Proposal of a histopathological predictive rule for the differential diagnosis between American tegumentary leishmaniasis and sporotrichosis skin lesions.

BACKGROUND: American tegumentary leishmaniasis (ATL) and sporotrichosis exhibit similar histopathology and low frequencies of microorganism detection. OBJECTIVES: This study seeks to identify microscopic alterations that can distinguish between these diseases. METHODS: Haematoxylin and eosin stained slides of 171 ATL and 97 sporotrichosis samples from active cutaneous lesions were examined for histopathological alterations. The lesions were diagnosed by isolating the agent (which was not visible) in culture. An intuitive diagnosis was assigned to each slide. The strength of the association between the histopathological findings and the diagnosis was estimated by an odds ratio, and each finding was graded according to a regression model. A score was assigned to each sample based on the histopathological findings. A study of the interobserver reliability was performed by calculating kappa coefficients of the histopathological findings and intuitive diagnoses. RESULTS: The markers 'macrophage concentration', 'tuberculoid granuloma' and 'extracellular matrix degeneration' were associated with ATL. 'Suppurative granuloma', 'stellate granuloma', 'different types of giant cells', 'granulomas in granulation tissue' and 'abscess outside the granuloma' were associated with a diagnosis of sporotrichosis. 'Macrophage concentration' and 'suppurative granuloma' had the highest (substantial and almost perfect, respectively) reliability. The regression model score indicated 92.0% accuracy. The intuitive diagnosis had 82.5% diagnostic accuracy and substantial reliability. CONCLUSIONS: Taking into account the clinical and epidemiological context, some histopathological alterations might be useful for the differential diagnosis between ATL and sporotrichosis cutaneous lesions in cases in which the aetiological agent is not visible.

Immunophenotypic aspects of cylindroma and nodular hidradenoma.

BACKGROUND: Some adnexal tumours have many controversies about their histogenesis. OBJECTIVES: To evaluate the eccrine and/or apocrine differentiation phenotype in cases of cylindroma and clear cell hidradenoma with CD15 and p63 antibodies. METHODOLOGY: Slides and blocks of six cases of cylindroma and seven cases of nodular hidradenoma (clear cells) were analyzed by the technique of immunohistochemistry with CD15 and p63 antibodies. RESULTS: In all cases of cylindroma we obtained negative results for CD15 antibody and positive for p63 antibody. In five of seven cases of nodular hidradenoma (clear cell), we could easily observe clear cells between 20% and 50% of tumour cells. In the two other cases, cystic lesions were present and occasional clear cells could be seen. The reaction with CD15 antibody was positive in granular and cytoplasmic pattern in six of seven cases, especially in cells with suggestive clear cytoplasm in lower proportion than this clear cells could be seen in haematoxylin and eosin. The positivity for p63 antibody, nuclear pattern, was observed in six of seven cases, in the major part of tumour cells. In only one case, the positivity was in 20% of cells. Limitation Samples are in small number because these are relatively rare tumours. CONCLUSIONS: The present study suggests eccrine origin for both tumours: cylindroma and clear cell hidradenoma.

Oral isotretinoin in photoaging: clinical and histopathological evidence of efficacy of an off-label indication.

