Case for diagnosis. Radiotherapy-induced pemphigus vegetans.

A 73-year-old male patient developed a poorly differentiated squamous cell carcinoma in the anal canal nine months ago. He was treated with two cycles of 5-fluorouracil and cisplatin and concomitant radiotherapy (6 MeV linear photon accelerator, total dose of 54 Gy), with complete remission. Since forty-five days he presentes a painful perianal and intergluteal erosion with circinate pustular borders. Light microscopy showed pseudoepitheliomatous hyperplasia of the epidermis with microabscesses of inflammatory cells (neutrophils and eosinophils) and acantholytic keratinocytes . Indirect immunofluorescence was positive for IgG, with an intercellular pattern, 1:80 titer. The diagnosis of radiotherapy-induced pemphigus vegetans was established and there was significant regression with oral prednisone (40 mg) and topical betamethasone.

Scanning electron microscopy of dermatofibroma.

Dermatofibroma is a proliferation of spindle cells located in the dermis. We used scanning electron microscopy to examine two histologically confirmed lesions and observed preserved collagen bundles in the perilesional area. In the lesional area, the collagen was denser, without formation of bundles. Higher magnification showed collagen with mesh-like appearance similar to stretched tufts of cotton. Very high magnification evidenced the tufts of cotton and spindle cells measuring 2 to 12 microns.

Cutaneous collagenous vasculopathy: light and transmission electron microscopy.

Cutaneous collagenous vasculopathy is a rare acquired idiopathic microangiopathy characterized by progressive development of diffuse asymptomatic telangiectasias and histologically by accumulation of collagen type IV around the affected vessels. It is diagnosed by its clinical history, confirmed by light microscopy with collagen-specific immunostaining. We report a case of a patient with extensive acquired telangiectasias on the left arm, clinically resembling unilateral nevoid telangiectasia. Dilated blood vessels with thickened walls were observed in the dermis. Immunohistochemistry with collagen IV antibodies revealed marked collagen deposition around the vessels, confirming the diagnosis. Transmission electron microscopy observed duplicate and triplicate vascular basal membrane associated with deposition of amorphous material around the membranes.

Domestic infestation by Sclerodermus sp. with associated skin manifestation.

Sclerodermus sp. is an aculeate insect (Hymenoptera: Bethylidae), measuring 2-4 mm in length. It is a parasitoid and needs termites as hosts to complete its life cycle. It is found in a wide variety of woods and may accidentally sting humans who come near affected wooden objects. A 50-year-old woman presented two episodes of intense pruritic lesions. Clinical diagnosis of insect bite was doubtful since there were no pets at home, lesions had not started during summer and the patient denied rural activities. During a night episode of itching, the patient examined her bed and found 8 insects likely to be responsible for the bites. Scanning electron microscopy revealed typical features of a female of the genus (wingless and with multiple stingers at the lower end of the abdomen).

Scanning electron microscopy of granuloma annulare.

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.

Recurrent aphthous stomatitis in 18-year-old adolescents - Prevalence and associated factors: a population-based study.

BACKGROUND: Recurrent aphthous stomatitis is a painful disorder of unknown etiology. It is among the most common oral mucosal lesions with high prevalence among young adults. OBJECTIVES: To conduct a population-based study with 18-year-old army recruiters to assess its prevalence and associated factors in male adolescents. METHODS: Interview during clinical examination in the army. RESULTS: In this group (2,427 interviewed adolescents) there was a RAS prevalence of 24.9%. Smoking, herpes labialis and socioeconomic status correlated with the outcome. STUDY LIMITATIONS: only male adolescents were interviewed. CONCLUSIONS: Our results showed high prevalence of RAS; association with higher economic level and herpes simplex was found. Protective effect of smoking was confirmed.

Ultrastructural aspects of pseudoxanthoma elasticum.

