protrusa, caracterizando pseudo- tumores. Além disso apresenta hiperelasticidade cutânea e articular. A microscopia óptica demonstrou raros feixes colágenos, as fibras colágenas encontram-se dispersas. O tecido elástico está presente e secundariamente irregular. A microscopia eletrônica de transmissão também observou fibras colágenas desorganizadas e com cortes transversais em grande aumento evidenciou diâmetros variados e contorno irregular das mesmas. A microscopia eletrônica de varredura da derme demonstrou raros feixes colágenos e fibras colágenas isoladas e entrecruzadas

A 12-year-old boy with difficulty in wound healing and scars of unusual appearance was examined. Thin, shiny and protruding skin, characterizing pseudotumoral lesions, was observed on his knees and elbows. Loose joints and increased skin elasticity were also observed. Light microscopy showed rare collagen bundles and loosely dispersed collagen fibers. Irregularly distributed elastic tissue was observed, and transmission electron microscopy revealed disorganized collagen fibers. In cross sections under high magnifications, fibers of varying diameters could be seen, as well as an irregular fiber outline. Scanning electron microscopy of the dermis showed disorganized collagen fibers, which were rarely arranged in bundles. Isolated and crossed-over fibers were also found