BACKGROUND: Despite evidences of the beneficial clinical effects of oral isotretinoin in the treatment of cutaneous photoaging, scientific evidences are still scarce, mainly supported by histopathological and morphometric studies. OBJECTIVES: To analyse possible clinical and morphological changes resulting from the treatment of photoaging with oral isotretinoin. METHODS: Thirty female patients, aged 40 to 55 years, phototypes II to IV, with moderate to severe photoaging were randomly assigned to two groups of 15 each. Group I (G I) patients were treated with 10 mg of isotretinoin and group II (G II) with 20 mg of oral isotretinoin thrice a week for 3 months. Skin biopsies were performed before and after the end of therapy, and the various sections were submitted to specific staining for collagen and elastic fibres. To analyse the changes, morphometric studies were performed, and the results obtained were analysed by Student's t-test (paired and non-paired). Clinical results of therapy regarding texture, colouring and aspect of the wrinkles were assessed by both physician and patient. RESULTS: The increase in the amount of collagen fibres was statistically significant with both dosage regimens (mean, 37.8%, increasing to 44.4%; P = 0.029 with the 10-mg dosage; and mean, 36.6%, increasing to 41.9%; P = 0.01 with the 20-mg dosage). A pattern pointing toward a decrease in the number of elastic fibres was found (mean, 15.3-12%; P = 0.014 with the 10-mg dosage; mean, 15.5-14%; P = 0.125 with the 20-mg dosage). Additionally, there was improvement in the general aspect of the skin, regarding texture, wrinkles depth and skin coloration. LIMITATIONS: Despite ethical considerations, a lack of a control group using placebo may render the results less accurate. CONCLUSION: Low dosages of oral isotretinoin seem to be an effective therapeutic option for cutaneous photoaging.

American cutaneous leishmaniasis in two cats from Rio de Janeiro, Brazil: first report of natural infection with Leishmania (Viannia) braziliensis.

We describe the isolation of Leishmania (Viannia) braziliensis from two female cats with American cutaneous leishmaniasis in Rio de Janeiro, Brazil. The isolates were identified as L. (V.) braziliensis by isoenzyme electrophoresis.

Oral lichen planus and dermal dendrocytes.

INTRODUCTION: Oral lichen planus (OLP) is a relatively common inflammatory disease with a wide range of clinical forms. Its pathogenesis has not been fully elucidated although it is known to be mediated by lymphocytes with the participation of cytokines and other inflammatory cells, including type I and type II dermal dendrocytes (DD) (factor XIIIa+ DD and CD34+ DD, respectively). OBJECTIVES: To describe the presence and tissue distribution of these cells, through immunohistochemistry, in 23 specimens from patients with clinical and histopathological criteria of OLP. RESULTS: Factor XIIIa+ DD were mainly located in the superficial dermis (p < 0.0001) as opposed to the deep submucosa. These cells were abundant throughout the dermal-epidermal junction and closely related to lymphocyte infiltration. Moreover, factor XIIIa+ DD were also found in the epithelium and deep dermis. CD34+ DD were distributed mostly to the deep dermis directly below the lymphocyte infiltrate with few cells in the subepithelial region. CONCLUSIONS: DD were present in OLP, with distinct tissue distributions. Factor XIIIa+ DD were predominant in the superficial dermis while CD34+ DD could be found mostly in the deep dermis. These findings suggest that DD, and those positive for factor XIIIa+ in particular in view of their ability to express intercellular adhesion molecule-1 (ICAM-1) and tumor necrosis factor alpha (TNF-alpha), may play an important role in pathogenesis of OLP.

Oral lesions in leprosy.

BACKGROUND: Leprotic oral lesions are more common in the lepromatous form of leprosy, indicate a late manifestation, and have a great epidemiological importance as a source of infection. METHODS: Patients with leprosy were examined searching for oral lesions. Biopsies of the left buccal mucosa in all patients, and of oral lesions, were performed and were stained with H & E and Wade. RESULTS: Oral lesions were found in 26 patients, 11 lepromatous leprosy, 14 borderline leprosy, and one tuberculoid leprosy. Clinically 5 patients had enanthem of the anterior pillars, 3 of the uvula and 3 of the palate. Two had palatal infiltration. Viable bacilli were found in two lepromatous patients. Biopsies of the buccal mucosa showed no change or a nonspecific inflammatory infiltrate. Oral clinical alterations were present in 69% of the patients; of these 50% showed histopathological features in an area without any lesion. DISCUSSION: Our clinical and histopathological findings corroborate earlier reports that there is a reduced incidence of oral changes, which is probably due to early treatment. The maintenance of oral infection in this area can also lead to and maintain lepra reactions, while they may also act as possible infection sources. Attention should be given to oral disease in leprosy because detection and treatment of oral lesions can prevent the spread of the disease.