We report the ultrastructural findings in a case of a 72-year-old black woman with confluent yellowish papules in the cervical region. She had no comorbidities. Ophthalmological examination, electrocardiogram, and echocardiogram were normal. Hematoxylin-eosin staining of the affected skin showed strong alterations in the mid-dermis with irregular clumps of eosinophilic material and loss of the normal parallel arrangement of collagen bundles. Orcein staining revealed that the elastic fibers lost their normal linear configuration, showing clump fragmentation, sometimes forming square structures. Transmission electron microscopy showed aberrant elastic fibers with an irregular outline and heterogenic inner structures. We also observed small elastic fibers. Collagen fibers showed a normal structure with irregular distribution. Scanning electron microscopy revealed important disorganization of collagen fibers and small stone-like deposits measuring around 5 µm associated with bigger structures ranging from 10-16 µm. Higher magnification revealed that these small stone-like structures were sometimes polyhedral-shaped or squared.

Acne scars in 18-year-old male adolescents: a population-based study of prevalence and associated factors.

BACKGROUND: Acne vulgaris is a pilosebaceous follicle disorder affecting over 85% of adolescents to some degree. It frequently causes psychological distress that may persist into adulthood due to scarring. Little information about post-acne scarring epidemiology is available. OBJECTIVES: To describe prevalence, distribution patterns and associated factors of acne scarring in young males, drawing on a representative population sample from a southern Brazilian city. METHODS: A cross-sectional study was undertaken during presentation for military service, which is compulsory for all 18-year-old males. A questionnaire was applied, covering topics like diet, smoking habits, ethnicity, family structure, socio-economic level, as well as specific questions about active acne and resulting scars. Dermatologists conducted the clinical examination. RESULTS: A total of 2,201 male adolescents were interviewed and examined. The overall prevalence of acne scarring was 22%. The malar region was the most frequently involved, present in 80% of affected individuals, followed by the frontal region (31.5%), back (17%), anterior chest (8.2%) and mentonian region (6.4%). Correlation between the intensity of clinical acne and the presence of scars was found, but no association was observed with educational level, smoking, ethnicity, obesity or socio-economic status. CONCLUSIONS: There is a high prevalence of acne scars among this population. This is the first study to ascertain a correlation between acne scarring and factors such as socio-economic status and educational level. The direct relation between acne severity and scarring indicates that prompt and effective treatment is the best way to reduce scarring.

Infantile generalized hypertrichosis caused by topical minoxidil.

Rare cases of hypertrichosis have been associated with topically applied minoxidil. We present the first reported case in the Brazilian literature of generalized hypertrichosis affecting a 5-year-old child, following use of minoxidil 5%, 20 drops a day, for hair loss. The laboratory investigation excluded hyperandrogenism and thyroid dysfunction. Topical minoxidil should be used with caution in children.

Pili canaliculi as manifestation of giant axonal neuropathy.

Giant axonal neuropathy is a rare autosomal recessive neurodegenerative disease. The condition is characterized by neurons with abnormally large axons due to intracellular filament accumulation. The swollen axons affect both the peripheral and central nervous system. A 6-year old female patient had been referred to a geneticist reporting problems with walking and hypotonia. At the age of 10, she became wheelchair dependent. Scanning electron microscopy of a curly hair classified it as pili canaliculi. GAN gene sequencing demonstrated mutation c.1456G>A (p.GLU486LYS). At the age of 12, the patient died due to respiratory complications. Dermatologists should be aware of this entity since hair changes are considered suggestive of GAN.

Scanning electron microscopy of superficial white onychomycosis.

Superficial white onychomycosis is characterized by opaque, friable, whitish superficial spots on the nail plate. We examined an affected halux nail of a 20-year-old male patient with scanning electron microscopy. The mycological examination isolated Trichophyton mentagrophytes. Abundant hyphae with the formation of arthrospores were found on the nail's surface, forming small fungal colonies. These findings showed the great capacity for dissemination of this form of onychomycosis.