Although usually considered a non-pathogenic parasite in parasitological textbooks, Demodex folliculorum has been implicated as a causative agent for some dermatological conditions, such as rosacea-like eruptions and some types of blepharitis. Several anecdotal reports have demonstrated unequivocal tissue damage directly related to the presence of the parasite. However, this seems to be exceedingly rare, in contrast with the marked prevalence of this infestation. We have had the opportunity to observe one of such cases. A 38-year-old woman presented with rosacea-like papular lesions in her right cheek. Histopathological examination revealed granulomatous dermal inflammation with a well-preserved mite phagocytized by a multinucleated giant cell. This finding may be taken as an evidence for the pathogenicity of the parasite, inasmuch as it does not explain how such a common parasite is able to produce such a rare disease.

Abdominal angiostrongyliasis is a parasitic disease caused by Angiostrongylus costaricensis, a metastrongylid nematode with wide geographic distribution, occurring from the United States to Argentina. In Brazil, the disease has been reported from the States of Rio Grande do Sul, Santa Catarina, Paraná, São Paulo, Federal District of Brasília and Minas Gerais. We report here a case of abdominal angiostrongyliasis in a 9-year-old girl, from Itatiba, State of Espirito Santo, Brazil, submitted to exploratory laparotomy for acute abdomen. Extensive inflammatory lesions of terminal ileum and cecum, with perforations of the first, were present, and ileocecal resection was performed. The pathological picture was characterized by transmural inflammatory granulomatous reaction, extensive eosinophilic infiltration, eosinophilic vasculitis and the presence of worms within a mesenteric artery branch, with histological features of metastrongylid nematodes. This case report contributes to a better knowledge of the geographic distribution of this parasite in Brazil, suggesting that abdominal angiostrongyliasis may represent a disease of medical importance, more than a rarity of academic interest.

No abstract

We describe a schistosomal polyp in the anus of a 24-year-old patient, born in Viçosa, State of Minas Gerais, and living in Belo Horizonte, State of Minas Gerais. From 8 to 13 years of age, he swam in the rivers that bathe Viçosa. The histopathological examination has shown a lesion, lined by a keratinized squamous epithelium, ulcerated, with granulomas, centered or not by Schistosoma mansoni egg, laid, in loco, by the female present in the vascular lumen of a vein of the hemorrhoidal plexus. There was also a diffuse, nonspecific inflammation in the dermis. The patient was treated with praziquantel. Four months after the treatment, sigmoidoscopy showed a normal rectal mucosa, and negative oogram and stool tests. Ultrasound of abdomen was normal.

Anorectal melanomas should be characterized by location (anal, rectal and anorectal), color, size, shape and mobility and microscopically, by melanocyte subtypes, grade of melanin pigmentation, junctional changes in the squamous epithelium, atypical mitotic index, cellular atypia, inflammatory infiltrate, vascular and perineural invasion, sentinel lymph node, and anorectal parietal penetration. Anorectal melanomas must be staged by American Joint Committee on Cancer (AJCC) and/or TNM Classification of Malignant Tumours (TNM) criteria. As melanocytes can present with several shapes, sometimes the differential diagnosis with other tumors in this region may be difficult. Because of this, immunohistochemistry is mandatory to attain a precise diagnosis. This study is a report of 14 patients with anorectal melanoma, in whom histological examinations were remade and immunohistochemistry was performed with several markers for melanocytes and for other tumor cells of the anorectal region, properly establishing the diagnosis. The most rational surgery is the extended local resection, when the disease is restricted to the area or the abdominoperineal resection to advanced lesions. Regardless of the technique used, the results are always poor. The authors deny any efficacy of current radio and/or chemotherapy as part of treatment of anorectal melanoma. Target-therapy for metastatic disease has been considered a good strategy, but the results are still inconclusive.