Clinical and histopathological aspects of the insect bite hypersensitivity in horses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Padrões histopatológicos das lesões descamativas e ulcerativas da pele em cães com leishmaniose

Canine visceral leishmaniasis is an endemic infectious disease in some São Paulo state regions and even though it is a systemic disease, in the dog, the main clinical sign is dermatological. Thirty dogs with positive results in serology and parasitological exams for leishmaniasis from Aracatuba city were evaluated. They just showed dermatological signs and were divided in two groups, one with exfoliative(n = 15) and other with ulcerative (n = 15) lesions. Histopathological. patterns in the group of exfoliative lesions were: periadnexial dermatitis (5115, 33,3%), superficial perivascular dermatitis (1/5, 6,6%), nodular dermatitis (1115, 6,6%) and mixed dermatitis (8/15, 53,3%), including intersticial/periadnexial dermatitis (1/8, 12,5%). lichenoid/perivascular superficial and deep dermatitis (1/8, 12,5%), perivascular superficial and deep/periadnexial dermatitis (1/8, 12,5%) and superficial perivascular/perianexial dermatitis (5/8, 62,5%). In the group of ulcerative lesions, the histopathological patterns were: perivascular superficial and deep dermatitis (5115, 33,3%), diffuse dermatitis (3/15. 20%), periadnexial dermatitis (2/15, 13,3%), nodular dermatitis (1/15, 6,6%) and mixed dermatitis (4/15, 26,6%), including intersticial/perivascular superficial and deep dermatitis (1/4, 25%), nodular/periadnexial dermatitis (1/4, 25%), fibrosing/perianexial dermatitis (1/4. 25%) and perivascular superficial and deep/periadnexial dermatitis(1/4, 25%). Parasites were found in eight dogs (8/15, 53,3%) with exfoliative dematitis and seven (7/15, 46,6%) with ulcerative dermatitis.

Morphologic changes and the expression of alpha-melanocyte stimulating hormone and melanocortin-1 receptor in melasma lesions: A comparative study

Melasma is a common acquired symmetrical hypermelanosis characterized by irregular light- to dark-brown macules on sun-exposed skin areas. The literature shows few studies on its physiopathogeny. However, changes in α-melanocyte stimulating hormone (α-MSH) secretion and melanocortin-1 receptor (MC1-R) expression may play a role to trigger this condition. Biopsies were taken from both melasma skin and adjacent perilesional normal skin of 44 patients. The biopsies were submitted for hematoxylin and eosin and Fontana-Masson staining and immunohistochemistry with Melan-A, α-MSH, and MC1-R, and processed for transmission electron microscopy. In some cases, they were submitted to MC1-R gene expression analysis by real-time polymerase chain reaction. Increased lymphohistiocytic infiltrate and solar elastosis, higher epidermal melanin were observed in melasma skin. Electron microscopy revealed a greater number of mature melanosomes in keratinocytes and melanocytes, and more prominent cytoplasmic organelles in melasma skin. There was no difference in melanocyte number between areas. However, melanocytes were larger and more dendritic in melasma skin. Immunohistochemistry with α-MSH and MC1-R showed significant labeling in melasmic epidermis but MC1-R messenger ribonucleic acid (RNAm) did not show significant quantitative difference between melasma and normal skin. © 2010 by Lippincott Williams & Wilkins.

Focal invasiveness in complete histological analyses of a large acral lentiginous melanoma

Background: Acral lentiginous melanoma is a melanoma with poor prognosis which is frequently diagnosed at an advanced stage. Since the thickness of tumour is one of the main prognostic factors, this case can exemplify how important complete histological analyses looking for focal invasiveness can be.Case report: A 77 year-old woman with a black spot with slow progressive growth on the left plantar region. She sought medical attention due to the expansion onto the dorsal surface of toes. The lesion had irregular borders and had spread to half the plantar surface. Histopathology confirmed the clinical suspicion of acral lentiginous melanoma Clark level IV and 2.6 mm Breslow thickness. The surgical specimen was entirely processed for histological evaluation, requiring 53 slides. Tumor dermal invasion was detected in only three out of 53 glass slides as the invasiveness was not identified by clinical, dermatoscopy or macroscopy exams.Conclusion: Sectioning through the entire lesion is considered very important to determinate the appropriate stage of the disease and the correct treatment and patient follow-up.

Chronic reparative changes in medium-sized vessels in a case of primary cutaneous anaplastic large-cell lymphoma with angioinvasive features and cytotoxic phenotype: new histopathological findings in line with indolent clinical behavior

Angioinvasion/angiodestruction has been reported in a small subset of primary cutaneous anaplastic large-cell lymphomas (PCALCL). Recently, PCALCL with angioinvasive features and cytotoxic phenotype has been characterized as a variant associated with good clinical outcomes despite worrisome histopathologic features. We report a case of PCALCL with angioinvasive features and cytotoxic phenotype associated with reparative changes on the wall of medium-sized vessels involved by the neoplasm, including intimal fibroblastic proliferation and luminal obliteration. This vascular pattern, although previously unreported in PCALCL, is in accordance with the indolent behavior observed in this entity and provides a further link with lymphomatoid papulosis type E.